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MODEL GFC 7000TA
CARBON DIOXIDE ANALYZER
Operation Manual
Also supports operation of:
GFC 7000T CO
2
Analyzer
(when used in conjunction with GFC 7000T Addendum, PN 07273)
P/N M07272
DATE 06/04/13
TELEDYNE ELECTRONIC TECHNOLOGIES
Analytical Instruments
16830 Chestnut Street
City of Industry, CA 91748
Telephone: (626) 934-1500
Fax: (626) 961-2538
Web: www.teledyne-ai.com
Teledyne Analytical Instruments
Model GFC7000TA Carbon Dioxide Analyzer
Copyright © 2013 Teledyne Analytical Instruments
All Rights Reserved. No part of this manual may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other language or computer language in whole or in part, in any form or by any means, whether it be electronic, mechanical, magnetic, optical, manual, or otherwise, without the prior written consent of Teledyne Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 91748.
Warranty
This equipment is sold subject to the mutual agreement that it is warranted by us free from defects of material and of construction, and that our liability shall be limited to replacing or repairing at our factory (without charge, except for transportation), or at customer plant at our option, any material or construction in which defects become apparent within one year from the date of shipment, except in cases where quotations or acknowledgements provide for a shorter period. Components manufactured by others bear the warranty of their manufacturer. This warranty does not cover defects caused by wear, accident, misuse, neglect or repairs other than those performed by Teledyne or an authorized service center. We assume no liability for direct or indirect damages of any kind and the purchaser by the acceptance of the equipment will assume all liability for any damage which may result from its use or misuse.
We reserve the right to employ any suitable material in the manufacture of our apparatus, and to make any alterations in the dimensions, shape or weight of any parts, in so far as such alterations do not adversely affect our warranty.
Important Notice
This instrument provides measurement readings to its user, and serves as a tool by which valuable data can be gathered. The information provided by the instrument may assist the user in eliminating potential hazards caused by his process; however, it is essential that all personnel involved in the use of the instrument or its interface be properly trained in the process being measured, as well as all instrumentation related to it.
The safety of personnel is ultimately the responsibility of those who control process conditions. While this instrument may be able to provide early warning of imminent danger, it has no control over process conditions, and it can be misused. In particular, any alarm or control systems installed must be tested and understood, both as to how they operate and as to how they can be defeated. Any safeguards required such as locks, labels, or redundancy, must be provided by the user or specifically requested of Teledyne at the time the order is placed.
Therefore, the purchaser must be aware of the hazardous process conditions. The purchaser is responsible for the training of personnel, for providing hazard warning methods and instrumentation per the appropriate standards, and for ensuring that hazard warning devices and instrumentation are maintained and operated properly.
Teledyne Analytical Instruments, the manufacturer of this instrument, cannot accept responsibility for conditions beyond its knowledge and control. No statement expressed or implied by this document or any information disseminated by the manufacturer or its agents, is to be construed as a warranty of adequate safety control under the user’s process conditions.
Trademarks
All trademarks, registered trademarks, brand names or product names appearing in this document are the property of their respective owners and are used herein for identification purposes only.
Teledyne Analytical Instruments ii
Model GFC7000TA Carbon Dioxide Analyzer
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Teledyne Analytical Instruments iii
Safety Messages Model GFC7000TA Carbon Dioxide Analyzer
SAFETY MESSAGES
Important safety messages are provided throughout this manual for the purpose of avoiding personal injury or instrument damage. Please read these messages carefully. Each safety message is associated with a safety alert symbol, and are placed throughout this manual; the safety symbols are also located inside the instrument.
It is imperative that you pay close attention to these messages, the descriptions of which are as follows:
WARNING : Electrical Shock Hazard
HAZARD : Strong oxidizer
GENERAL WARNING/CAUTION : Read the accompanying message for specific information.
CAUTION : Hot Surface Warning
Do Not Touch : Touching some parts of the instrument without protection or proper tools could result in damage to the part(s) and/or the instrument.
Technician Symbol : All operations marked with this symbol are to be performed by qualified maintenance personnel only.
Electrical Ground : This symbol inside the instrument marks the central safety grounding point for the instrument.
CAUTION
This instrument should only be used for the purpose and in the manner described in this manual. If you use this instrument in a manner other than that for which it was intended, unpredictable behavior could ensue with possible hazardous consequences.
NEVER use any gas analyzer to sample combustible gas(es)!
Note: Technical Assistance regarding the use and maintenance of the GFC7001TA or any other Teledyne product can be obtained by contacting Teledyne Customer
Service Department:
Phone: 888-789-8168
Email: [email protected]
or by accessing various service options on our website at http://www.teledyne-ai.com/
Teledyne Analytical Instruments v
Safety Messages Model GFC7000TA Carbon Dioxide Analyzer
CONSIGNES DE SÉCURITÉ
Des consignes de sécurité importantes sont fournies tout au long du présent manuel dans le but d’éviter des blessures corporelles ou d’endommager les instruments. Veuillez lire attentivement ces consignes.
Chaque consigne de sécurité est représentée par un pictogramme d’alerte de sécurité; ces pictogrammes se retrouvent dans ce manuel et à l’intérieur des instruments. Les symboles correspondent aux consignes suivantes :
AVERTISSEMENT : Risque de choc électrique
DANGER : Oxydant puissant
AVERTISSEMENT GÉNÉRAL / MISE EN GARDE : Lire la consigne complémentaire pour des renseignements spécifiques
MISE EN GARDE : Surface chaude
Ne pas toucher : Toucher à certaines parties de l’instrument sans protection ou sans les outils appropriés pourrait entraîner des dommages aux pièces ou à l’instrument.
Pictogramme « technicien » : Toutes les opérations portant ce symbole doivent
être effectuées uniquement par du personnel de maintenance qualifié.
Mise à la terre : Ce symbole à l’intérieur de l’instrument détermine le point central de la mise à la terre sécuritaire de l’instrument.
MISE EN GARDE
Cet instrument doit être utilisé aux fins décrites et de la manière décrite dans ce manuel. Si vous utilisez cet instrument d’une autre manière que celle pour laquelle il a été prévu, l’instrument pourrait se comporter de façon imprévisible et entraîner des conséquences dangereuses.
NE JAMAIS utiliser un analyseur de gaz pour échantillonner des gaz combustibles!
Teledyne Analytical Instruments vi
Safety Messages Model GFC7000TA Carbon Dioxide Analyzer
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Teledyne Analytical Instruments vii
Manual Information Model GFC7000TA Carbon Dioxide Analyzer
ABOUT THIS MANUAL
This manual, PN 07272, provides operation instructions for the GFC 7000TA Analyzer, and supports operation of the Model GFC 7000T (when used in conjunction with the
GFC 7000T Addendum, PN 07273). This manual is comprised of multiple documents as listed below.
Part No. Rev
07272 A
Name/Description
GFC 7000TA Carbon Dioxide Analyzer Operation Manual
05233 H Menu trees and software documentation (inserted as Appendix A of this manual)
06879 1/4/2011 Spare Parts List (located in Appendix B, this manual)
04411 M
05235 C
0691201 B
Recommended Spare Parts Stocking Levels
Repair Request Questionnaire (inserted as Appendix C of this manual)
Interconnects and Schematics included in Appendix D of this manual
Interconnect Wire List (located in Appendix D of this manual)
069121 B
03297 K
03632 A
04003 N
04089 A
04136 B
04468 B
05803 B
06698 D
06882 B
06731 A
Interconnect Wiring Diagram (located in Appendix D of this manual)
PCA, 03296, IR Photodetector Preamp and Sync Demodulator
PCA, 03631, 0-20mA driver
PCA, 04003, Pressure/Flow Transducer Interface
PCA, 04088, Opto Pickup Interface
PCA, 04135 Rev A, Relay
PCA, 04467, Analog Output Series Res
SCH, PCA 05802, MOTHERBOARD, GEN-5
SCH, PCA 06697, INTRFC, LCD TCH SCRN,
SCH, LVDS TRANSMITTER BOARD
SCH, AUXILLIARY-I/O BOARD
NOTE
Please read this manual in its entirety before operating the instrument.
Teledyne Analytical Instruments ix
Manual Information
2010, T360 Manual, PN0 Rev A, DCN
Model GFC7000TA Carbon Dioxide Analyzer
0xxxx X
For the purpose of capturing this manual’s construct at its initial release, the following list documents the current Rev of each part comprising Rev A of this manual. Any future changes to this manual will be recorded in this Revision History section, most recent changes at the top. Their new Rev letters will be updated in the preceding About This Manual section:
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Teledyne Analytical Instruments x
Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
TABLE OF CONTENTS
SAFETY MESSAGES ............................................................................................................................................... v
CONSIGNES DE SÉCURITÉ ................................................................................................................................... vi
ABOUT this MANUAL .............................................................................................................................................. ix
TABLE OF CONTENTS ........................................................................................................................................... xi
1. INTRODUCTION ........................................................................................................................................................ 1
1.1. Features ............................................................................................................................................................. 1
1.2. Using This Manual .............................................................................................................................................. 1
2. SPECIFICATIONS AND APPROVALS ..................................................................................................................... 5
2.1. Specifications ..................................................................................................................................................... 5
2.2. CE Mark Compliance ......................................................................................................................................... 7
3. GETTING STARTED ................................................................................................................................................. 9
3.1. Unpacking and Initial Set Up .............................................................................................................................. 9
3.2. Front Panel ....................................................................................................................................................... 11
3.3. Rear Panel ....................................................................................................................................................... 15
3.4. Internal Layout ................................................................................................................................................. 17
3.5. Electrical Connections ...................................................................................................................................... 19
3.5.1. Power Connection .................................................................................................................................... 20
3.5.2. Connecting Analog Inputs (Option 64) ...................................................................................................... 20
3.5.3. Connecting Analog Outputs ...................................................................................................................... 21
3.5.4. Connecting the Status Outputs ................................................................................................................. 23
3.5.5. Connecting the Control Inputs .................................................................................................................. 24
3.5.6. Connecting the Communications Interfaces ............................................................................................. 25
3.6. Pneumatic Connections ................................................................................................................................... 25
3.6.1. Basic Pneumatic Connections .................................................................................................................. 26
3.6.2. Connections with Internal Valve Options Installed .................................................................................... 30
3.6.3. Pneumatic Connections in Multipoint Calibration Applications.................................................................. 32
3.6.4. Setting the Internal Purge Air Pressure .................................................................................................... 32
3.7. Initial Operation ................................................................................................................................................ 33
3.7.1. Startup ...................................................................................................................................................... 33
3.7.2. Warm Up................................................................................................................................................... 34
3.7.3. Warning Messages ................................................................................................................................... 34
3.7.4. Functional Check ...................................................................................................................................... 36
3.8. Initial Calibration Procedure ............................................................................................................................. 37
3.8.1. Initial O
2
Sensor Calibration Procedure .................................................................................................... 40
4. FREQUENTLY ASKED QUESTIONS ..................................................................................................................... 45
4.1. FAQ’s ............................................................................................................................................................... 45
4.2. Glossary ........................................................................................................................................................... 46
5. OPTIONAL HARDWARE AND SOFTWARE .......................................................................................................... 51
5.1. Rack Mount Kits (Options 20A, 20B, 21 and 23) .............................................................................................. 51
5.2. Current Loop Analog Outputs (Option 41) ........................................................................................................ 51
5.2.1. Converting Current Loop Analog Outputs to Standard Voltage Outputs ................................................... 52
5.3. Expendable Kits (Options 42C, 42D and 43) .................................................................................................... 53
5.4. Calibration Valves Options ............................................................................................................................... 54
5.4.1. Ambient Zero/Pressurized Span Valve ..................................................................................................... 54
5.4.2. Ambient Zero/Ambient Span Valve ........................................................................................................... 55
5.5. Communication Options ................................................................................................................................... 57
5.5.1. Communications Cables ........................................................................................................................... 57
5.5.2. RS-232 Multidrop (Option 62) ................................................................................................................... 57
5.6. Oxygen Sensor (OPT 65) ................................................................................................................................. 58
5.6.1. Theory of Operation .................................................................................................................................. 58
5.7. Special Features .............................................................................................................................................. 61
5.7.1. Dilution Ratio Option ................................................................................................................................. 61
5.7.2. Maintenance Mode Switch ........................................................................................................................ 61
5.7.3. Second Language Switch ......................................................................................................................... 61
6. OPERATING INSTRUCTIONS ................................................................................................................................ 63
6.1. Overview of Operating modes .......................................................................................................................... 63
6.2. Sample Mode ................................................................................................................................................... 64
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
6.2.1. Test Functions .......................................................................................................................................... 65
6.2.2. Warning Messages ................................................................................................................................... 67
6.3. Calibration Mode .............................................................................................................................................. 68
6.4. SETUP MODE.................................................................................................................................................. 69
6.5. SETUP CFG: Viewing the Analyzer’s Configuration Information ................................................................. 70
6.6. SETUP ACAL: Automatic Calibration .......................................................................................................... 70
6.7. SETUP DAS: Using the Data Acquisition System (DAS) ............................................................................. 71
6.7.1. DAS Structure ........................................................................................................................................... 72
6.7.2. Default DAS Channels .............................................................................................................................. 74
6.7.3. Remote DAS Configuration....................................................................................................................... 88
6.8. SETUP RNGE: Analog Output Reporting Range Configuration .................................................................. 89
6.8.1. Physical Range versus Analog Output Reporting Ranges ........................................................................ 90
6.8.2. Reporting Range Modes ........................................................................................................................... 90
6.8.3. Single Range Mode (SNGL) ..................................................................................................................... 92
6.8.4. Dual Range Mode (DUAL) ........................................................................................................................ 93
6.8.5. Auto Range Mode (AUTO)........................................................................................................................ 94
6.8.6. Range Units .............................................................................................................................................. 95
6.8.7. Dilution Ratio ............................................................................................................................................ 96
6.9. SETUP PASS: Password Feature ............................................................................................................... 97
6.10. SETUP CLK: Setting the Internal Time-of-Day Clock ................................................................................ 99
6.11. SETUP MORE COMM: Using the Analyzer’s Communication Ports .................................................... 101
6.11.1. Analyzer ID ........................................................................................................................................... 101
6.11.2. COM Port Default Settings .................................................................................................................... 102
6.11.3. RS-485 Configuration of COM2 ............................................................................................................ 105
6.11.4. DTE and DCE Communication ............................................................................................................. 105
6.11.5. COM Port Communication Modes ........................................................................................................ 106
6.11.6. Remote Access via the Ethernet ........................................................................................................... 108
6.11.7. Multidrop RS-232 Set Up ...................................................................................................................... 114
6.11.8. COM Port Baud Rate ............................................................................................................................ 116
6.11.9. COM Port Testing ................................................................................................................................. 117
6.12. SETUP MORE VARS: Internal Variables (VARS) ............................................................................... 118
6.13. SETUP MORE DIAG: Using the Diagnostics Functions ..................................................................... 120
6.13.1. Accessing the Diagnostic Features ....................................................................................................... 121
6.13.2. Signal I/O .............................................................................................................................................. 121
6.13.3. Analog Output Step Test ...................................................................................................................... 122
6.13.4. Analog I/O Configuration ...................................................................................................................... 123
6.13.5. Electric Test .......................................................................................................................................... 136
6.13.6. Dark Calibration Test ............................................................................................................................ 137
6.13.7. Pressure Calibration ............................................................................................................................. 138
6.13.8. Flow Calibration .................................................................................................................................... 139
6.13.9. Test Channel Output ............................................................................................................................. 140
6.14. SETUP MORE ALRM: Using the Gas Concentration Alarms ............................................................... 141
6.14.1. Setting the Concentration Alarm Limits ................................................................................................. 142
6.15. Remote Operation of the Analyzer ............................................................................................................... 142
6.15.1. Remote Operation Using the External Digital I/O .................................................................................. 142
6.15.2. Remote Operation Using the External Serial I/O .................................................................................. 146
6.15.3. Additional Communications Documentation ......................................................................................... 153
6.15.4. Using the GFC 7000TA with a Hessen Protocol Network ..................................................................... 153
7. CALIBRATION PROCEDURES ............................................................................................................................ 161
7.1. Before Calibration ........................................................................................................................................... 161
7.1.1. Zero Air and Span Gas ........................................................................................................................... 161
7.1.2. Calibration Gas Traceability .................................................................................................................... 162
7.1.3. Data Recording Devices ......................................................................................................................... 162
7.2. Manual Calibration without Zero/Span Valves ................................................................................................ 162
7.3. Manual Calibration Checks ............................................................................................................................ 165
7.4. Manual Calibration with Zero/Span Valves ..................................................................................................... 166
7.5. Manual Calibration Checks with Zero/Span Valves ........................................................................................ 171
7.5.1. Zero/Span Calibration on Auto Range or Dual Ranges .......................................................................... 172
7.5.2. Use of Zero/Span Valves with Remote Contact Closure ........................................................................ 173
7.6. Automatic Zero/Span Cal/Check (AutoCal) .................................................................................................... 173
7.6.1. AutoCal with Auto or Dual Reporting Ranges Modes Selected .............................................................. 176
7.7. Calibration Quality .......................................................................................................................................... 176
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
8. MAINTENANCE SCHEDULE & PROCEDURES .................................................................................................. 179
8.1. Maintenance Schedule ................................................................................................................................... 179
8.2. Predicting Failures Using the Test Functions ................................................................................................. 183
8.3. Maintenance Procedures ............................................................................................................................... 184
8.3.1. Replacing the Sample Particulate Filter .................................................................................................. 184
8.3.2. Rebuilding the Sample Pump ................................................................................................................. 185
8.3.3. Performing Leak Checks ........................................................................................................................ 185
8.3.4. Performing a Sample Flow Check .......................................................................................................... 186
8.3.5. Cleaning the Optical Bench .................................................................................................................... 186
8.3.6. Cleaning Exterior Surfaces of the GFC 7000TA ..................................................................................... 186
9. THEORY OF OPERATION .................................................................................................................................... 187
9.1. Measurement Method .................................................................................................................................... 187
9.1.1. Beer’s Law .............................................................................................................................................. 187
9.1.2. Measurement Fundamentals .................................................................................................................. 187
9.1.3. Gas Filter Correlation .............................................................................................................................. 188
9.1.4. Interference and Signal to Noise Rejection ............................................................................................. 190
9.2. Pneumatic Operation ...................................................................................................................................... 193
9.2.1. Sample Gas Flow ................................................................................................................................... 194
9.2.2. Flow Rate Control ................................................................................................................................... 194
9.2.3. Purge Gas Pressure Control ................................................................................................................... 196
9.2.4. Particulate Filter ...................................................................................................................................... 196
9.2.5. Pneumatic Sensors ................................................................................................................................. 196
9.3. Electronic Operation ....................................................................................................................................... 197
9.3.1. Overview ................................................................................................................................................. 197
9.3.2. CPU ........................................................................................................................................................ 199
9.3.3. Optical Bench & GFC Wheel .................................................................................................................. 200
9.3.4. Synchronous Demodulator (Sync/Demod) Assembly ............................................................................. 202
9.3.5. Relay Board ............................................................................................................................................ 205
9.3.6. Mother Board .......................................................................................................................................... 207
9.3.7. I 2 C Data Bus ........................................................................................................................................... 210
9.3.8. Power Supply/ Circuit Breaker ................................................................................................................ 211
9.4. Front Panel Touchscreen/Display Interface ................................................................................................... 212
9.4.1. LVDS Transmitter Board ......................................................................................................................... 212
9.4.2. Front Panel Touchscreen/Display Interface PCA .................................................................................... 212
9.5. Software Operation ........................................................................................................................................ 213
9.5.1. Adaptive Filter ......................................................................................................................................... 213
9.5.2. Calibration - Slope and Offset ................................................................................................................. 214
9.5.3. Measurement Algorithm .......................................................................................................................... 214
9.5.4. Temperature and Pressure Compensation ............................................................................................. 215
9.5.5. Internal Data Acquisition System (DAS) ................................................................................................. 215
10. TROUBLESHOOTING & REPAIR PROCEDURES ............................................................................................ 217
10.1. General Troubleshooting Hints ..................................................................................................................... 217
10.1.1. Interpreting WARNING Messages ........................................................................................................ 218
10.1.2. Fault Diagnosis with TEST Functions ................................................................................................... 221
10.1.3. Using the Diagnostic Signal I/O Function ............................................................................................. 223
10.1.4. Internal Electronic Status LEDs ............................................................................................................ 224
10.2. Gas Flow Problems ...................................................................................................................................... 228
10.2.1. GFC 7000TA Internal Gas Flow Diagrams ........................................................................................... 229
10.2.2. Typical Sample Gas Flow Problems ..................................................................................................... 232
10.2.3. Poor or Stopped Flow of Purge Gas ..................................................................................................... 234
10.3. Calibration Problems .................................................................................................................................... 235
10.3.1. Miscalibrated ......................................................................................................................................... 235
10.3.2. Non-Repeatable Zero and Span ........................................................................................................... 236
10.3.3. Inability to Span – Touchscreen SPAN Button Not Visible ................................................................... 236
10.3.4. Inability to Zero – Touchscreen ZERO Button Not Visible .................................................................... 237
10.4. Other Performance Problems ....................................................................................................................... 238
10.4.1. Temperature Problems ......................................................................................................................... 238
10.4.2. Excessive Noise ................................................................................................................................... 240
10.5. Subsystem Checkout ................................................................................................................................... 241
10.5.1. AC Mains Configuration ........................................................................................................................ 241
10.5.2. DC Power Supply ................................................................................................................................. 241
10.5.3. I 2 C Bus .................................................................................................................................................. 242
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
10.5.4. Touchscreen Interface .......................................................................................................................... 242
10.5.5. LCD Display Module ............................................................................................................................. 242
10.5.6. Relay Board .......................................................................................................................................... 243
10.5.7. Sensor Assembly .................................................................................................................................. 243
10.5.8. Motherboard ......................................................................................................................................... 245
10.5.9. CPU ...................................................................................................................................................... 249
10.5.10. RS-232 Communications .................................................................................................................... 249
10.6. Repair Procedures ....................................................................................................................................... 251
10.6.1. Repairing Sample Flow Control Assembly ............................................................................................ 251
10.6.2. Removing/Replacing the GFC Wheel ................................................................................................... 252
10.6.3. Disk-On-Module Replacement Procedure ............................................................................................ 253
11. A PRIMER ON ELECTRO-STATIC DISCHARGE ............................................................................................... 255
11.1. How Static Charges are Created .................................................................................................................. 255
11.2. How Electro-Static Charges Cause Damage ............................................................................................... 256
11.3. Common Myths About ESD Damage ........................................................................................................... 257
11.4. Basic Principles of Static Control .................................................................................................................. 257
LIST OF APPENDICES
APPENDIX A - VERSION SPECIFIC SOFTWARE DOCUMENTATION, L.8
APPENDIX A-1: Models GFC 7000TA and GFC 7000E Software Menu Trees
APPENDIX A-2: GFC 7000 Series Setup Variables
APPENDIX A-3: GFC 7000 Series Warnings and Test Measurements
APPENDIX A-4: GFC 7000 Series Signal I/O Definitions
APPENDIX A-5: GFC 7000 Series DAS Triggering Events
APPENDIX A-6: GFC 7000 Series DAS Parameters
APPENDIX A-7: Terminal Command Designators
APPENDIX A-8: Terminal Key Assignments
APPENDIX A-9: GFC 7000 Series MODBUS Register
APPENDIX B - SPARE PARTS LIST and RECOMMENDED SPARES STOCKING LEVELS
APPENDIX C - REPAIR QUESTIONNAIRE
APPENDIX D - ELECTRONIC SCHEMATICS
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
LIST OF FIGURES
Figure 3-1:
Figure 3-2:
Figure 3-3:
Figure 3-4:
Figure 3-5:
Figure 3-6:
Figure 3-7:
Figure 3-8:
Front Panel Layout ...................................................................................................................... 11
Display Screen and Touch Control ............................................................................................. 12
Display/Touch Control Screen Mapped to Menu Charts ............................................................. 14
Rear Panel Layout ....................................................................................................................... 15
Internal Chassis Layout ............................................................................................................... 17
Optical Bench Layout .................................................................................................................. 18
GFC 7000TA Internal Gas Flow .................................................................................................. 19
Analog In Connector .................................................................................................................... 20
Figure 3-9: Pneumatic Connections–Basic Configuration–Using Bottled Span Gas .................................... 27
Figure 3-10: Pneumatic Connections–Basic Configuration–Using Gas Dilution Calibrator ............................ 27
Figure 3-11: Pneumatic Connections with Ambient Zero/Ambient Span Valves (OPT 50A) .......................... 30
Figure 3-12: Pneumatic Connections with Ambient Zero/Ambient Span Valves (Opt 50A) and
External Zero Air Scrubber .......................................................................................................... 30
Figure 3-13: Pneumatic Connections with Ambient Zero/Pressurized Span Valves (OPT 50B) .................... 31
Figure 3-14: Pneumatic Connections with Ambient Zero/Pressurized Span Valves (Opt 50B) and
External Zero Air Scrubber .......................................................................................................... 31
Figure 3-15: Example of Pneumatic Set up for Multipoint Calibration ............................................................. 32
Figure 3-16: O2 Sensor Calibration Set Up ..................................................................................................... 40
Figure 5-1:
Figure 5-2:
Figure 5-3:
Figure 5-4:
Figure 5-5:
Figure 5-6:
Figure 6-1:
Figure 6-2:
Figure 6-3:
Figure 6-4:
Current Loop Option Installed on the Motherboard ..................................................................... 52
Internal Pneumatic Flow – Ambient Zero/Pressurized Span Valves ........................................... 55
Internal Pneumatic Flow – Ambient Zero/Ambient Span ............................................................ 56
Multi-drop/LVDS PCA Seated on CPU ....................................................................................... 58
Figure 6-5:
Figure 6-6:
Figure 6-7:
Figure 6-8:
Oxygen Sensor - Principle of Operation ...................................................................................... 59
GFC 7000TA – Internal Pneumatics with O2 Sensor Option 65 ................................................. 60
Front Panel Display ..................................................................................................................... 63
Viewing TEST Functions ............................................................................................................. 66
Viewing and Clearing GFC 7000TA WARNING Messages ........................................................ 68
Default DAS Channels Setup ...................................................................................................... 75
APICOM User Interface for DAS Configuration .......................................................................... 88
Analog Output Connector Pin Out ............................................................................................... 89
Rear Panel Connector Pin-Outs for COM1 & COM2 in RS-232 Mode ..................................... 103
CPU Connector Pin-Outs for COM1 & COM2 in RS-232 Mode ............................................... 104
Figure 6-9: Multidrop/LVDS PCA Seated on CPU ....................................................................................... 114
Figure 6-10: RS232-Multidrop PCA Host/Analyzer Interconnect Diagram .................................................... 115
Figure 6-11: Setup for Calibrating Analog Voltage Outputs .......................................................................... 130
Figure 6-12: Setup for Calibrating Current Outputs ....................................................................................... 132
Figure 6-13: Status Output Connector ........................................................................................................... 143
Figure 6-14: Control Inputs ............................................................................................................................ 145
Figure 6-15: APICOM Remote Control Program Interface ............................................................................ 152
Figure 7-1:
Figure 7-2:
Figure 7-3:
Figure 7-4:
Pneumatic Connections–Basic Configuration–Using Bottled Span Gas .................................. 162
Pneumatic Connections–Basic Configuration–Using Gas Dilution Calibrator .......................... 163
Figure 7-5:
Figure 7-6:
Figure 8-1:
Figure 9-1:
Figure 9-2:
Figure 9-3:
Figure 9-4:
Figure 9-5:
Pneumatic Connections – Ambient Zero/Pressurized Span Valves ........................................ 166
Pneumatic Connections – Ambient Zero/Pressurized Span Valves and External Zero Air
Scrubber .................................................................................................................................... 167
Pneumatic Connections – Ambient Zero/Ambient Span Valves ............................................... 167
Pneumatic Connections – Ambient Zero/Ambient Span Valves with External Zero Air
Scrubber .................................................................................................................................... 168
Sample Particulate Filter Assembly .......................................................................................... 184
Measurement Fundamentals ..................................................................................................... 188
GFC Wheel ................................................................................................................................ 188
Measurement Fundamentals with GFC Wheel ......................................................................... 189
Affect of CO2 in the Sample on CO2 MEAS & CO2 REF ......................................................... 190
Effects of Interfering Gas on CO2 MEAS & CO2 REF .............................................................. 191
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
Figure 9-6:
Figure 9-7:
Figure 9-8:
Figure 9-9:
Chopped IR Signal .................................................................................................................... 191
Internal Pneumatic Flow – Basic Configuration ........................................................................ 194
Flow Control Assembly & Critical Flow Orifice .......................................................................... 195
GFC 7000TA Electronic Block Diagram .................................................................................... 198
Figure 9-10: CPU Board ................................................................................................................................ 199
Figure 9-11: GFC Light Mask ........................................................................................................................ 201
Figure 9-12: Segment Sensor and M/R Sensor Output ................................................................................. 202
Figure 9-13: GFC 7000TA Sync / Demod Block Diagram ............................................................................. 203
Figure 9-14: Sample & Hold Timing ............................................................................................................... 204
Figure 9-15: Location of relay board Status LED’s ........................................................................................ 207
Figure 9-16: Power Distribution Block Diagram ............................................................................................. 211
Figure 9-17: Front Panel and Display Interface Block Diagram .................................................................... 212
Figure 9-18: Basic Software Operation .......................................................................................................... 213
Figure 10-1: Viewing and Clearing Warning Messages ................................................................................ 219
Figure 10-2: Example of Signal I/O Function ................................................................................................. 224
Figure 10-3: CPU Status Indicator ................................................................................................................. 225
Figure 10-4: Sync/Demod Board Status LED Locations ............................................................................... 226
Figure 10-5: Relay Board Status LEDs .......................................................................................................... 226
Figure 10-6: GFC 7000TA – Basic Internal Gas Flow ................................................................................... 229
Figure 10-7: Internal Pneumatic Flow – Ambient Zero/Pressurized Span Valves ......................................... 230
Figure 10-8: Internal Pneumatic Flow – Ambient Zero/Ambient Span .......................................................... 231
Figure 10-9: GFC 7000TA – Internal Pneumatics with O
2
Sensor Option 65A ............................................. 232
Figure 10-10: Critical Flow Restrictor Assembly Disassembly ........................................................................ 251
Figure 10-11: Opening the GFC Wheel Housing ............................................................................................. 252
Figure 10-12: Removing the GFC Wheel ........................................................................................................ 253
Figure 11-1: Triboelectric Charging ............................................................................................................... 255
Figure 11-2: Basic anti-ESD Work Station ..................................................................................................... 258
LIST OF TABLES
Table 2-1: Model GFC 7000TA Basic Unit Specifications ..................................................................................... 5
Table 3-1: Display and Touchscreen Control Description ................................................................................... 13
Table 3-2: Rear Panel Description ....................................................................................................................... 16
Table 3-3: Analog Input Pin Assignments ............................................................................................................ 21
Table 3-4: GFC 7000TA Analog Output Pin Outs ................................................................................................ 22
Table 3-5: Status Output Pin-outs ........................................................................................................................ 23
Table 3-6: Control Input Pin-outs ......................................................................................................................... 24
Table 3-7: Rear Panel Pneumatic Connections ................................................................................................... 26
Table 3-8: Front Panel Display During System Warm-Up ................................................................................... 34
Table 3-9: Possible Warning Messages at Start-Up ............................................................................................ 35
Table 5-1: Ambient Zero/Pressurized Span Valve Operating States .................................................................. 54
Table 5-2: Ambient Zero/Ambient Span Valve Operating States ........................................................................ 55
Table 6-1: Analyzer Operating modes ................................................................................................................. 64
Table 6-2: Test Functions Defined ....................................................................................................................... 65
Table 6-3: List of Warning Messages .................................................................................................................. 67
Table 6-4: Primary Setup Mode Features and Functions .................................................................................... 69
Table 6-5: Secondary Setup Mode Features and Functions ............................................................................... 69
Table 6-6: Front Panel Sample LED Status Indicators for DAS .......................................................................... 71
Table 6-7: DAS Data Channel Properties ............................................................................................................ 72
Table 6-8: DAS Data Parameter Functions ......................................................................................................... 73
Table 6-9: Password Levels ................................................................................................................................. 97
Table 6-10: Com Port Communication Modes ..................................................................................................... 106
Table 6-11: Ethernet Status Indicators ................................................................................................................ 108
Table 6-12: LAN/Internet Configuration Properties .............................................................................................. 109
Table 6-13: Internet Configuration Touchscreen Functions ................................................................................. 113
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
Table 6-14: Variable Names (VARS) Revision B.3 .............................................................................................. 118
Table 6-15: GFC 7000TA Diagnostic (DIAG) Functions ...................................................................................... 120
Table 6-16: DIAG - Analog I/O Functions ............................................................................................................ 123
Table 6-17: Analog Output Voltage Ranges ....................................................................................................... 124
Table 6-18: Analog Output Current Loop Range ................................................................................................. 125
Table 6-19: Analog Output Pin Assignments ....................................................................................................... 125
Table 6-20: Voltage Tolerances for Analog Output Calibration ........................................................................... 129
Table 6-21: Current Loop Output Calibration with Resistor ................................................................................. 133
Table 6-22: Test Parameters Available for Analog Output A4 ............................................................................. 140
Table 6-23: CO
2
Concentration Alarm Default Settings ....................................................................................... 141
Table 6-24: Status Output Pin Assignments ........................................................................................................ 144
Table 6-25: Control Input Pin Assignments ......................................................................................................... 145
Table 6-26: Terminal Mode Software Commands ............................................................................................... 146
Table 6-27: Command Types .............................................................................................................................. 147
Table 6-28: Serial Interface Documents .............................................................................................................. 153
Table 6-29: RS-232 Communication Parameters for Hessen Protocol ............................................................... 154
Table 6-30: Teledyne Instruments Hessen Protocol Response Modes .............................................................. 156
Table 6-31: Default Hessen Status Bit Assignments ........................................................................................... 158
Table 7-1: AUTOCAL Modes ............................................................................................................................. 173
Table 7-2: AutoCal ATTRIBUTE Setup Parameters .......................................................................................... 173
Table 7-3: Calibration Data Quality Evaluation .................................................................................................. 176
Table 8-1: GFC 7000TA Maintenance Schedule ............................................................................................... 181
Table 8-2: GFC 7000TA Test Function Record ................................................................................................. 182
Table 8-3: Predictive uses for Test Functions.................................................................................................... 183
Table 9-1: Sync/Demod Status LED Activity ...................................................................................................... 204
Table 9-2: Relay Board Status LED’s ................................................................................................................ 206
Table 10-1: Warning Messages - Indicated Failures ........................................................................................... 220
Table 10-2: Test Functions - Indicated Failures .................................................................................................. 222
Table 10-3: Sync/Demod Board Status Failure Indications ................................................................................. 225
Table 10-4: I2C Status LED Failure Indications ................................................................................................... 226
Table 10-5: Relay Board Status LED Failure Indications .................................................................................... 227
Table 10-6: DC Power Test Point and Wiring Color Codes ................................................................................. 241
Table 10-7: DC Power Supply Acceptable Levels ............................................................................................... 242
Table 10-8: Relay Board Control Devices ............................................................................................................ 243
Table 10-9: Opto Pickup Board Nominal Output Frequencies ............................................................................. 244
Table 10-10: Analog Output Test Function - Nominal Values Voltage Outputs .................................................... 247
Table 10-11: Analog Output Test Function - Nominal Values Current Outputs ..................................................... 247
Table 10-12: Status Outputs Check ....................................................................................................................... 248
Table 11-1: Static Generation Voltages for Typical Activities .............................................................................. 255
Table 11-2: Sensitivity of Electronic Devices to Damage by ESD ....................................................................... 256
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Table of Contents Model GFC7000TA Carbon Dioxide Analyzer
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Teledyne Analytical Instruments xviii
Introduction Model GFC7000TA Carbon Dioxide Analyzer
1. INTRODUCTION
The Models GFC 7000TA and GFC 7000TM differ only in specifications; unless clearly differentiated, both models in this manual are referred to as the GFC 7000TA for simplification. The GFC 7000TA measures carbon dioxide CO
2
by comparing infrared energy absorbed by a sample to that absorbed by a reference according to the Beer-Lambert law. This is accomplished by using a Gas Filter Wheel which alternately allows a high energy infrared light source to pass through a CO
2 with no CO
2
present.
filled chamber and a chamber
The light then travels through the sample cell, which has a folded path. The energy loss through the sample cell is compared with the zero reference signal provided by the gas filter to produce an output proportional to concentration, with little effect from interfering gases within the sample. A nitrogen purge system is provided for the GFC wheel assembly to eliminate the effects of ambient CO
2
, if necessary.
This design produces superior zero and span stability and a high signal-to-noise ratio, allowing excellent sensitivity. Multi-tasking software gives real time indication of numerous operating parameters and provides automatic alarms if diagnostic limits are exceeded
1.1. Features
Ranges, : 0-2 ppm to 0-2000 ppm, GFC 7000TM: 0-4 ppm to 0-4000 ppm, user selectable
Gas Filter Wheel for CO
2
specific measurement
LCD Graphical User Interface with capacitive touch screen
Multi-tasking software allows viewing of test variables during operation
Continuous self checking with alarms
Bi-directional RS-232 and 10/100Base-T Ethernet (optional USB and RS-485) ports for remote operation
Front panel USB ports for peripheral devices
Digital status outputs to indicate instrument operating condition
Adaptive signal filtering to optimize response time
Temperature & Pressure compensation
Internal data logging with 1 min to 24 hour averages
1.2. Using This Manual
This manual has the following data structures:
1 TABLE OF CONTENTS:
Outlines the contents of the manual in the order the information is presented. This is a good overview of the topics covered in the manual. There is also a list of tables, a list of figures and a list of appendices.
2 SPECIFICATIONS
This section contains a list of the analyzer’s performance specifications.
Teledyne Analytical Instruments 1
Introduction Model GFC7000TA Carbon Dioxide Analyzer
3 GETTING STARTED:
Instructions for setting up, installing, and performing a functional check and initial calibration.
4 FAQ
Answers to the most frequently asked questions about operating the analyzer.
5 OPTIONAL HARDWARE & SOFTWARE
A description of optional equipment to add functionality to your analyzer.
6 OPERATION INSTRUCTIONS
This section includes step-by-step instructions for operating the analyzer and using its various features and functions.
7 CALIBRATION PROCEDURES
General information and step by step instructions for calibrating your analyzer.
8 EPA PROTOCOL CALIBRATION
Because CO
2
is not declared a criteria air pollutant by the US EPA, EPA equivalency is not required for this type of analyzer. Therefore no special calibration methods are needed to satisfy EPA requirements.
9 INSTRUMENT MAINTENANCE
Description of certain preventative maintenance procedures that should be regularly performed on you instrument to keep it in good operating condition. This section also includes information on using the
DAS to record diagnostic functions useful in predicting possible component failures before they happen.
10 THEORY OF OPERATION
An in-depth look at the various principals by which your analyzer operates as well as a description of how the various electronic, mechanical and pneumatic components of the instrument work and interact with each other. A close reading of this section is invaluable for understanding the instrument’s operation.
11 TROUBLESHOOTING
This section includes pointers and instructions for diagnosing problems with the instrument, such as excessive noise or drift, as well as instructions on performing repairs of the instrument’s major subsystems.
12. A PRIMER ON ELECTRO-STATIC DISCHARGE
Very important information on how static electricity occurs, why it is so dangerous to electronic components and assemblies as well as how to prevent that damage from occurring.
APPENDICES:
These include: software menu trees, warning messages, definitions of DAS & serial I/O variables, spare parts list, repair questionnaire, interconnect listing and drawings, and electronic schematics.
NOTE
Throughout this manual, words printed in capital, bold letters, such as SETUP or ENTR represent messages as they appear on the analyzer’s front panel display. Also, flowcharts in this manual contain typical representations of the analyzer’s display during the various operations being described. These representations are not intended to be exact and may differ slightly from the actual display of your instrument.
Teledyne Analytical Instruments 2
Introduction Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 3
Specifications Model GFC7000TA Carbon Dioxide Analyzer
2. SPECIFICATIONS AND APPROVALS
2.1. Specifications
GFC 7000TA Parameter
Ranges
(Physical Analog Output)
Measurement Units
Zero Noise
Span Noise
Lower Detectable Limit
Zero Drift (24 hours)
Span Drift (24 hours)
Lag Time
Rise/Fall Time
Linearity
Precision
Sample Flow Rate
Table 2-1: Model GFC 7000TA Basic Unit Specifications
Temperature Coefficient
Voltage Coefficient
AC Power Rating
Analog Output Ranges
Analog Output Resolution
Recorder Offset
Standard I/O
GFC 7000TA Specification
Min: 0-2 ppm Full scale
Max: 0-2,000 ppm Full scale
Selectable, dual ranges and auto ranging supported ppb, ppm, µg/m
3
, mg/m
3
, % (user selectable)
< 0.1 ppm (RMS)
< 1% of reading (RMS)
< 0.2 ppm
1
<0.25 ppm
1
<0.5% of reading
1
10 seconds
<60 seconds to 95%
1% of full scale
0.5% of reading
800cm
3
/min. ±10%
O
2
Sensor option adds 110 cm³/min, ±20%, to total flow through when installed.
< 0.1% of Full Scale per o C
< 0.05% of Full Scale per V
100V-120V, 220V – 240 V, 50/60 Hz
10V, 5V, 1V, 0.1V (selectable)
1 part in 4096 of selected full-scale voltage
Optional I/O
±10%
1 Ethernet: 10/100Base-T
2 RS-232 (300 – 115,200 baud)
2 USB device ports
8 opto-isolated digital status outputs
6 opto-isolated digital control inputs (3 defined, 3 spare)
4 analog outputs
1 USB com port
1 RS485
8 analog inputs (0-10V, 12-bit)
4 digital alarm outputs
Multidrop RS232
3 4-20mA current outputs
Temperature Range
Humidity Range
Dimensions H x W x D
5-40 o C
0 - 95% RH, non-condensing
7" x 17" x 23.5" (178 mm x 432 mm x 597 mm)
Teledyne Analytical Instruments 5
Specifications Model GFC7000TA Carbon Dioxide Analyzer
GFC 7000TA Parameter
Weight
GFC 7000TA Specification
40 lbs. (18.1 kg)
Certifications CE: EN61010-1:90 + A1:92 + A2:95, EN61326 - Class A
1
At constant temperature and voltage.
GFC 7000TM Parameter
Ranges
(Physical Analog Output)
Measurement Units
Zero Noise
Span Noise
Lower Detectable Limit
Zero Drift (24 hours)
Span Drift (24 hours)
Lag Time
Rise/Fall Time
Linearity
Precision
Sample Flow Rate
Temperature Coefficient
Voltage Coefficient
AC Power Requirements
Analog Output Ranges
Recorder Offset
Analog Output Resolution
Standard I/O
Optional I/O
Table 2-2: Model GFC 7000TM Basic Unit Specifications
Operating Temperature Range
Humidity Range
Dimensions H x W x D
Weight
GFC 7000TM Specification
Min: 0-4 ppm Full scale
Max: 0-4000 ppm Full scale
Selectable, dual ranges and auto ranging supported ppb, ppm, µg/m
3
, mg/m
3
, (selectable)
< 0.2 ppm (RMS)
< 1% of reading (RMS)
< 0.4 ppm
1
<0.5 ppm
1
<0.5% of reading 1
10 seconds
<60 seconds to 95%
1% of full scale
0.5% of reading
800cm
3
/min. ±10%
O
2
Sensor option adds 110 cm³/min, ±20%, to total flow though when installed
< 0.1% of Full Scale per o C or 0.1 ppm per o C, whichever is greater
< 0.05% of Full Scale per V
100V – 120V, 220V – 240V, 50/60 Hz
10V, 5V, 1V, 0.1V
±10%
1 part in 4096 of selected full-scale voltage
1 Ethernet: 10/100Base-T
2 RS232 (300-115,200 baud)
2 USB device ports
8 Status opto-isolated digital status outputs
6 Opto-isolated digital control inputs (3 defined, 3 spare)
4 Analog outputs
1 USB com port
1 RS485
8 Analog inputs (0-10V, 12-bit)
4 Digital alarm outputs
Multidrop RS232
3 4-20mA current outputs
5-40 o C
0 - 95% RH, non-condensing
7" x 17" x 23.5" (178 mm x 432 mm x 597 mm)
40 lbs. (18.1 kg)
Teledyne Analytical Instruments 6
Specifications Model GFC7000TA Carbon Dioxide Analyzer
GFC 7000TM Parameter GFC 7000TM Specification
Certifications
1 At constant temperature and voltage.
CE: EN61010-1:90 + A1:92 + A2:95, EN61326 - Class A
2.2. CE Mark Compliance
Emissions Compliance
The Teledyne Instruments Model GFC 7000TA Gas Filter Correlation CO
2 to be fully compliant with:
Analyzer was tested and found
EN61326 (1997 w/A1: 98) Class A, FCC Part 15 Subpart B section 15.107 Class A, ICES-003 Class A
(ANSI C63.4 1992) & AS/NZS 3548 (w/A1 & A2; 97) Class A.
Safety Compliance
The Teledyne Instruments Model GFC 7000TA Gas Filter Correlation CO
2 to be fully compliant with:
Analyzer was tested and found
IEC 61010-1:90 + A1:92 + A2:95
Teledyne Analytical Instruments 7
Getting Started
3. GETTING STARTED
Model GFC7000TA Carbon Dioxide Analyzer
3.1. Unpacking and Initial Set Up
CAUTION
To avoid personal injury, always use two persons to lift and carry the Model GFC
7000TA.
WARNING
Never disconnect PCAs, wiring harnesses or electronic subassemblies while the instrument is under power.
CAUTION – Avoid Warranty Invalidation
Printed circuit assemblies (PCAs) are sensitive to electro-static discharges too small to be felt by the human nervous system. Damage resulting from failure to use ESD protection when working with electronic assemblies will void the instrument warranty.
See A Primer on Electro-Static Discharge in this manual for more information on preventing ESD damage.
NOTE
It is recommended that you store shipping containers/materials for future use if/when the instrument should be returned to the factory for repair and/or calibration service. See Warranty section in this manual and shipping procedures on our
Website at: http://www.teledyne-api.com
under Customer Support > Return Authorization.
1. Verify that there is no apparent external shipping damage. If damage has occurred, please advise the shipper first, then Teledyne Instruments.
2. Included with your analyzer is a printed record of the final performance characterization performed on your instrument at the factory. This record, titled Final Test and Validation Data
Sheet (P/N 04596) is an important quality assurance and calibration record for this instrument. It should be placed in the quality records file for this instrument.
3. Carefully remove the top cover of the analyzer and check for internal shipping damage.
Remove the set-screw located in the top, center of the Front panel.
Remove the 2 screws fastening the top cover to the unit (one per side towards the rear).
Slide the cover backwards until it clears the analyzer’s front bezel.
Lift the cover straight up.
Teledyne Analytical Instruments 9
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
4. Inspect the interior of the instrument to make sure all circuit boards and other components are in good shape and properly seated.
5. Check the connectors of the various internal wiring harnesses and pneumatic hoses to make sure they are firmly and properly seated.
6. Verify that all of the optional hardware ordered with the unit has been installed. These are listed on the paperwork accompanying the analyzer.
VENTILATION CLEARANCE : Whether the analyzer is set up on a bench or installed into an instrument rack, be sure to leave sufficient ventilation clearance.
AREA
Back of the instrument
Sides of the instrument
Above and below the instrument
MINIMUM REQUIRED CLEARANCE
4 in.
1 in.
1 in.
Various rack mount kits are available for this analyzer. See Section 5.1 of this manual for more information.
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Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.2. Front Panel
Figure 3-1 shows the analyzer’s front panel layout, followed by a close-up of the display screen in Figure
3-2, which is described in Table 3-1. The two USB ports on the front panel are provided for the connection of peripheral devices:
plug-in mouse (not included) to be used as an alternative to the touchscreen interface
thumb drive (not included) to download updates to instruction software (contact TAI Customer
Service for information).
Figure 3-1: Front Panel Layout
Teledyne Analytical Instruments 11
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Figure 3-2: Display Screen and Touch Control
CAUTION – Avoid Damaging Touchscreen
Do not use hard-surfaced instruments such as pens to operate the touchscreen.
The front panel liquid crystal display includes touch control. Upon analyzer start-up, the display shows a splash screen and other initialization indicators before the main display appears, similar to Figure 3-2 above (may or may not display a Fault alarm). The LEDs on the display screen indicate the Sample,
Calibration and Fault states; also on the screen is the gas concentration field (Conc), which displays realtime readouts for the primary gas and for the secondary gas if installed. The display screen also shows which mode the analyzer is currently in (Mode field), as well as messages and data (Param field). Along the bottom of the screen is a row of touch control buttons; only those that are currently applicable will have a label. Table 3-1 provides detailed information for each component of the screen.
Teledyne Analytical Instruments 12
Getting Started
Field
Status
Model GFC7000TA Carbon Dioxide Analyzer
Table 3-1: Display and Touchscreen Control Description
Description/Function
LEDs indicating the states of Sample, Calibration and Fault, as follows:
Conc
Mode
Param
SAMPLE Green
Off
On
Blinking
Unit is not operating in sample mode, DAS is disabled.
Sample Mode active; Front Panel Display being updated; DAS data being stored.
Unit is operating in sample mode, front panel display being updated,
DAS hold-off mode is ON, DAS disabled
Off
Blinking
FAULT Red
Off
Blinking
Auto Cal disabled
Auto Cal enabled
Unit is in calibration mode
No warnings exist
Warnings exist
Displays the actual concentration of the sample gas currently being measured by the analyzer in the currently selected units of measure
Displays the name of the analyzer’s current operating mode
Displays a variety of informational messages such as warning messages, operational data, test function values and response messages during interactive tasks.
Control Buttons Displays dynamic, context sensitive labels on each button, which is blank when inactive until applicable.
Figure 3-3 shows how the front panel display is mapped to the menu charts illustrated in this manual. The
Mode, Param (parameters), and Conc (gas concentration) fields in the display screen are represented across the top row of each menu chart. The eight touchscreen control buttons along the bottom of the display screen are represented in the bottom row of each menu chart.
Teledyne Analytical Instruments 13
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Figure 3-3: Display/Touch Control Screen Mapped to Menu Charts
Teledyne Analytical Instruments 14
Getting Started
3.3. Rear Panel
Model GFC7000TA Carbon Dioxide Analyzer
Figure 3-4: Rear Panel Layout
Table 3-2 provides a description of each component on the rear panel
Teledyne Analytical Instruments 15
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Table 3-2: Rear Panel Description
Component Function cooling fan
Pulls ambient air into chassis through side vents and exhausts through rear
Connector for three-prong cord to apply AC power to the analyzer
AC power connector
CAUTION! The cord’s power specifications (specs) MUST comply with the power specs on the analyzer’s rear panel Model number label
Model/specs label
Identifies the analyzer model number and provides power specs
PURGE IN
SAMPLE
EXHAUST
VENT SPAN
PRESSURE SPAN
Connect a gas line from the source of sample gas here
Calibration gases are also inlet here on units without zero/span valve options installed
Connect an exhaust gas line of not more than 10 meters long here that leads outside the shelter or immediate area surrounding the instrument
Span gas vent outlet for units with zero/span valve options installed
Connect an exhaust gas line of not more than 10 meters long here
On units with zero/span valve options installed, connect a gas line to the source of calibrated span gas here
IZS
Internal Zero Air: On units with zero/span valve options installed but no internal zero air scrubber attach a gas line to the source of zero air here
RX TX
LEDs indicate receive (RX) and transmit (TX) activity on the when blinking
COM 2
Serial communications port for RS-232 or RS-485
RS-232
Serial communications port for RS-232 only
DCE DTE
Switch to select either data terminal equipment or data communication equipment during RS-232 communication
STATUS
For outputs to devices such as Programmable Logic Controllers (PLCs)
ANALOG OUT
For voltage or current loop outputs to a strip chart recorder and/or a data logger
CONTROL IN
For remotely activating the zero and span calibration modes
ALARM
Option for concentration alarms and system warnings
ETHERNET
Connector for network or Internet remote communication, using Ethernet cable
ANALOG IN
Option for external voltage signals from other instrumentation and for logging these signals
USB
Com port optional connector for direct connection to laptop computer, using USB cable
Information Label
Includes voltage and frequency specifications
Teledyne Analytical Instruments 16
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.4. Internal Layout
Figure 3-3 shows a top-down view of the analyzer. The shown configuration includes the Ethernet board,
IZS option, zero-air scrubber and an additional sample dryer. See Section 5 for optional equipment.
Figure 3-5: Internal Chassis Layout
Teledyne Analytical Instruments 17
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Sample Gas Flow
Sensor
Sample Gas Outlet fitting
Sample Chamber
Sync/Demod PCA
Housing
Opto-Pickup
PCA
Pressure Sensor(s)
GFC Wheel
Heat Sync
IR Source
Bench
Temperature
Thermistor
Shock Absorbing
Mounting Bracket
Purge Gas
Pressure Regulator
GFC Wheel Motor
GFC Temperature
Sensor
GFC Heater
Purge Gas
Inlet
Figure 3-6: Optical Bench Layout
Teledyne Analytical Instruments 18
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Figure 3-7: GFC 7000TA Internal Gas Flow
3.5. Electrical Connections
WARNING
Never disconnect PCAs, wiring harnesses or electronic subassemblies while the instrument is under power.
NOTE
To maintain compliance with EMC standards, it is required that the cable length be no greater than 3 meters for all I/O connections, which include Analog In, Analog Out, Status Out, Control In, Ethernet/LAN,
USB, RS-232, and RS-485.
Refer to Figure 3-4 for the locations of the rear panel connections.
Teledyne Analytical Instruments 19
Getting Started
3.5.1. Power Connection
Model GFC7000TA Carbon Dioxide Analyzer
WARNING
Power connection must have functioning ground connection.
Do not defeat the ground wire on power plug.
Turn off analyzer power before disconnecting or connecting electrical subassemblies.
Do not operate with cover off.
CAUTION
Check the voltage and frequency specifications on the rear panel Model Label for compatibility with the local power before plugging the analyzer into line power.
Do not plug in the power cord if the voltage or frequency is incorrect.
The GFC 7000TA analyzer can be configured for both 100-130 V and 210-240 V at either 50 or 60 Hz.
To avoid damage to your analyzer, make sure that the AC power voltage matches the voltage indicated on the rear panel serial number label and that the frequency is between 47 and 63 Hz.
Attach the power cord to the analyzer and plug it into a power outlet capable of carrying at least 10 A current at your AC voltage and that it is equipped with a functioning earth ground.
3.5.2. Connecting Analog Inputs (Option 64)
The Analog In connector is used for connecting external voltage signals from other instrumentation (such as meteorological instruments) and for logging these signals in the analyzer’s internal DAS. The input voltage range for each analog input is 0-10 VDC.
Figure 3-8: Analog In Connector
Teledyne Analytical Instruments 20
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Pin assignments for the Analog In connector are presented in Table 3-3.
Table 3-3: Analog Input Pin Assignments
5
6
3
4
1
2
PIN DESCRIPTION DAS
PARAMETER
1
Analog input # 1
Analog input # 2
AIN 1
AIN 2
Analog input # 3
Analog input # 4
Analog input # 5
Analog input # 6
AIN 3
AIN 4
AIN 5
AIN 6
7
8
Analog input # 7
Analog input # 8
AIN 7
AIN 8
GND Analog input Ground N/A
1 See Section 6.7 for details on setting up the DAS.
3.5.3. Connecting Analog Outputs
The GFC 7000TA is equipped with several analog output channels accessible through a connector on the back panel of the instrument. The standard configuration for these outputs is mVDC. An optional current loop output is available for each.
When the instrument is in its default configuration, channels A1 and A2 output a signal that is proportional to the CO
2
concentration of the sample gas. Either can be used for connecting the analog output signal to a chart recorder or for interfacing with a data logger.
Output A3 is only used if the optional O
2
sensor is installed.
Channel A4 is special. It can be set by the user (see Section 6.13.9) to output any one of the parameters accessible through the <TST TST> keys of the units sample display.
To access these signals attach a strip chart recorder and/or data-logger to the appropriate analog output connections on the rear panel of the analyzer.
ANALOG
A1 A2 A3 A4
1 2 3 4 5 6 7 8
Pin-outs for the analog output connector at the rear panel of the instrument are:
Teledyne Analytical Instruments 21
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
PIN
1
2
3
4
5
6
7
Table 3-4: GFC 7000TA Analog Output Pin Outs
ANALOG OUTPUT
A1
A2
VDC SIGNAL
V Out
Ground
V Out
Ground
V Out
A3
(Only used if O
2
sensor is installed)
Ground
MADC SIGNAL
I Out +
I Out -
I Out +
I Out -
I Out +
I Out -
A4
V Out Not used
The default analog output voltage setting of the GFC 7000TA CO
2 a range of 0 – 500 ppm.
Analyzer is 0 – 5 VDC with
TO change these settings, see Sections 6.13.4 and 6.8 respectively.
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Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.5.4. Connecting the Status Outputs
If you wish utilize the analyzer’s status outputs to interface with a device that accepts logic-level digital inputs, such as programmable logic controllers (PLC’s) they are accessed via a 12-pin connector on the analyzer’s rear panel labeled STATUS.
STATUS
1 2 3 4 5 6 7 8 D +
NOTE
Most PLC’s have internal provisions for limiting the current the input will draw.
When connecting to a unit that does not have this feature, external resistors must be used to limit the current through the individual transistor outputs to ≤50mA
(120 Ω for 5V supply).
OUTPUT #
1
2
8
D
+
3
4
5
6
7
The pin assignments for the status outputs can be found in the table below:
Table 3-5: Status Output Pin-outs
STATUS
DEFINITION
CONDITION
SYSTEM OK
CONC VALID
HIGH RANGE
ZERO CAL
SPAN CAL
DIAG MODE
ALARM1
On if no faults are present.
On if CO
2
concentration measurement is valid.
If the CO
2
concentration measurement is invalid, this bit is OFF.
On if unit is in high range of DUAL or AUTO range modes.
On whenever the instruments ZERO point is being calibrated.
On whenever the instruments SPAN point is being calibrated.
On whenever the instrument is in DIAGNOSTIC mode.
On whenever the measured CO
2
concentration is above the set point for
ALM1
ALARM2
On whenever the measured CO
2
concentration is above the set point for
ALM2
EMITTER BUS The emitters of the transistors on pins 1-8 are bused together.
DC POWER + 5 VDC
Digital Ground The ground level from the analyzer’s internal DC power supplies.
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Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.5.5. Connecting the Control Inputs
If you wish to use the analyzer to remotely activate the zero and span calibration modes, several digital control inputs are provided through a 10-pin connector labeled CONTROL IN on the analyzer’s rear panel.
There are two methods for energizing the control inputs. The internal +5V available from the pin labeled
“+” is the most convenient method. However, if full isolation is required, an external 5 VDC power supply should be used.
CONTROL IN CONTROL IN
A B C D E F U +
Z
E
R
O
S
P
A
N
A B C D E F U +
Z
E
R
O
S
P
A
N
-
5 VDC Power
Supply
+
Local Power Connections External Power Connections
The pin assignments for the digital control inputs can be found in the table below:
INPUT #
A
B
C
D
E
F
U
+
Table 3-6: Control Input Pin-outs
STATUS
DEFINITION
REMOTE ZERO
CAL
REMOTE
SPAN CAL
ON CONDITION
The Analyzer is placed in Zero Calibration mode. The mode field of the display will read ZERO CAL R.
The Analyzer is placed in Span Calibration mode. The mode field of the display will read SPAN CAL R.
SPARE
SPARE
SPARE
SPARE
Digital Ground May be connected to the ground of the data logger/recorder.
Pull-up supply for inputs
Internal +5V
Supply
Input pin for +5 VDC required to activate pins A – F. This can be from an external source or from the “+” pin of the instruments STATUS connector.
Internal source of +5V which can be used to actuate control inputs when connected to the U pin.
Teledyne Analytical Instruments 24
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.5.6. Connecting the Communications Interfaces
For RS-232 or RS-485 communications through the analyzer’s serial interface com ports, refer to Section
6.11 of this manual for instructions on their configuration and usage.
3.5.6.1. Connecting to a LAN or the Internet
For network or Internet communication with the analyzer, connect an Ethernet cable from the analyzer’s rear panel Ethernet interface connector to an Ethernet access port.
NOTE:
The GFC 7000TA firmware supports dynamic IP addressing or DHCP.
If your network also supports DHCP, the analyzer will automatically configure its
LAN connection appropriately,
If your network does not support DHCP, see Section 6.11.6.3 for instructions on manually configuring the LAN connection.
3.5.6.2. Connecting to a Personal Computer (PC)
If the analyzer is configured with the USB com option, connect a USB cable between the USB ports of the analyzer’s rear panel and a desktop or laptop PC for direct communication between the two. Their baud rates must match (see Section 6.11.8).
3.5.6.3. Connecting to a Multidrop Network
If your unit has a Teledyne Instruments RS-232 multidrop card (Option 62), see Section 6.11.7 for instructions on setting it up.
3.6. Pneumatic Connections
CAUTION!
Do not operate this instrument until you’ve removed dust plugs from SAMPLE and EXHAUST ports on the rear panel!
Teledyne Analytical Instruments 25
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.6.1. Basic Pneumatic Connections
NOTE
In order to prevent dust from getting into the gas flow channels of your analyzer, it was shipped with small plugs inserted into each of the pneumatic fittings on the back panel. Remove these plugs before operating the analyzer. It is recommended that they be stored for future use (moving, storing or shipping the analyzer).
Figure 3-4 illustrates the basic configuration for gas supply and exhaust lines to the Model GFC 7000TA
Analyzer. Figure 3-5 illustrates the internal gas flow of the instrument in its basic configuration.
Please refer to Figure 3-2 for pneumatic connections at the rear panel and Table 3-2 for description.
NOTE
Sample and calibration gases should only come into contact with PTFE (Teflon),
FEP, glass, stainless steel or brass.
REAR PANEL LABEL
SAMPLE
EXHAUST
PRESSURE SPAN
VENT SPAN
IZS
PURGE IN
Table 3-7: Rear Panel Pneumatic Connections
FUNCTION
Connect a gas line from the source of sample gas here.
Calibration gasses are also inlet here on units without zero/span valve or IZS options installed.
Connect an exhaust gas line of not more than 10 meters long here.
On units with zero/span valve options installed, connect a gas line to the source of calibrated span gas here.
Span gas vent outlet for units with zero/span valve options installed.
Connect an exhaust gas line of not more than 10 meters long here.
Internal zero air scrubber.
On units with zero/span valve options installed but no internal zero air scrubber, attach a gas line to the source of zero air here.
This inlet supplies purge air to the GFC wheel housing (see Section 10.2.3)
Connect a source of dried air that has been scrubbed of CO
2
.
Teledyne Analytical Instruments 26
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Figure 3-9: Pneumatic Connections–Basic Configuration–Using Bottled Span Gas
Figure 3-10: Pneumatic Connections–Basic Configuration–Using Gas Dilution Calibrator
Teledyne Analytical Instruments 27
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
7. Attach a sample inlet line to the sample inlet port. The SAMPLE input line should not be more than 2 meters long.
NOTE
Ideally, the pressure of the sample gas should be at ambient pressure (0 psig).
Maximum pressure of sample gas should not exceed 1.5 in-Hg over ambient.
In applications where the sample gas is received from a pressurized manifold, a vent must be placed as shown to equalize the sample gas with ambient atmospheric pressure before it enters the analyzer.
This vent line must be:
At least 0.2m long
No more than 2m long and vented outside the shelter or immediate area surrounding the instrument.
8. Attach sources of zero air and span gas (see Figures 3-3 through 3-8 inclusive).
Span Gas is a gas specifically mixed to match the chemical composition of the type of gas being measured at near full scale of the desired measurement range.
In the case of CO
2
measurements made with the Teledyne Instruments Model GFC 7000TA
Analyzer it is recommended that you use a gas calibrated to have a CO
2
content equaling
80% of the range of compositions being measured.
EXAMPLE: If the application is to measure between 0 ppm and 500 ppm, an appropriate Span
Gas would be 400 ppm. If the application is to measure between 0 ppm and 100 ppm, an appropriate Span Gas would be 80 ppm.
Span Gas can be purchased in pressurized canisters or created using Dynamic Dilution
Calibrator such as the Teledyne Instruments Model T700 and a source of dried air scrubbed of CO
2
such as a bottle of N
2
.
Zero Air is similar in chemical composition to the Earth’s atmosphere but scrubbed of all components that might affect the analyzer’s readings.
In the case of CO
2
measurements this means less than 0.1 ppm of CO
2
and Water Vapor
(when dew point <-15˚C). Zero Air can be purchased in pressurized canisters.
9. Attach an exhaust line to the exhaust outlet port.
The exhaust from the pump and vent lines should be vented to atmospheric pressure using maximum of 10 meters of ¼” PTEF tubing.
CAUTION
Venting should be outside the shelter or immediate area surrounding the instrument.
Teledyne Analytical Instruments 28
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
10. Attach a source of dried air scrubbed of CO
2
to the purge inlet port.
NOTE
The minimum gas pressure of the source of purge air should be 7.5 psig.
If the source of the purge air is shared by a Teledyne Instruments T700 (as shown in figure 3-7) the minimum gas pressure should be 25 psig and should not exceed
35 psig.
11. Once the appropriate pneumatic connections have been made, check all pneumatic fittings for leaks using a procedure similar to that defined in Section 9.3.3.
Teledyne Analytical Instruments 29
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.6.2. Connections with Internal Valve Options Installed
Figure 3-11 and Figure 3-12 show the pneumatic connections for the ambient zero and ambient span valve option (Option 50A).
Figure 3-11: Pneumatic Connections with Ambient Zero/Ambient Span Valves (OPT 50A)
Figure 3-12: Pneumatic Connections with Ambient Zero/Ambient Span Valves (Opt 50A) and
External Zero Air Scrubber
Teledyne Analytical Instruments 30
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Figure 3-13 and Figure 3-14 show the pneumatic connections for the ambient zero and ambient span valve option (Option 50B).
Figure 3-13: Pneumatic Connections with Ambient Zero/Pressurized Span Valves (OPT 50B)
Figure 3-14: Pneumatic Connections with Ambient Zero/Pressurized Span Valves (Opt 50B) and
External Zero Air Scrubber
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Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.6.3. Pneumatic Connections in Multipoint Calibration Applications
Some applications may require multipoint calibration checks where span gas of several different concentrations is needed. We recommend using high-concentration, certified, calibration gas supplied to the analyzer through a Gas Dilution Calibrator such as a Teledyne Instruments Model T700. This type of calibrator precisely mixes Span Gas and Zero Air to produce any concentration level between 0 ppm and the concentration of the calibrated gas.
Figure 3-12 depicts the pneumatic set up in this sort of application of a Model GFC 7000TA CO application).
2
Analyzer with ambient zero/ambient span valve option 50A installed (a common configuration for this type of
Figure 3-15: Example of Pneumatic Set up for Multipoint Calibration
3.6.4. Setting the Internal Purge Air Pressure
In order to maintain proper purge air flow though the GFC wheel housing, a manually adjustable pressure regulator is provided (see Figure 3-5). This regulator includes two output ports. One is used to supply purge air to the GFC wheel. The other may be used to attach a pressure gauge.
To adjust the internal purge air pressure of the GFC 7000TA:
1. Turn off the instrument.
2. Remove the source of zero air attached to the purge line inlet port at the back of the analyzer.
3. Remove the analyzer’s top cover.
4. Remove the cap from the second, unused, output port on the pressure regulator.
5. Attach a pressure gauge capable of measuring in the 5-10 psig range with 0.5 psig resolution to the port.
Teledyne Analytical Instruments 32
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
6. Turn the instrument on.
7. Make sure the zero air supply to the analyzer’s purge line inlet is supplying gas at a stable pressure above 7.5 psig.
8. Adjust the GFC 7000TA’s pressure regulator until the attached gauge reads 7.5 psig.
9. Turn off the instrument.
10. Remove the source of zero air attached to the purge line inlet port at the back of the analyzer.
11. Remove the pressure gauge and reattach the end cap removed in step 4 above.
12. Replace the analyzer’s top cover.
3.7. Initial Operation
If you are unfamiliar with the GFC 7000TA theory of operation, we recommend that you read
Section 10. For information on navigating the analyzer’s software menus, see the menu trees described in Appendix A.
NOTE
The analyzer’s cover must be installed to ensure that the temperatures of the GFC wheel and absorption cell assemblies are properly controlled.
3.7.1. Startup
After electrical and pneumatic connections are made, and initial functional check is required. Turn on the instrument. The pump, exhaust fan and PMT cooler fan should start immediately. The display will briefly show a logo splash screen at the start of initialization.
The analyzer should automatically switch to Sample Mode after completing the boot-up sequence and start monitoring CO
2
gas. However, there is an approximately one hour warm-up period before reliable gas measurements can be taken. During the warm-up period, the front panel display may show messages in the Parameters field.
Teledyne Analytical Instruments 33
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.7.2. Warm Up
During the warm-up period various portions of the instrument’s front panel may behave as indicated in
Table 3-8.
NAME
Conc field
Mode field
Param field
STATUS LEDs
N/A
N/A
N/A
Table 3-8: Front Panel Display During System Warm-Up
COLOR BEHAVIOR
Displays current, compensated CO
2
Concentration
Displays current mode, e.g.,
SAMPLE”
Displays menu items and messages.
This is normal operation, but deemed inaccurate during the warm-up period.
SIGNIFICANCE
Instrument is in Sample mode but is still in the process of warming up. (DAS holdoff period is active)
Refer to Table 3-9 for a list and descriptions of warning messages.
Cal Yellow Off
Unit is operating in sample mode; front panel display is being updated.
Flashes On/Off when adaptive filter is active
The instrument’s calibration is not enabled.
The analyzer is warming up and hence out of specification for a fault-free reading. Various warning messages appear in the Param field.
3.7.3. Warning Messages
Because internal temperatures and other conditions may be outside be specified limits during the analyzer’s warm-up period, the software will suppress most warning conditions for 30 minutes after power up. If warning messages persist after the 30 minutes warm up period is over, investigate their cause using the troubleshooting guidelines in Section 11 of this manual.
To view and clear warning messages, press:
TEST deactivates warning messages
SAMPLE HVPS WARNING CO2 = 0.00
TEST CAL MSG CLR SETUP
SAMPLE
< TST TST > CAL
RANGE=500.000 PPM CO2 = 0.00
MSG
CLR SETUP
MSG activates warning messages.
<TST TST > keys replaced with
TEST key
NOTE:
If the warning message persists after several attempts to clear it, the message may indicate a real problem and not an artifact of the warm-up period
SAMPLE
TEST CAL
HVPS WARNING
MSG
CO2 = 0.00
CLR SETUP
Make sure warning messages are not due to real problems.
Press CLR to clear the current message.
If more than one warning is active, the next message will take its place
Once the last warning has been cleared, the analyzer returns to
SAMPLE mode
Table 3-6 lists brief descriptions of the warning messages that may occur during start up.
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Getting Started Model GFC7000TA Carbon Dioxide Analyzer
Table 3-9: Possible Warning Messages at Start-Up
MESSAGE MEANING
ANALOG CAL WARNING The instrument’s A/D circuitry or one of its analog outputs is not calibrated.
BENCH TEMP WARNING The optical bench Temperature is outside the specified limits.
BOX TEMP WARNING Remote span calibration failed while the dynamic span feature was set to turned on.
CANNOT DYN SPAN Remote zero calibration failed while the dynamic zero feature was set to turned on.
CANNOT DYN ZERO Configuration was reset to factory defaults or was erased.
CONC ALRM1 WARNING Concentration alarm 1 is enabled and the measured CO
2
level is ≥ the set point.
CONC ALRM2 WARNING Concentration alarm 2 is enabled and the measured CO
2
level is ≥ the set point.
CONFIG INITIALIZED Configuration storage was reset to factory configuration or erased.
DATA INITIALIZED DAS data storage was erased.
O2 CELL TEMP WARN O
2
sensor cell temperature outside of warning limits.
PHOTO TEMP WARNING The temperature of the IR photometer is outside the specified limits.
REAR BOARD NOT DET The CPU is unable to communicate with the motherboard.
RELAY BOARD WARN The firmware is unable to communicate with the relay board.
The flow rate of the sample gas is outside the specified limits. SAMPLE FLOW WARN
SAMPLE PRESS WARN Sample gas pressure outside of operational parameters.
The temperature of the sample gas is outside the specified limits. SAMPLE TEMP WARN
SOURCE WARNING The IR source may be faulty.
The computer was rebooted. SYSTEM RESET
WHEEL TEMP WARNING The Gas Filter Correlation wheel temperature is outside the specified limits.
Teledyne Analytical Instruments 35
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.7.4. Functional Check
1. After the analyzer’s components has warmed up for at least 30 minutes, verify that the software properly supports any hardware options that were installed.
2. Check to make sure that the analyzer is functioning within allowable operating parameters.
Appendix C includes a list of test functions viewable from the analyzer’s front panel as well as their expected values. These functions are also useful tools for diagnosing performance problems with your analyzer (Section11.1.2). The enclosed Final Test and Validation Data sheet
(part number 04307) lists these values before the instrument left the factory.
To view the current values of these parameters press the following button sequence on the analyzer’s front panel. Remember until the unit has completed its warm up these parameters may not have stabilized.
SAMPLE RANGE = 500.000 PPM CO2 = XXX.X
< TST TST > CAL SETUP
Toggle <TST TST> buttons to scroll through list of
1 Only appears instrument is set for DUAL or AUTO reporting range modes.
2
Only appears if O
2
Sensor
Option is installed.
RANGE
RANGE1
1
RANGE2
O
2
1
RANGE
2
STABIL
MEAS
REF
MR RATIO
PRES
SAMP FL
SAMP TEMP
BENCH TEMP
WHEEL TEMP
BOX TEMP
PHT DRIVE
SLOPE
OFFSET
TEST
TIME
Refer to
Table 6-2 for definitions of these test functions.
If your network is running a dynamic host configuration protocol (DHCP) software package, the
Ethernet feature will automatically configure its interface with your LAN. (See Section 6.11.6.2).
This configuration is useful for quickly getting an instrument up and running on a network.
However, for permanent Ethernet connections, a static IP address should be used. (See Section
6.11.6.3).
Teledyne Analytical Instruments 36
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.8. Initial Calibration Procedure
The next task is to calibrate the analyzer.
To perform the following calibration you must have sources for zero air and span gas available for input into the sample port on the back of the analyzer. See Section 3.1.3 for instructions for connecting these gas sources.
While it is possible to perform this procedure with any range setting we recommend that you perform this initial checkout using the 500 ppm range.
NOTE
The following procedure assumes that the instrument does not have any of the available
Zero/Span Valve Options installed.
See Section 7.4 for instructions for calibrating instruments possessing Z/S valve options.
1. Set the Analog Output Range:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X RANGE CONTROL MENU
MODE SET UNIT EXIT
Press this button to set the analyzer for SNGL
DUAL or AUTO ranges
Press this button to select the concentration units of measure:
PPB, PPM, UGM, MGM
To change the value of the reporting range span, enter the number by pressing the key under each digit until the expected value appears.
SETUP X.X RANGE: 500.000 CONC
0 0 5 0 0 .
0 ENTR EXIT
SETUP X.X
RANGE: 500.000 Conc
0 0 0 5 0 .0 ENTR EXIT
EXIT ignores the new setting and returns to the RANGE CONTROL
MENU .
ENTR accepts the new setting and returns to the
RANGE CONTROL MENU .
Teledyne Analytical Instruments 37
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
2. Set the expected CO
2
span gas concentration
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP This sequence causes the analyzer to prompt for the expected CO
2
span concentration.
M-P CAL RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > ZERO CONC EXIT
The CO
2
span concentration values automatically default to
400.0 Conc .
To change this value to the actual concentration of the span gas, enter the number by pressing the button under each digit until the expected value appears.
M-P CAL CO2 SPAN CONC: 400.000 Conc
0 0 0 4 5 .0
ENTR EXIT
EXIT ignores the new setting and returns to the previous display.
ENTR accepts the new setting and returns to the previous display..
NOTE
For this Initial Calibration it is important to independently verify the precise CO
2
Concentration Value of the SPAN gas.
If the source of the Span Gas is from a Calibrated Bottle, use the exact concentration value printed on the bottle.
Teledyne Analytical Instruments 38
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3. Perform the Zero/Span Calibration Procedure
SAMPLE* RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > CAL SETUP
Set the Display to show the
STABIL test function.
This function calculates the stability of the CO x measurement
SAMPLE STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL SETUP
ACTION:
Allow zero gas to enter the sample port at the rear of the instrument.
Wait until STABIL falls below 1.0 ppm.
This may take several minutes.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL SETUP
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > ZERO CONC EXIT
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > ENTR CONC EXIT
Press ENTR to changes the
OFFSET & SLOPE values for the
CO
2
measurements.
Press EXIT to leave the calibration unchanged and return to the previous menu.
ACTION:
Allow span gas to enter the sample port at the rear of the instrument.
The value of
STABIL may jump significantly.
Wait until it falls back below 1.0 ppm
This may take several minutes. The SPAN button now appears during the transition from zero to span..
If either the ZERO or
SPAN buttons fail to appear see Section 11 for troubleshooting tips.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > SPAN CONC EXIT
M-P CAL RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ENTR SPAN CONC EXIT
M-P CAL RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ENTR CONC EXIT
Press ENTR to change the
OFFSET & SLOPE values for the
CO
2
measurements.
Press EXIT to leave the calibration unchanged and return to the previous menu.
EXIT returns to the main
SAMPLE display
Teledyne Analytical Instruments 39
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
3.8.1. Initial O
2
Sensor Calibration Procedure
If your instrument has an O
2
sensor option installed that should be calibrated as well.
3.8.1.1. O
2
Calibration Setup
The pneumatic connections for calibrating are as follows:
Figure 3-16: O2 Sensor Calibration Set Up
O
2
SENSOR ZERO GAS: Teledyne Instruments’ recommends using pure N
2 point of your O
2
sensor option.
when calibration the zero
O
2
SENSOR SPAN GAS: Teledyne Instruments’ recommends using 21% O
2 span point of your O
2
sensor option.
in N
2
when calibration the
3.8.1.2. O
2
Calibration Method
STEP 1 – SET O
2
SPAN GAS CONCENTRATION :
Set the expected O
2
span gas concentration.
This should be equal to the percent concentration of the O
2
(default factory setting = 20.8%; the approximate O
2
span gas of the selected reporting range
content of ambient air).
Teledyne Analytical Instruments 40
Getting Started
SAMPLE RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > CAL SETUP
Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE
CO2 O2
GAS TO CAL:CO2
ENTR EXIT
M-P CAL A1:NXCNC1 =100PPM NOX=X.XXX
<TST TST> ZERO SPAN CONC EXIT
SAMPLE
NOX O2
GAS TO CAL:O2
ENTR EXIT
The O
2
span concentration value automatically defaults to
20.8 % .
If this is not the the concentration of the span gas being used, toggle these buttons to set the correct concentration of the O
2
calibration gases.
M-P CAL O2 SPAN CONC:20.8%
0 2 0 .8
0 ENTR EXIT
EXIT ignores the new setting and returns to the previous display.
ENTR accepts the new setting and returns to the previous menu.
STEP 2 – ACTIVATE O
2
SENSOR STABILITY FUNCTION
To change the stability test function from NO x
concentration to the O
2
sensor output, press:
Teledyne Analytical Instruments 41
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X ENTER PASSWORD:818
8 1 8 ENTR
EXIT
SETUP X.X 0) DAS_HOLD_OFF=15.0 Minutes
<PREV NEXT> JUMP EDIT PRNT EXIT
Continue pressing NEXT until ...
SETUP X.X 2) STABIL_GAS=CO2
<PREV NEXT> JUMP
EDIT
PRNT EXIT
SETUP X.X STABIL_GAS:CO2
CO2 O2 ENTR EXIT
SETUP X.X
STABIL_GAS:O2
CO2 O2 ENTR EXIT
Press EXIT 3 times to return to SAMPLE menu
NOTE
Use the same procedure to reset the STB test function to CO
2 calibration procedure is complete.
when the O
2
Teledyne Analytical Instruments 42
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
STEP 4 – O
2
Zero/Span Calibration perform by pressing:
The Model GFC 7000TA Analyzer is now ready for operation.
Teledyne Analytical Instruments 43
Getting Started Model GFC7000TA Carbon Dioxide Analyzer
NOTE
Once you have completed the above set-up procedures, please fill out the Quality
Questionnaire that was shipped with your unit and return it to Teledyne
Instruments.
This information is vital to our efforts in continuously improving our service and our products.
THANK YOU.
Teledyne Analytical Instruments 44
FAQ Model GFC7000TA Carbon Dioxide Analyzer
4. FREQUENTLY ASKED QUESTIONS
4.1. FAQ’s
The following is a list from the Teledyne Instruments’ Customer Service Department of the most commonly asked questions relating to the Model CO
2
Analyzer.
Q: How do I get the instrument to zero / Why is the zero key not displayed?
A: See Section 11.3.4 Inability to zero.
Q: How do I get the instrument to span / Why is the span key not displayed?
A: See Section 11.3.3 Inability to span.
Q: Why does the ENTR key sometimes disappear on the Front Panel Display?
A: During certain types of adjustments or configuration operations, the ENTR key will disappear if you select a setting that is nonsensical (such as trying to set the 24-hour clock to 25:00:00) or out of the allowable range for that parameter (such as selecting a DAS Holdoff period of more than 20 minutes).
Once you adjust the setting in question to an allowable value, the ENTR key will re-appear.
Q: Is there an optional midpoint calibration?
A: There is an optional mid point linearity adjustment; however, midpoint adjustment is applicable only to applications where CO
2
measurements are expected above 100 ppm. Call Teledyne Instruments’
Service Department for more information on this topic.
Q: How do I make the display and data logger analog input agree?
A: This most commonly occurs when an independent metering device is used besides the data logger/recorded to determine gas concentration levels while calibrating the analyzer. These disagreements result from the analyzer, the metering device and the data logger having slightly different ground levels.
Both the electronic scale and offset of the analog outputs can be adjusted (see Section 6.13.4.3).
Alternately, use the data logger itself as the metering device during calibrations procedures.
Q: How do I perform a leak check?
A: See Section 9.3.3.
Q: How do I measure the sample flow?
A: Sample flow is measured by attaching a calibrated rotameter, wet test meter, or other flowmeasuring device to the sample inlet port when the instrument is operating. The sample flow should be 800 cm
3
/min 10%. See Section 9.3.4.
Q: How long does the IR source last?
A: Typical lifetime is about 2-3 years.
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Q: Where is the sintered filter/sample flow control orifice?
A: These components are located inside the flow control assembly that is attached to the inlet side of the sample pump, see Figure 3-3. See Section 11.6.1 for instructions on disassembly and replacement.
Q: How do I set up a SEQUENCE to run a nightly calibration check?
A: The setup of this option is located in Section 7.6.
Q: How do I set the analog output signal range and offset?
A: Instructions for this can be found in Section 6.13.4 which describes analog I/O configuration.
Q: What is the averaging time for an GFC 7000TA?
A: The default averaging time, optimized for ambient pollution monitoring, is 150 seconds for stable concentrations and 10 seconds for rapidly changing concentrations; See Section10.5.1 for more information. However, it is adjustable over a range of 0.5 second to 200 seconds (please contact customer service for more information).
4.2. Glossary
Note: Some terms in this glossary may not occur elsewhere in this manual.
Term Description/Definition
10BaseT
100BaseT
APICOM
ASSY an Ethernet standard that uses twisted (“T”) pairs of copper wires to transmit at
10 megabits per second (Mbps) same as 10BaseT except ten times faster (100 Mbps) name of a remote control program offered by Teledyne to its customers
Assembly
CAS
CD
CE
Code-Activated Switch
Corona Discharge , a frequently luminous discharge, at the surface of a conductor or between two conductors of the same transmission line, accompanied by ionization of the surrounding atmosphere and often by a power loss
Converter Efficiency , the percentage of light energy that is actually converted into electricity
CEM Continuous Emission Monitoring
Chemical formulas that may be included in this document:
CO
2 carbon dioxide
C
3
H
8
propane
CH
4
methane
H
2
HC general abbreviation for hydrocarbon
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
Term Description/Definition
HNO
3
H
2
S hydrogen sulfide
NO
2 nitrogen dioxide
NO
NO
X y nitrogen oxides, here defined as the sum of NO and NO
2 nitrogen oxides, often called odd nitrogen: the sum of NO compounds such as HNO
X
plus other
(definitions vary widely and may include nitrate (NO
3
),
PAN, N
2
3
O and other compounds as well)
NH
3
ammonia cm 3
O
2 molecular oxygen
O
3
ozone
SO
2 metric abbreviation for cubic centimeter (replaces the obsolete abbreviation
“cc”)
CPU
DAC
DAS
DCE
Central Processing Unit
Digital-to-Analog Converter
Data Acquisition System
Data Communication Equipment
DFU
DHCP
DIAG
DOM
Dry Filter Unit
Dynamic Host Configuration Protocol. A protocol used by LAN or Internet servers to automatically set up the interface protocols between themselves and any other addressable device connected to the network
Diagnostics , the diagnostic settings of the analyzer.
Disk On Module, a 44-pin IDE flash drive with up to 128MB storage capacity for instrument’s firmware, configuration settings and data
DOS
DRAM
DR-DOS
DTE
EEPROM
Disk Operating System
Dynamic Random Access Memory
Digital Research DOS
ESD
ETEST
Ethernet
FEP
Flash
FPI
Data Terminal Equipment
Electrically Erasable Programmable Read-Only Memory also referred to as a
FLASH chip or drive
Electro-Static Discharge
Electrical Test a standardized (IEEE 802.3) computer networking technology for local area networks (LANs), facilitating communication and sharing resources
Fluorinated Ethylene Propylene polymer, one of the polymers that Du Pont markets as Teflon ® non-volatile, solid-state memory
Fabry-Perot Interface : a special light filter typically made of a transparent plate with two reflecting surfaces or two parallel, highly reflective mirrors
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
IC
Term Description/Definition
GFC
I
2
C bus
Gas Filter Correlation analyzer components a clocked, bi-directional, serial bus for communication between individual
Integrated Circuit , a modern, semi-conductor circuit that can contain many basic components such as resistors, transistors, capacitors etc in a miniaturized package used in electronic assemblies
IP
IZS
Internet Protocol
Internal Zero Span
LAN
LCD
LED
LPM
MFC
PC/AT
PCB
PFA
PLC
PLD
PLL
PMT
P/N (or PN)
PSD
PTFE
PVC
Local Area Network
Liquid Crystal Display
Light Emitting Diode
Liters Per Minute
Mass Flow Controller
M/R
MOLAR MASS
Measure/Reference the mass, expressed in grams, of 1 mole of a specific substance. Conversely, one mole is the amount of the substance needed for the molar mass to be the same number in grams as the atomic mass of that substance.
NDIR
NIST-SRM
EXAMPLE: The atomic weight of Carbon is 12 therefore the molar mass of
Carbon is 12 grams. Conversely, one mole of carbon equals the amount of carbon atoms that weighs 12 grams.
Atomic weights can be found on any Periodic Table of Elements.
Non-Dispersive Infrared
National Institute of Standards and Technology - Standard Reference Material
PC Personal Computer
PCA Printed Circuit Assembly, the PCB with electronic components, ready to use
Personal Computer / Advanced Technology
Printed Circuit Board , the bare board without electronic component
Per-Fluoro-Alkoxy , an inert polymer; one of the polymers that Du Pont markets as Teflon ®
Programmable Logic Controller , a device that is used to control instruments based on a logic level signal coming from the analyzer
Programmable Logic Device
Phase Lock Loop
Photo Multiplier Tube , a vacuum tube of electrodes that multiply electrons collected and charged to create a detectable current signal
Part Number
Prevention of Significant Deterioration
Poly-Tetra-Fluoro-Ethylene , a very inert polymer material used to handle gases that may react on other surfaces; one of the polymers that Du Pont markets as
Teflon
®
Poly Vinyl Chloride , a polymer used for downstream tubing
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
SLPM
Term Description/Definition
Rdg Reading
RS-232 specification and standard describing a serial communication method between
DTE (Data Terminal Equipment) and DCE (Data Circuit-terminating Equipment) devices, using a maximum cable-length of 50 feet
RS-485
SAROAD specification and standard describing a binary serial communication method among multiple devices at a data rate faster than RS-232 with a much longer distance between the host and the furthest device
Storage and Retrieval of Aerometric Data
SLAMS
STP
TCP/IP
State and Local Air Monitoring Network Plan
Standard Liters Per Minute of a gas at standard temperature and pressure
Standard Temperature and Pressure
Transfer Control Protocol / Internet Protocol , the standard communications protocol for Ethernet devices
Thermal Electric Cooler TEC
TPC
USB
Temperature/Pressure Compensation
Universal Serial Bus : a standard connection method to establish communication between peripheral devices and a host controller, such as a mouse and/or touchscreen and a personal computer or laptop
Variables , the variable settings of the instrument VARS
V-F
Z/S
Voltage-to-Frequency
Zero / Span
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5. OPTIONAL HARDWARE AND SOFTWARE
This includes a brief description of the hardware and software options available for the Model GFC
7000TA Gas Filter Correlation Carbon Dioxide Analyzer. For assistance with ordering these options please contact the Sales department of Teledyne Analytical Instruments at:
TELEDYNE ELECTRONIC TECHNOLOGIES
Analytical Instruments
16830 Chestnut Street
City of Industry, CA 91748
Telephone: (626) 934-1500
Fax: (626) 961-2538
Web: www.teledyne-ai.com
5.1. Rack Mount Kits (Options 20A, 20B, 21 and 23)
OPTION NUMBER DESCRIPTION
20A
20B
21
Rack mount brackets with 26 in. chassis slides.
Rack mount brackets with 24 in. chassis slides.
Rack mount brackets only
23 Rack Mount for External Pump Pack (No Slides).
Each of these options permits the Analyzer to be mounted in a standard 19" x 30" RETMA rack.
5.2. Current Loop Analog Outputs (Option 41)
This option adds isolated, voltage-to-current conversion circuitry to the analyzer’s analog outputs. This option may be ordered separately for any of the analog outputs; it can be installed at the factory or added later. Call TAI sales for pricing and availability.
The current loop option can be configured for any output range between 0 and 20 mA. Figure 5-1 provides installation instructions and illustrates a sample combination of one current output and two voltage outputs configuration. Information on calibrating or adjusting these outputs can be found in
Section 6.13.4.4.
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
Figure 5-1: Current Loop Option Installed on the Motherboard
5.2.1. Converting Current Loop Analog Outputs to Standard Voltage
Outputs
NOTE
Servicing or handling of circuit components requires electrostatic discharge protection, i.e. ESD grounding straps, mats and containers. Failure to use ESD protection when working with electronic assemblies will void the instrument warranty.
See Section 12 for more information on preventing ESD damage.
To convert an output configured for current loop operation to the standard 0 to 5 VDC output operation:
1. Turn off power to the analyzer.
2. If a recording device was connected to the output being modified, disconnect it.
3. Remove the top cover
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
Remove the set screw located in the top, center of the rear panel
Remove the screws fastening the top cover to the unit (four per side).
Slide the cover back and lift straight up .
4. Disconnect the current loop option PCA from the appropriate connector on the motherboard (see
Figure 5-1).
5. Place a shunt between the leftmost two pins of the connector (see Figure 5-1).
6. Reattach the top case to the analyzer.
7. The analyzer is now ready to have a voltage-sensing, recording device attached to that output
5.3. Expendable Kits (Options 42C, 42D and 43)
OPTION NUMBER
OPT 42C
OPT 42D
OPT 43
DESCRIPTION
1 year’s supply of replacement of 47mm dia. particulate filters
1 full replacement’s volume of indicating soda-lime for the external CO
2
scrubber included with options 51 & 53 (approximate active lifetime: 1 year)
Options 42 C & 42D
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
5.4. Calibration Valves Options
There are four available options involving Zero/span valves. From an operational and software standpoint, all of the options are the same, only the source of the span and zero gases are different.
5.4.1. Ambient Zero/Pressurized Span Valve
This option requires that both zero air and span gas be supplied from external sources. It is specifically designed for applications where span gas will be supplied from a pressurized bottle of calibrated CO
2
gas.
A critical flow control orifice, internal to the instrument ensures that the proper flow rate is maintained. An internal vent line, isolated by a shutoff valve ensures that the gas pressure of the span gas is reduced to ambient atmospheric pressure. Normally zero air would be supplied from zero air modules such as a
Teledyne Instruments Model 701.
In order to ensure that span gas does not migrate backwards through the vent line and alter the concentration of the span gas, a gas line not less than 2 meters in length should be attached to the vent span outlet on the rear panel of the analyzer. To prevent the buildup of back pressure, this vent line should not be greater than 10 meters in length.
The following table describes the state of each valve during the analyzer’s various operational modes.
Table 5-1: Ambient Zero/Pressurized Span Valve Operating States
MODE VALVE
SAMPLE
(Normal State)
ZERO CAL
Sample/Cal
Zero/Span
Shutoff Valve
Sample/Cal
Zero/Span
Shutoff Valve
CONDITION
Open to SAMPLE inlet
Open to IZS inlet
Closed
Open to ZERO/SPAN valve
Open to IZS inlet
Closed
SPAN CAL
Sample/Cal
Zero/Span
Open to ZERO/SPAN valve
Open to SHUTOFF valve
Shutoff Valve Open to PRESSURE SPAN Inlet
The minimum span gas flow rate required for this option is 800 cm
3
/min.
The state of the zero/span valves can also be controlled:
Manually from the analyzer’s front panel by using the SIGNAL I/O controls located under the DIAG
Menu (Section 6.13.2),
By activating the instrument’s AutoCal feature (Section 7.6),
Remotely by using the external digital control inputs (Section 6.15.1.2 and Section 7.5.2), or;
Remotely through the RS-232/485 serial I/O ports (see Appendix A-6 for the appropriate commands).
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
Figure 5-2: Internal Pneumatic Flow – Ambient Zero/Pressurized Span Valves
5.4.2. Ambient Zero/Ambient Span Valve
This valve option is intended for applications where zero air is supplied by a zero air generator like a bottle of N
2
and span gas are being supplied by Gas Dilution Calibrator like the Teledyne Instruments
Model 700 or 702. Internal zero/span and sample/cal valves control the flow of gas through the instrument, but because the calibrator limits the flow of span gas no shutoff valve is required.
In order to ensure that span gas does not migrate backwards through the vent line and alter the concentration of the span gas, a gas line not less than 2 meters in length should be attached to the vent span outlet on the rear panel of the analyzer. To prevent the buildup of back pressure, this vent line should not be greater than 10 meters in length.
The following table describes the state of each valve during the analyzer’s various operational modes.
Table 5-2: Ambient Zero/Ambient Span Valve Operating States
Mode Valve
SAMPLE
(Normal State)
Sample/Cal
Zero/Span
ZERO CAL
SPAN CAL
Sample/Cal
Zero/Span
Sample/Cal
Zero/Span
Condition
Open to SAMPLE inlet
Open to IZS inlet
Open to ZERO/SPAN valve
Open to IZS inlet
Open to ZERO/SPAN valve
Open to PRESSURE SPAN inlet
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
The minimum span gas flow rate required for this option is 800 cm
3
/min.
The state of the zero/span valves can also be controlled:
Manually from the analyzer’s front panel by using the SIGNAL I/O controls located under the DIAG
Menu (Section 6.13.2),
By activating the instrument’s AutoCal feature (Section 7.6),
Remotely by using the external digital control inputs (Sections 6.15.1.2 and 7.5.2), or
Remotely through the RS-232/485 serial I/O ports (see Appendix A-6).
Figure 5-3: Internal Pneumatic Flow – Ambient Zero/Ambient Span
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FAQ
5.5. Communication Options
Model GFC7000TA Carbon Dioxide Analyzer
5.5.1. Communications Cables
Shielded, straight-through DB-9F to DB-25M cable, about 1.8 m long.
Used to interface with older computers or code activated switches with
DB-25 serial connectors.
5.5.2. RS-232 Multidrop (Option 62)
The multidrop option is used with any of the RS-232 serial ports to enable communications of up to eight analyzers with the host computer over a chain of RS-232 cables via the instruments COM1 port (labeled
RS232 . It is subject to the distance limitations of the RS 232 standard.
The option consists of a small printed circuit assembly, which is seated on the analyzer’s CPU card (see
Figure 5-4) and is connected to the RS-232 and COM2 DB9 connectors on the instrument’s back panel via a cable to the motherboard. One option 62 is required for each analyzer along with one 6’ straightthrough, DB9 male DB9 Female cable (P/N WR0000101).
For information on using and setting up this option (See Section 6.11.7)
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Figure 5-4: Multi-drop/LVDS PCA Seated on CPU
5.6. Oxygen Sensor (OPT 65)
5.6.1. Theory of Operation
5.6.1.1. Paramagnetic measurement of O
2
The oxygen sensor used in the GFC 7000TA analyzer utilizes the fact that oxygen is attracted into strong magnetic field; most other gases are not, to obtain fast, accurate oxygen measurements.
The sensor’s core is made up of two nitrogen filled glass spheres, which are mounted on a rotating suspension within a magnetic field (Figure 5-7). A mirror is mounted centrally on the suspension and light is shone onto the mirror that reflects the light onto a pair of photocells. The signal generated by the photocells is passed to a feedback loop, which outputs a current to a wire winding (in effect, a small DC electric motor) mounted on the suspended mirror.
Oxygen from the sample stream is attracted into the magnetic field displacing the nitrogen filled spheres and causing the suspended mirror to rotate. This changes the amount of light reflected onto the photocells and therefore the output levels of the photocells. The feedback loop increases the amount of current fed into the winding in order to move the mirror back into its original position. The more O loop.
2 present, the more the mirror moves and the more current is fed into the winding by the feedback control
A sensor measures the amount of current generated by the feedback control loop which is directly proportional to the concentration of oxygen within the sample gas mixture (see Figure 5-7).
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
Figure 5-5: Oxygen Sensor - Principle of Operation
5.6.1.2. Operation within the GFC 7000TA Analyzer
The oxygen sensor option is transparently integrated into the core analyzer operation. All functions can be viewed or accessed through the front panel, just like the functions for CO
2
O
2
concentration is displayed in the upper right-hand corner, alternating with CO concentration.
2
Test functions for O
2 other test functions.
slope and offset are viewable from the front panel along with the analyzer’s
O
2
sensor calibration is performed via the front panel CAL function and is performed in a nearly identical manner as the standard CO
2
calibration. See Section 3.3.1 for more details.
Stability of the O
2
sensor can be viewed via the front panel (see Section 3.3.2.1).
A signal representing the currently measured O
2
concentration is available.
The O
2
concentration range is 0-100% (user selectable) with 0.1% precision and accuracy and is available to be output via the instrument’s analog output channel A3 (See Section 6.13.4).
The temperature of the O
2
sensor is maintained at a constant 50° C by means of a PID loop and can be viewed on the front panel as test function O2 TEMP.
The O
2
sensor assembly itself does not have any serviceable parts and is enclosed in an insulated canister.
5.6.1.3. Pneumatic Operation of the O
2
Sensor
Pneumatically, the O
2
sensor is connected to the bypass manifold and draws a flow of about 120 cm³/min in addition to the normal sample flow rate and is separately controlled with its own critical flow orifice. Figure 5-8 shows the internal pneumatics of the GFC 7000TA with the O2 Sensor installed.
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
Figure 5-6: GFC 7000TA – Internal Pneumatics with O2 Sensor Option 65
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FAQ Model GFC7000TA Carbon Dioxide Analyzer
5.7. Special Features
5.7.1. Dilution Ratio Option
The Dilution Ration Option is a software option that is designed for applications where the Sample gas is diluted before being analyzed by the Model GFC 7000TA. Typically this occurs in Continuous Emission
Monitoring (CEM) applications where the quality of gas in a smoke stack is being tested and the sampling method used to remove the gas from the stack dilutes the gas.
Once the degree of dilution is known, this feature allows the user to add an appropriate scaling factor to the analyzer’s CO
2
concentration calculation so that the Measurement Range and concentration values displayed on the instrument’s Front Panel Display and reported via the Analog and Serial Outputs reflect the undiluted values.
Instructions for using the dilution ratio option can be found in Section 6.8.7.
5.7.2. Maintenance Mode Switch
TAI’s instruments can be equipped with a switch that places the instrument in maintenance mode. When present, the switch accessed by opening the hinged front panel and is located on the rearward facing side of the display/touchscreen driver PCA; on the left side; near the particulate filter.
When in maintenance mode the instrument ignores all commands received via the com ports that alter the operation state of the instrument. This includes all calibration commands, diagnostic menu commands and the reset instrument command. The instrument continues to measure concentration and send data when requested.
This option is of particular use for instruments connected to multidrop or Hessen protocol networks.
5.7.3. Second Language Switch
TAI’s instruments can be equipped with switch that activates an alternate set of display message in a language other than the instruments default language. When present, the switch accessed by opening the hinged front panel and is located on the rearward facing side of the display/touchscreen driver PCA; on the right side.
To activate this feature, the instrument must also have a specially programmed Disk on Chip containing the second language.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6. OPERATING INSTRUCTIONS
To assist in navigating the analyzer’s software, a series of menu trees can be found in Appendix A-1 of this manual.
NOTES
The flow charts appearing in this contain typical representations of the analyzer’s display during the various operations being described. These representations may differ slightly from the actual display of your instrument.
The ENTR button may disappear if you select a setting that is invalid or out of the allowable range for that parameter, such as trying to set the 24-hour clock to 25:00:00. Once you adjust the setting to an allowable value, the ENTR button will re-appear.
6.1. Overview of Operating modes
The GFC 7000TA software has a variety of operating modes. Most commonly, the analyzer will be operating in SAMPLE mode. In this mode, a continuous read-out of the CO
2
concentration is displayed on the front panel and output as an analog voltage from rear panel terminals, calibrations can be performed, and TEST functions and WARNING messages can be examined.
The second most important operating mode is SETUP mode. This mode is used for performing certain configuration operations, such as for the DAS system, the reporting ranges, or the serial (RS-232/RS-
485/Ethernet) communication channels. The SET UP mode is also used for performing various diagnostic tests during troubleshooting.
Figure 6-1: Front Panel Display
The Mode field of the front panel display indicates to the user which operating mode the unit is currently running.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Besides SAMPLE and SETUP, other modes the analyzer can be operated in are:
Table 6-1: Analyzer Operating modes
MODE MEANING
DIAG
M-P CAL
SAMPLE
SAMPLE A
SETUP
1
One of the analyzer’s diagnostic modes is being utilized (See Section 6.13).
This is the basic, multi-point calibration mode of the instrument and is activated by pressing the CAL key.
Sampling normally, flashing indicates adaptive filter is on.
Indicates that unit is in SAMPLE Mode and AUTOCAL feature is activated.
SETUP mode is being used to configure the analyzer (CO
2
sampling will continue during this process).
SPAN CAL A Unit is performing span cal procedure initiated automatically by the analyzer’s AUTOCAL feature.
SPAN CAL M
Unit is performing span cal procedure initiated manually by the user.
SPAN CAL R
ZERO CAL A
Unit is performing span cal procedure initiated remotely via the RS-232, RS-4485 or digital i/o control inputs.
Unit is performing zero cal procedure initiated automatically by the analyzer’s AUTOCAL feature.
ZERO CAL M
Unit is performing zero cal procedure initiated manually by the user.
ZERO CAL R Unit is performing zero cal procedure initiated remotely via the RS-232, RS-4485 or digital I/O control inputs.
1
The revision of the Teledyne Instruments software installed in this analyzer will be displayed following the word
SETUP . E.g. “SETUP G.4
”
Finally, the various CAL modes allow calibration of the analyzer. Because of its importance, this mode is described separately in Section 7.
6.2. Sample Mode
This is the analyzer’s standard operating mode. In this mode the instrument is analyzing the gas in the sample chamber, calculating CO
2
concentration and reporting this information to the user via the front panel display, the analog outputs and, if set up properly, the RS-232/485/Ethernet ports.
NOTE
A value of “XXXX” displayed in the CO2 Concentration field means that the M/R ratio is invalid because CO2 REF is either too high (> 4950 mVDC) or too low (<
1250 VDC).
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.2.1. Test Functions
Test functions are shown on the front panel display while the analyzer is in SAMPLE mode. They provide information about the present operating status of the instrument and can be used troubleshooting and can be recorded in one of the DAS channels (Section 6.7) for data analysis. To view, press the <TST TST> buttons.
Table 6-2: Test Functions Defined
MEANING
Range RANGE
RANGE1
RANGE2
1
1
PPB, PPM,
UGM, MGM
The full scale limit at which the reporting range of the analyzer is currently set. THIS IS NOT the Physical Range of the instrument.
See Section 6.8.1 for more information.
CO
CO
O
2
2
2
Range
Stability
Measure
Reference
Measurement /
Reference Ratio
Sample Pressure
Sample Flow
O2 RANGE
STABIL
MEAS
REF
MR Ratio
PRES
SAMPLE FL
%
PPB, PPM
UGM, MGM
MV
MV
-
In-Hg-A cc/min
The range setting for the O
2
Sensor
Standard deviation of CO
2
concentration readings. Data points are recorded every ten seconds using the last 25 data points.
The demodulated, peak IR detector output during the measure portion of the GFC Wheel cycle.
The demodulated, peak IR detector output during the reference portion of the GFC wheel cycle.
The result of CO2 MEAS divided by CO2 REF. This ratio is the primary value used to compute CO
2
concentration. The value displayed is not linearized.
The absolute pressure of the Sample gas as measured by a pressure sensor located inside the sample chamber.
Sample mass flow rate. This is computed from the differential between the pressures measured up-stream and down-stream of the sample critical flow orifice pressures.
Sample
Temperature
Bench
Temperature
Wheel
Temperature
SAMP TEMP
BENCH TEMP
WHEEL TEMP
C
C
C
The temperature of the gas inside the sample chamber.
Optical bench temperature.
Filter wheel temperature.
Box Temperature
O
2
Cell
Temperature
2
BOX TEMP
O2 CELL
TEMP
2
C
C
The temperature inside the analyzer chassis.
O
2
sensor cell temperature.
Photo-detector
Temp. Control
Voltage
Slope
PHT DRIVE mV
The drive voltage being supplied to the thermoelectric coolers of the
IR photo-detector by the sync/demod Board.
Offset
SLOPE
OFFSET
-
-
The sensitivity of the instrument as calculated during the last calibration activity. The SLOPE parameter is used to set the span calibration point of the analyzer.
The overall offset of the instrument as calculated during the last calibration activity. The OFFSET parameter is used to set the zero point of the analyzer response.
O2 Sensor Slope
2
O2 SLOPE
O2 Sensor Offset
2
O2 OFFSET
Test channel output signal
TEST
- O
- O mV, mA
2
2
slope, computed during zero/span calibration.
offset, computed during zero/span calibration.
Displays the signal level of the TEST analog output channel. Only appears when the TEST channel has been activated.
Current Time
TIME -
The current time. This is used to create a time stamp on DAS readings, and by the AUTOCAL feature to trigger calibration events.
1
Only appears when the instrument’s reporting range mode is set for DUAL or AUTO
2 Only appears when the optional O
2
sensor is installed.
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Operating Instructions
To view the TEST Functions press:
Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE
RANGE = 500.000 PPM
CO2 = XXX.X
< TST TST >
CAL SETUP
Toggle <TST TST> buttons
1
2
to scroll through list of
Only appears instrument is set for DUAL or AUTO reporting range modes.
Only appears if O
2
Sensor
Option is installed.
RANGE
RANGE1
1
RANGE2
1
O
2
RANGE
STABIL
MEAS
REF
MR RATIO
PRES
SAMP FL
SAMP TEMP
BENCH TEMP
WHEEL TEMP
BOX TEMP
PHT DRIVE
SLOPE
OFFSET
TEST
TIME
Refer to
Table 6-2 for definitions of these test functions.
Figure 6-2: Viewing TEST Functions
NOTE
A value of “XXXX” displayed for any of the TEST functions indicates an out-ofrange reading or the analyzer’s inability to calculate it.
All pressure measurements are represented in terms of absolute pressure.
Absolute, atmospheric pressure is 29.92 in-Hg-A at sea level. It decreases about 1 in-Hg per 300 m gain in altitude. A variety of factors such as air conditioning and passing storms can cause changes in the absolute atmospheric pressure.
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6.2.2. Warning Messages
The most common instrument failures will be reported as a warning on the analyzer’s front panel and through the COM ports. Section 11.1.1 explains how to use these messages to troubleshoot problems.
Section 3.2.3 shows how to view and clear warning messages.
Table 6-3 lists all warning messages for the current version of software.
Table 6-3: List of Warning Messages
MESSAGE MEANING
ANALOG CAL WARNING The instrument’s A/D circuitry or one of its analog outputs is not calibrated.
BENCH TEMP WARNING The Temperature of the optical bench is outside the specified limits.
BOX TEMP WARNING Remote span calibration failed while the dynamic span feature was set to turned on
CANNOT DYN SPAN Remote zero calibration failed while the dynamic zero feature was set to turned on
CANNOT DYN ZERO
CONFIG INITIALIZED
Configuration was reset to factory defaults or was erased.
CONC ALRM1 WARNING Concentration alarm 1 is enabled and the measured CO
2
level is ≥ the set point.
CONC ALRM2 WARNING Concentration alarm 2 is enabled and the measured CO
2
level is ≥ the set point.
Configuration storage was reset to factory configuration or erased.
DATA INITIALIZED
REAR BOARD NOT DET
DAS data storage was erased.
O2 CELL TEMP WARN O
2
sensor cell temperature outside of warning limits.
PHOTO TEMP WARNING The temperature of the IR photometer is outside the specified limits.
The CPU is unable to communicate with the motherboard.
RELAY BOARD WARN The firmware is unable to communicate with the relay board.
SAMPLE FLOW WARN The flow rate of the sample gas is outside the specified limits.
SAMPLE PRESS WARN Sample gas pressure outside of operational parameters.
The temperature of the sample gas is outside the specified limits. SAMPLE TEMP WARN
SOURCE WARNING The IR source may be faulty.
The computer was rebooted. SYSTEM RESET
WHEEL TEMP WARNING The Gas Filter Correlation wheel temperature is outside the specified limits.
Teledyne Analytical Instruments 67
Operating Instructions
To view and clear warning messages:
TEST deactivates warning messages
Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE SYSTEM RESET CO2 = 0.00
TEST CAL MSG CLR SETUP
SAMPLE RANGE=500.000 PPM CO2 = 0.00
< TST TST > CAL MSG CLR SETUP
MSG displays warning messages.
NOTE:
If the warning message persists after several attempts to clear it, the message may indicate a real problem and not an artifact of the warm-up period
SAMPLE
TEST CAL
SYSTEM RESET
MSG
CO2 = 0.00
CLR SETUP
Press CLR to clear the current message.
If more than one warning is active, the next message will take its place
Once the last warning has been cleared, the analyzer returns to
SAMPLE mode
Figure 6-3: Viewing and Clearing GFC 7000TA WARNING Messages
6.3. Calibration Mode
Pressing the CAL key switches the GFC 7000TA into multi-point calibration mode. In this mode, the user can calibrate the instrument or check the instruments calibration with the use of calibrated zero or span gases.
If the instrument includes either the zero/span valve option or IZS option, the display will also include
CALZ and CALS keys. Pressing either of these keys also puts the instrument into multipoint calibration mode.
The key is used to initiate a calibration of the zero point.
The key is used to calibrate the span point of the analyzer. It is recommended that this span calibration is performed at 90% of full scale of the analyzer’s currently selected reporting range.
Because of their critical importance and complexity, calibration operations are described in detail in
Section 7 of this manual. For more information concerning the zero/span, zero/span and IZS valve options, See Section 5.4.
Teledyne Analytical Instruments 68
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.4. SETUP MODE
The SETUP mode contains a variety of choices that are used to configure the analyzer’s hardware and software features, perform diagnostic procedures, gather information on the instruments performance and configure or access data from the internal data acquisition system (DAS). For a visual representation of the software menu trees, refer to Appendix A. The areas access under the Setup mode are:
MODE OR
FEATURE
Analyzer
Configuration
Table 6-4: Primary Setup Mode Features and Functions
TOUCHSCREEN
BUTTON
External Communication
Channel Configuration
System Status Variables
System Diagnostic Features
CO
2
Concentration Alarms
CFG
DESCRIPTION
Lists key hardware and software configuration information
Auto Cal Feature
ACAL
Used to set up and operate the AutoCal feature.
Only appears if the analyzer has one of the internal valve options installed
Used to set up the DAS system and view recorded data
Internal Data
Acquisition (DAS)
Analog Output
Reporting Range
Configuration
Calibration
Password Security
Internal Clock
Configuration
Advanced SETUP
Features
DAS
RNGE
PASS
CLK
MORE
Used to configure the output signals generated by the instruments Analog outputs.
Turns the calibration password feature ON/OFF
Used to Set or adjust the instrument’s internal clock
This button accesses the instruments secondary setup menu
Table 6-5: Secondary Setup Mode Features and Functions
MODE OR FEATURE
TOUCHSCREEN
BUTTON
DESCRIPTION
COMM
VARS
DIAG
ALRM
Used to set up and operate the analyzer’s various external I/O channels including RS-232; RS-485, modem communication and/or Ethernet access.
Used to view various variables related to the instruments current operational status
Used to access a variety of functions that are used to configure, test or diagnose problems with a variety of the analyzer’s basic systems
Used to activate the analyzer’s two gas concentration status alarms and set the alarm limits
MANUAL
SECTION
6.5
7.6
6.7
6.8
6.9
6.10
See
Table 6-5
MANUAL
SECTION
6.11 &
6.15
6.12
6.13
6.14
NOTE
Any changes made to a variable during one of the following procedures is not acknowledged by the instrument until the ENTR button is pressed
If EXIT is pressed before the ENTR button, the analyzer will beep alerting the user that the newly entered value has been lost.
Teledyne Analytical Instruments 69
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.5. SETUP CFG: Viewing the Analyzer’s Configuration
Information
Pressing the CFG button displays the instrument configuration information. This display lists the analyzer model, serial number, firmware revision, software library revision, CPU type and other information. Use this information to identify the software and hardware when contacting customer service. Special instrument or software features or installed options may also be listed here.
SAMPLE* RANGE = 500.000 PPB CO2 =X.XXX
< TST TST > CAL SETUP
Press NEXT and PREV to scroll through the following list of Configuration information:
MODEL NAME
PART NUMBER
SERIAL NUMBER
SOFTWARE REVISION
SAMPLE
PRIMARY SETUP MENU
CFG
DAS RNGE PASS CLK MORE EXIT
Press EXIT at any time to return to the
SAMPLE display
LIBRARY REVISION
iCHIP SOFTWARE REVISION 1
HESSEN PROTOCOL REVISION 1
ACTIVE SPECIAL SOFTWARE
OPTIONS
1
CPU TYPE
DATE FACTORY CONFIGURATION
SAVED
SAMPLE
T360 CO2 ANALYZER
NEXT PREV
EXIT
Press EXIT at any time to return to SETUP menu
1 Only appears if relevant option of Feature is active.
6.6. SETUP ACAL: Automatic Calibration
Instruments with one of the internal valve options installed can be set to automatically run calibration procedures and calibration checks. These automatic procedures are programmed using the submenus and functions found under the ACAL menu.
A menu tree showing the ACAL menu’s entire structure can be found in Appendix A-1 of this manual.
Instructions for using the ACAL feature are located in the Section 7.6 of this manual along with all other information related to calibrating the analyzer.
Teledyne Analytical Instruments 70
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7. SETUP DAS: Using the Data Acquisition System (DAS)
The GFC 7000TA analyzer contains a flexible and powerful, internal data acquisition system (DAS) that enables the analyzer to store concentration and calibration data as well as a host of diagnostic parameters. The DAS of the GFC 7000TA can store up to about one million data points, which can, depending on individual configurations, cover days, weeks or months of valuable measurements. The data are stored in non-volatile memory and are retained even when the instrument is powered off. Data are stored in plain text format for easy retrieval and use in common data analysis programs (such as spreadsheet-type programs).
The DAS is designed to be flexible, users have full control over the type, length and reporting time of the data. The DAS permits users to access stored data through the instrument’s front panel or its communication ports. Using APICOM, data can even be retrieved automatically to a remote computer for further processing.
The principal use of the DAS is logging data for trend analysis and predictive diagnostics, which can assist in identifying possible problems before they affect the functionality of the analyzer. The secondary use is for data analysis, documentation and archival in electronic format.
To support the DAS functionality, Teledyne Instruments offers APICOM, a program that provides a visual interface for remote or local setup, configuration and data retrieval of the DAS (Section 6.7). The
APICOM manual, which is included with the program, contains a more detailed description of the DAS structure and configuration.
The GFC 7000TA is configured with a basic DAS configuration, which is enabled by default. New data channels are also enabled by default but each channel may be turned off for later or occasional use.
Note that DAS operation is suspended while its configuration is edited through the front panel. To prevent such data loss, it is recommended to use the APICOM graphical user interface for DAS changes.
The green SAMPLE LED on the instrument front panel, which indicates the analyzer status, also indicates certain aspects of the DAS status:
Table 6-6: Front Panel Sample LED Status Indicators for DAS
LED STATE
OFF
BLINKING
ON
DAS Status
System is in calibration mode. Data logging can be enabled or disabled for this mode.
Calibration data are typically stored at the end of calibration periods, concentration data are typically not sampled, diagnostic data should be collected.
Instrument is in hold-off mode, a short period after the system exits calibrations. IDAS channels can be enabled or disabled for this period. Concentration data are typically disabled whereas diagnostic should be collected.
Sampling normally.
The DAS can be disabled only by disabling or deleting its individual data channels.
Teledyne Analytical Instruments 71
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.1. DAS Structure
The DAS is designed around the feature of a “record”. A record is a single data point of one parameter, stored in one (or more) data channels and generated by one of several triggering event. The entire DAS configuration is stored in a script, which can be edited from the front panel or downloaded, edited and uploaded to the instrument in form of a string of plain-text lines through the communication ports.
DAS data are defined by the PARAMETER type and are stored through different triggering EVENTS in data CHANNELS, which relate triggering events to data parameters and define certain operational functions related to the recording and reporting of the data.
6.7.1.1. DAS Channels
The key to the flexibility of the DAS is its ability to store a large number of combinations of triggering events and data parameters in the form of data channels. Users may create up to 20 data channels and each channel can contain one or more parameters. For each channel one triggering event is selected and up to 50 data parameters, which can be the same or different between channels. Each data channel has several properties that define the structure of the channel and allow the user to make operational decisions regarding the channel (Table 6-7).
Table 6-7: DAS Data Channel Properties
NAME The name of the data channel. “NONE” Up to 6 letters and digits
(more with APICOM, but only the first six are displayed on the front panel).
See Appendix A-5 For a complete list.
TRIGGERING
EVENT
NUMBER &
PARAMETER
LIST
STARTING
DATE
SAMPLE
PERIOD
REPORT
PERIOD
The event that triggers the data channel to measure and store its data parameters. See APPENDIX A-5 for a list of available triggering events.
A user-configurable list of data types to be recorded in any given channel. See APPENDIX A-5 for a list of available parameters
The starting date when a channel starts collecting data
The amount of time between each data point that is averaged into one mean reported every REPORT
PERIOD.
The amount of time between each channel data point.
NUMBER OF
RECORDS
RS-232
REPORT
CHANNEL
ENABLED
The number of reports that will be stored in the data file. Once the specified limit has been exceeded, the oldest data are over-written to make space for new data.
Enables the analyzer to automatically report channel values to the RS-232 ports.
Enables or disables the channel. Provides a convenient means to temporarily disable a data channel.
CAL HOLD OFF Disables sampling of data parameters while instrument is in calibration mode.
When enabled here – there is also a length of the
DAS HOLD OFF after calibration mode, which is set in the VARS menu.
ATIMER
1 – DETMES
01-JAN-03
000:01:00
000:01:00
100
OFF
ON
OFF
See Appendix A-5 For a complete list.
Any actual date in the past or future.
000:00:01 to 366:23:59
(Days:Hours:Minutes)
000:00:01 to
366:23:59
(Days:Hours:Minutes)
1 to 1 million, limited by available storage space.
OFF or ON
OFF or ON
OFF or ON
(Section 6.7.2.11.)
Teledyne Analytical Instruments 72
Operating Instructions
6.7.1.2. DAS Parameters
Model GFC7000TA Carbon Dioxide Analyzer
Data parameters are types of data that may be measured and stored by the DAS. For each Teledyne
Instruments analyzer model, the list of available data parameters is different, fully defined and not customizable. Appendix A-5 lists firmware specific data parameters for the analyzer. DAS parameters include things like CO
2
concentration measurements, temperatures of the various heaters placed around the analyzer, pressures and flows of the pneumatic subsystem and other diagnostic measurements as well as calibration data such as slope and offset.
Most data parameters have associated measurement units, such as mV, ppb, cm³/min, etc., although some parameters have no units. With the exception of concentration readings, none of these units of measure can be changed. To change the units of measure for concentration readings See Section 6.8.6.
Note
DAS does not keep track of the unit of each concentration value and DAS data files may contain concentrations in multiple units if the unit was changed during data acquisition.
Each data parameter has user-configurable functions that define how the data are recorded:
Table 6-8: DAS Data Parameter Functions
FUNCTION EFFECT
PARAMETER Instrument-specific parameter name.
SAMPLE MODE INST: Records instantaneous reading.
AVG: Records average reading during reporting interval.
MIN: Records minimum (instantaneous) reading during reporting interval.
MAX: Records maximum (instantaneous) reading during reporting interval.
PRECISION
SDEV: Records the standard deviation of the data points recorded during the reporting interval.
Decimal precision of parameter value (0-4).
STORE NUM.
SAMPLES
OFF: stores only the average (default).
ON: stores the average and the number of samples in each average for a parameter. This property is only useful when the AVG sample mode is used. Note that the number of samples is the same for all parameters in one channel and needs to be specified only for one of the parameters in that channel.
Users can specify up to 50 parameters per data channel (the GFC 7000TA provides about 30 parameters). However, the number of parameters and channels is ultimately limited by available memory.
Teledyne Analytical Instruments 73
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.1.3. DAS Triggering Events
Triggering events define when and how the DAS records a measurement of any given data channel.
Triggering events are firmware-specific and a complete list of Triggers for this model analyzer can be found in Appendix A-5. The most commonly used triggering events are:
ATIMER: Sampling at regular intervals specified by an automatic timer. Most trending information is usually stored at such regular intervals, which can be instantaneous or averaged.
EXITZR, EXITSP, SLPCHG (exit zero, exit span, slope change): Sampling at the end of
(irregularly occurring) calibrations or when the response slope changes. These triggering events create instantaneous data points, e.g., for the new slope and offset (concentration response) values at the end of a calibration. Zero and slope values are valuable to monitor response drift and to document when the instrument was calibrated.
WARNINGS: Some data may be useful when stored if one of several warning messages appears such as WTEMPW (GFC wheel temperature warning) or PPRESW (purge pressure warning). This is helpful for trouble-shooting by monitoring when a particular warning occurred.
6.7.2. Default DAS Channels
A set of default Data Channels has been included in the analyzer’s software for logging CO to:
2 concentration and certain predictive diagnostic data. These default channels include but are not limited
CONC: Samples CO
2
concentration at one minute intervals and stores an average every hour with a time and date stamp. Readings during calibration and calibration hold off are not included in the data. By default, the last 800 hourly averages are stored.
PNUMTC: Collects sample flow and sample pressure data at five minute intervals and stores an average once a day with a time and date stamp. This data is useful for monitoring the condition of the pump and critical flow orifice (sample flow) and the sample filter (clogging indicated by a drop in sample pressure) over time to predict when maintenance will be required. The last 360 daily averages (about 1 year) are stored.
CALDAT: Logs new slope and offset every time a zero or span calibration is performed. This Data
Channel also records the instrument readings just prior to performing a calibration. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See Section 9.1).
STBZRO: Logs the concentration stability, the electronic output of the IR detector of the most recent measure phase and the measure/reference ratio every time the instrument exits the zero calibration mode. Data from the last 200 zero calibrations is stored. A time and date stamp is recorded for every data point logged. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See Section 9.1).
STBSPN: Logs the electronic output of the IR detector of the most recent measure phase and the measure/reference ratio every time the instrument exits span calibration mode. Data from the last 200 zero calibrations is stored. A time and date stamp is recorded for every data point logged. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See
Section 9.1).
Teledyne Analytical Instruments 74
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
TEMP: Samples the analyzer’s bench temperature, box temperature and PHT cooler drive voltage every five minutes and records an average once every six hours. Data from the last 400 averaging periods is recorded. A time and date stamp is recorded for every data point logged. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See Section 9.1).
Note
The CALDAT, STBZRO and STBSPN channels collect data based on events (e.g. a calibration operation) rather than a timed interval. This does not represent any specific length of time since it is dependent on how often calibrations are performed.
Triggering Events and Data Parameters/Functions for these default channels are:
LIST OF CHANNELS
LIST OF PARAMETERS LIST OF PARAMETERS
NAME: CONC
EVENT: ATIMER
REPORT PERIOD: 000:01:00
NO. OF RECORDS: 800
RS-232 REPORT: OFF
CHANNEL ENABLED: ON
CAL HOLD OFF: ON
PARAMETER: CONC1
MODE: AVG
PRECISION: 1
STORE NUM SAMPLES OFF PARAMETER: SMPLFLW
MODE: AVG
PRECISION: 1
STORE NUM SAMPLES OFF
PARAMETER: SMPLPRS
MODE: AVG
PRECISION: 1
STORE NUM SAMPLES OFF
NAME: PNUMTC
EVENT: ATIMER
REPORT PERIOD: 001:00:00
NO. OF RECORDS: 360
RS-232 REPORT: OFF
CHANNEL ENABLED: ON
CAL HOLD OFF: OFF
PARAMETER: STABIL
MODE: INST
PRECISION:2
STORE NUM SAMPLES OFF
PARAMETER: DETMES
MODE: INST
PRECISION: 1
STORE NUM SAMPLES OFF
PARAMETER: RATIO
MODE: INST
PRECISION: 3
STORE NUM SAMPLES OFF
NAME: STBZRO
EVENT: EXITZR
REPORT PERIOD: N/A
NO. OF RECORDS:200
RS-232 REPORT: OFF
CHANNEL ENABLED: ON
CAL HOLD OFF: OFF
NAME: CALDAT
EVENT: SLPCHG
REPORT PERIOD: N/A
NO. OF RECORDS:200
RS-232 REPORT: OFF
CHANNEL ENABLED: ON
CAL HOLD OFF: OFF
NAME: STBSPN
EVENT: EXITSP
REPORT PERIOD: N/A
NO. OF RECORDS:200
RS-232 REPORT: OFF
CHANNEL ENABLED: ON
CAL HOLD OFF: OFF
PARAMETER: SLOPE1
MODE: INST
PRECISION:3
STORE NUM SAMPLES OFF
PARAMETER: OFSET1
MODE: INST
PRECISION: 1
STORE NUM SAMPLES OFF
PARAMETER: ZSCNC1
MODE: INST
PRECISION: 1
STORE NUM SAMPLES OFF
PARAMETER: DETMES
MODE: INST
PRECISION: 1
STORE NUM SAMPLES OFF
PARAMETER: RATIO
MODE: INST
PRECISION: 3
STORE NUM SAMPLES OFF
PARAMETER: BNTEMP
MODE: AVG
PRECISION:1
STORE NUM SAMPLES OFF
PARAMETER: BOXTMP
MODE: AVG
PRECISION: 1
STORE NUM SAMPLES OFF
PARAMETER: PHTDRV
MODE: AVG
PRECISION: 1
STORE NUM SAMPLES OFF
NAME: TEMP
EVENT: ATIMER
REPORT PERIOD: 000:06:00
NO. OF RECORDS:400
RS-232 REPORT: OFF
CHANNEL ENABLED: ON
CAL HOLD OFF: OFF
Figure 6-4: Default DAS Channels Setup
Teledyne Analytical Instruments 75
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
These default Data Channels can be used as they are, or they can be customized from the front panel to fit a specific application. They can also be deleted to make room for custom user-programmed Data
Channels.
Appendix A-5 lists the firmware-specific DAS configuration in plain-text format. This text file can either be loaded into APICOM and then modified and uploaded to the instrument or can be copied and pasted into a terminal program to be sent to the analyzer.
NOTE
Sending an DAS configuration to the analyzer through its COM ports will replace the existing configuration and will delete all stored data. Back up any existing data and the DAS configuration before uploading new settings.
These default Data Channels can be used as they are, or they can be customized from the front panel to fit a specific application. They can also be deleted to make room for custom user-programmed Data
Channels.
Appendix A-5 lists the firmware-specific DAS configuration in plain-text format. This text file can either be loaded into APICOM and then modified and uploaded to the instrument or can be copied and pasted into a terminal program to be sent to the analyzer.
NOTE
Sending an DAS configuration to the analyzer through its COM ports will replace the existing configuration and will delete all stored data. Back up any existing data and the DAS configuration before uploading new settings.
6.7.2.1. DAS Configuration Limits
The number of DAS objects are limited by the instrument’s finite storage capacity. For information regarding the maximum number of channels, parameters, and records and how to calculate the file size for each data channel, refer to the DAS manual downloadable from the TAI website at http://www.teledyne-api.com/manuals/.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.2.2. Viewing DAS Data and Settings
DAS data and settings can be viewed on the front panel through the following touchscreen buttons sequence.
TOUCHSCREEN BUTTON FUNCTIONS
BUTTON FUNCTION
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X
CFG
SETUP X.X
VIEW
DAS
EDIT
PRIMARY SETUP MENU
RNGE PASS CLK MORE
DATA ACQUISITION
EXIT
EXIT
<PRM
PRM>
Moves to the next Parameter
Moves to the previous
Parameter
NX10
NEXT
Moves the view forward 10 data points/channels
Moves to the next data point/channel
PREV
PV10
Moves to the previous data point/channel
Moves the view back 10 data points/channels
Buttons only appear when applicable.
SETUP X.X CONC
NEXT VIEW
: DATA AVAILABLE
EXIT
SETUP X.X
00:00:00 NXCNC1=0.0 PPM
PV10 PREV NEXT NX10 <PRM PRM> EXIT
SETUP X.X PNUMTC
PREV NEXT VIEW
: DATA AVAILABLE
EXIT
SETUP X.X
CALDAT : DATA AVAILABLE SETUP X.X
PREV NEXT VIEW EXIT
SETUP X.X
PV10 PREV
00:00:00 SMPFLW=000.0 cc / m
<PRM PRM> EXIT
00:00:00 NXSLP1=0.000
<PRM EXIT
SETUP X.X STBZRO : DATA AVAILABLE
PREV NEXT VIEW EXIT
SETUP X.X
PV10 PREV
STBSPN : DATA AVAILABLE SETUP X.X
PREV NEXT VIEW EXIT
SETUP X.X
PV10 PREV
SETUP X.X TEMP : DATA AVAILABLE
PREV NEXT VIEW EXIT
SETUP X.X
PV10 PREV
00:00:00 STABIL=0.000
<PRM EXIT
00:00:00 DETMES=0.000
<PRM EXIT
00:00:00 BOXTMP=0.000
<PRM EXIT
Teledyne Analytical Instruments 77
Operating Instructions
6.7.2.3. Editing DAS Data Channels
Model GFC7000TA Carbon Dioxide Analyzer
DAS configuration is most conveniently done through the APICOM remote control program. The following list of key strokes shows how to edit using the front panel.
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
EXIT will return to the previous SAMPLE display.
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
Main Data Acquisition Menu
SETUP X.X DATA ACQUISITION
VIEW EDIT EXIT
SAMPLE ENTER SETUP PASS : 818
8 1 8 ENTR EXIT
Moves the display up & down the list of
Data Channels
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL EDIT PRNT EXIT
Exits to the Main
Data Acquisition
Menu
Inserts a new Data
Channel into the list
BEFORE the Channel currently being displayed
Moves the display between the
PROPERTIES for this data channel.
Deletes The Data
Channel currently being displayed
SETUP X.X NAME:CONC
<SET SET> EDIT PRNT EXIT
Exports the configuration of all data channels to
RS-232 interface.
Exits returns to the previous Menu
Reports the configuration of current data channels to the RS-232 ports.
Allows to edit the channel name, see next key sequence.
When editing the data channels, the top line of the display indicates some of the configuration parameters. For example, the display line:
0) CONC: ATIMER, 4, 800 translates to the following configuration:
Channel No.: 0
NAME: CONC
TRIGGER EVENT: ATIMER
PARAMETERS: Four parameters are included in this channel
EVENT: This channel is set up to record 800 data points.
Teledyne Analytical Instruments 78
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To edit the name of a data channel, follow the above touchscreen button sequence and then press:
From the end of the previous button sequence …
SETUP X.X NAME:CONC
<SET SET> EDIT PRINT EXIT
SETUP X.X NAME:CONC
C O N C - - ENTR EXIT
ENTR accepts the new string and returns to the previous menu.
EXIT ignores the new string and returns to the previous menu.
Press each button repeatedly to cycle through the available character set:
0-9, A-Z, space ’ ~ !
# $ % ^ & * ( ) - _ = +[ ]
{ } < >\ | ; : , . / ?
6.7.2.4. Trigger Events
To edit the list of data parameters associated with a specific data channel, press:
From the DATA ACQUISITION menu
(see Section 6.7.2.2)
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL
EDIT
PRNT EXIT
Exits to the Main
Data Acquisition menu
SETUP X.X NAME:CONC
<SET SET> EDIT PRINT EXIT
SETUP X.X EVENT:ATIMER
<SET SET> EDIT PRINT EXIT
SETUP X.X
EVENT:ATIMER
<PREV NEXT> ENTR EXIT
Press each button repeatedly to cycle through the list of available trigger events.
ENTR accepts the new string and returns to the previous menu.
EXIT ignores the new string and returns to the previous menu.
Teledyne Analytical Instruments 79
Operating Instructions
6.7.2.5. Editing DAS Parameters
Model GFC7000TA Carbon Dioxide Analyzer
Data channels can be edited individually from the front panel without affecting other data channels.
However, when editing a data channel, such as during adding, deleting or editing parameters, all data for that particular channel will be lost, because the DAS can store only data of one format (number of parameter columns etc.) for any given channel. In addition, an DAS configuration can only be uploaded remotely as an entire set of channels. Hence, remote update of the DAS will always delete all current channels and stored data.
To modify, add or delete a parameter, follow the instruction shown in Section 6.7.2.2 then press:
From the DATA ACQUISITION menu
(see Section 6.7.2.2)
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL EDIT PRNT EXIT
Exits to the main
Data Acquisition menu
SETUP X.X NAME:CONC
<SET
SET>
EDIT PRINT EXIT
Press SET> button until…
YES will delete all data in that entire channel.
Moves the display between existing
Parameters
Inserts a new Parameter before the currently displayed Parameter
SETUP X.X PARAMETERS:1
<SET SET> EDIT PRINT EXIT
SETUP X.X EDIT PARAMS (DELETE DATA)
YES NO
Edit Data Parameter Menu
SETUP X.X 0) PARAM=CONC1, MODE=AVG
PREV NEXT INS DEL EDIT EXIT
Deletes the Parameter currently displayed.
NO returns to the previous menu and retains all data.
Exits to the main
Data Acquisition
Use to configure the functions for this Parameter. menu
Teledyne Analytical Instruments 80
Operating Instructions
To configure a specific data parameter, press:
Model GFC7000TA Carbon Dioxide Analyzer
FROM THE EDIT DATA PARAMETER MENU
(see previous section)
SETUP X.X
0) PARAM=CONC1, MODE=AVG
PREV NEXT INS DEL
EDIT
EXIT
SETUP X.X
PARAMETERS:CONC1
SET> EDIT EXIT
SETUP X.X
PARAMETERS: 1
PREV NEXT
EXIT
If more than on parameter is active for this channel, these cycle through list of existing Parameters.
SETUP X.X SAMPLE MODE:AVG
<SET SET> EDIT
EXIT
SETUP X.X SAMPLE MODE: INST
INST AVG MIN MAX
EXIT
Press the button for the desired mode
SETUP X.X PRECISION: 1
<SET SET> EDIT
EXIT
SETUP X.X PRECISION: 1
1
Set for 0-4
EXIT
ENTR
accepts the new setting and returns to the previous menu.
EXIT ignores the new setting and returns to the previous
<SET Returns to previous
Functions
SETUP X.X
STORE NUM. SAMPLES: OFF
<SET EDIT EXIT
SETUP X.X
STORE NUM. SAMPLES: OFF
ENTR EXIT OFF
Turn ON or OFF
Teledyne Analytical Instruments 81
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.2.6. Sample Period and Report Period
The DAS defines two principal time periods by which sample readings are taken and permanently recorded:
SAMPLE PERIOD: Determines how often DAS temporarily records a sample reading of the parameter in volatile memory. The SAMPLE PERIOD is set to one minute by default and generally cannot be accessed from the standard DAS front panel menu, but is available via the instruments communication ports by using APICOM or the analyzer’s standard serial data protocol.
SAMPLE PERIOD is only used when the DAS parameter’s sample mode is set for AVG, MIN or
MAX .
REPORT PERIOD: Sets how often the sample readings stored in volatile memory are processed,
(e.g. average, minimum or maximum are calculated) and the results stored permanently in the instruments Disk-on-Chip as well as transmitted via the analyzer’s communication ports. The
REPORT PERIOD may be set from the front panel.
If the INST sample mode is selected the instrument stores and reports an instantaneous reading of the selected parameter at the end of the chosen REPORT PERIOD
In AVG, MIN or MAX sample modes, the settings for the SAMPLE PERIOD and the REPORT PERIOD determine the number of data points used each time the average, minimum or maximum is calculated, stored and reported to the com ports. The actual sample readings are not stored past the end of the of the chosen REPORT PERIOD.
Also, the SAMPLE PERIOD and REPORT PERIOD intervals are synchronized to the beginning and end of the appropriate interval of the instruments internal clock.
If were set for one minute the first reading would occur at the beginning of the next full minute according to the instrument’s internal clock. the were set for of one hour the first report activity would occur at the beginning of the next full hour according to the instrument’s internal clock.
EXAMPLE: Given the above settings, if DAS were activated at 7:57:35 the first sample would occur at 7:58 and the first report would be calculated at 8:00 consisting of data points for 7:58.
7:59 and 8:00.
During the next hour (from 8:01 to 9:00) the instrument will take a sample reading every minute and include 60 sample readings.
When the STORE NUM. SAMPLES feature is turned on the instrument will also store how many sample readings were used for the AVG, MIN or MAX calculation but not the readings themselves.
REPORT PERIODS IN PROGRESS WHEN INSTRUMENT IS POWERED OFF
If the instrument is powered off in the middle of a REPORT PERIOD, the samples accumulated so far during that period are lost. Once the instrument is turned back on, the DAS restarts taking samples and temporarily them in volatile memory as part of the REPORT PERIOD currently active at the time of restart. At the end of this REPORT PERIOD only the sample readings taken since the instrument was turned back on will be included in any AVG, MIN or MAX calculation. Also, the STORE NUM. SAMPLES feature will report the number of sample readings taken since the instrument was restarted.
Teledyne Analytical Instruments 82
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To define the REPORT PERIOD, follow the instruction shown in Section 6.7.2.2 then press:
From the DATA ACQUISITION menu
(see Section 6.7.2.2)
Use the PREV and NEXT buttons to scroll to the data channel to be edited.
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL EDIT PRNT EXIT
Exits to the main
Data Acquisition menu.
SETUP X.X NAME:CONC
<SET SET> EDIT PRINT EXIT
Press SET> key until you reach REPORT PERIOD …
SETUP X.X REPORT PERIOD:000:01:00
<SET SET> EDIT PRINT EXIT
Set the number of days between reports (0-366).
Press buttons to set hours between reports in the format :
HH:MM (max: 23:59). This is a
24 hour clock . PM hours are 13 thru 23, midnight is 00:00.
Example 2:15 PM = 14:15
SETUP X.X REPORT PERIODD:DAYS:0
0 0 0 ENTR EXIT
SETUP X.X REPORT PERIODD:TIME:01:01
0 1 0 0 ENTR EXIT
IIf at any time an illegal entry is selected (e.g., days > 366) the ENTR button will disappear from the display.
ENTR accepts the new string and returns to the previous menu.
EXIT ignores the new string and returns to the previous menu.
Teledyne Analytical Instruments 83
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.2.7. Number of Records
The number of data records in the GFC 7000TA is limited to about a cumulative one million data points in all channels (one megabyte of space on the disk-on-chip). However, the actual number of records is also limited by the total number of parameters and channels and other settings in the DAS configuration.
Every additional data channel, parameter, number of samples setting etc. and will reduce the maximum amount of data points somewhat. In general, however, the maximum data capacity is divided amongst all channels (max: 20) and parameters (max: 50 per channel).
The DAS will check the amount of available data space and prevent the user from specifying too many records at any given point. If, for example, the DAS memory space can accommodate 375 more data records, the ENTR key will disappear when trying to specify more than that number of records. This check for memory space may also make an upload of an DAS configuration with APICOM or a Terminal program fail, if the combined number of records would be exceeded. In this case, it is suggested to either try from the front panel what the maximum number of records can be or use trial-and-error in designing the DAS script or calculate the number of records using the DAS or APICOM manuals. To set the number of records for one channel from the front panel, press SETUP-DAS-EDIT-ENTR and the following touchscreen button sequence.
From the DATA ACQUISITION menu
(see Section 6.12.2.2)
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1 2, 900
PREV NEXT INS DEL EDIT PRNT EXIT
Exits to the main
Data Acquisition menu
SETUP X.X NAME:CONC
<SET SET> EDIT PRINT EXIT
Press SET> key until…
SETUP X.X
NUMBER OF RECORDS:000
<SET SET> EDIT PRINT EXIT
SETUP X.X EDIT RECOPRDS (DELET DATA)
YES NO
YES will delete all data in this channel.
Toggle buttons to set number of records
(1-99999)
SETUP X.X REPORT PERIODD:DAYS:0
0 0 0 0 0 ENTR EXIT
NO returns to the previous menu.
ENTR accepts the new setting and returns to the previous menu.
EXIT ignores the new setting and returns to the previous menu.
Teledyne Analytical Instruments 84
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.2.8. RS-232 Report Function
The GFC 7000TA DAS can automatically report data to the communications ports, where they can be captured with a terminal emulation program or simply viewed by the user.
To enable automatic COM port reporting, follow the instruction shown in Section 6.7.2.2 then press:
From the DATA ACQUISITION menu
(see Section 6.7.2.2)
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL EDIT PRNT EXIT
Exits to the main
Data Acquisition menu
SETUP X.X NAME:CONC
<SET SET> EDIT PRINT
Press SET> key until…
EXIT
SETUP X.X RS-232 REPORT: OFF
<SET SET> EDIT PRINT EXIT
Toggle to turn reporting ON or OFF
SETUP X.X RS-232 REPORT: OFF
OFF ENTR EXIT
ENTR accepts the new setting and returns to the previous menu.
EXIT ignores the new setting and returns to the previous menu.
6.7.2.9. Compact Report
When enabled, this option avoids unnecessary line breaks on all RS-232 reports. Instead of reporting each parameter in one channel on a separate line, up to five parameters are reported in one line.
6.7.2.10. Starting Date
This option allows to specify a starting date for any given channel in case the user wants to start data acquisition only after a certain time and date. If the Starting Date is in the past, the DAS ignores this setting.
Teledyne Analytical Instruments 85
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.2.11. Disabling/Enabling Data Channels
Data channels can be temporarily disabled, which can reduce the read/write wear on the disk-on-chip.
The ALL_01 channel of the GFC 7000TA, for example, is disabled by default.
To disable a data channel, follow the instruction shown in Section 6.7.2.2 then press:
From the DATA ACQUISITION menu
(see Section 6.7.2.2)
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL
EDIT
PRNT EXIT
Exits to the main
Data Acquisition menu
SETUP X.X NAME:CONC
<SET
SET>
EDIT PRINT EXIT
Toggle to turn channel ON or OFF
Press SET> key until…
SETUP X.X
CHANNEL ENABLE:ON
<SET SET>
EDIT
PRINT EXIT
SETUP X.X
CHANNEL ENABLE:ON
OFF ENTR EXIT
ENTR accepts the new setting and returns to the previous menu.
EXIT
ignores the new setting and returns to the previous menu.
Teledyne Analytical Instruments 86
Operating Instructions
6.7.2.12. HOLDOFF Feature
Model GFC7000TA Carbon Dioxide Analyzer
The DAS HOLDOFF feature allows to prevent data collection during calibrations and during the
DAS_HOLDOFF period enabled and specified in the VARS (Section 6.12). To enable or disable the
HOLDOFF, follow the instruction shown in Section 6.7.2.2 then press:
From the DATA ACQUISITION menu
(see Section 6.7.2.2)
Edit Data Channel Menu
SETUP X.X 0) CONC: ATIMER, 1, 900
PREV NEXT INS DEL
EDIT
PRNT EXIT
Exits to the main
Data Acquisition menu
SETUP X.X NAME:CONC
<SET
SET>
EDIT PRINT EXIT
Press SET> key until…
SETUP X.X CAL HOLD OFF:ON
SET>
EDIT
PRINT EXIT
Toggle to turn HOLDOFF
ON or OFF ON
SETUP X.X
CAL HOLD OFF:ON
ENTR EXIT
ENTR
accepts the new setting and returns to the previous menu.
EXIT ignores the new setting and returns to the previous menu.
Teledyne Analytical Instruments 87
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.7.3. Remote DAS Configuration
Editing channels, parameters and triggering events as described in this can be performed via the
APICOM remote control program using the graphic interface shown in Figure 6-5. Refer to Section 6.15 for details on remote access to the GFC 7000TA analyzer.
Figure 6-5: APICOM User Interface for DAS Configuration
Once a DAS configuration is edited (which can be done offline and without interrupting DAS data collection), it is conveniently uploaded to the instrument and can be stored on a computer for later review, alteration or documentation and archival. Refer to the APICOM manual for details on these procedures.
The APICOM user manual (Teledyne Instruments part number 039450000) is included in the APICOM installation file, which can be downloaded at http://www.teledyne-api.com/software/apicom/. It is recommended that you start by downloading the default DAS configuration, getting familiar with its command structure and syntax conventions, and then altering a copy of the original file offline before uploading the new configuration.
CAUTION
Whereas the editing, adding and deleting of DAS channels and parameters of one channel through the front-panel touchscreen can be done without affecting the other channels, uploading an DAS configuration script to the analyzer through its communication ports will erase all data, parameters and channels by replacing them with the new DAS configuration. Backup of data and the original DAS configuration is advised before attempting any DAS changes.
Teledyne Analytical Instruments 88
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8. SETUP RNGE: Analog Output Reporting Range
Configuration
The analyzer has three active analog output signals, accessible through a connector on the rear panel.
ANALOG OUT
CO
2
concentration outputs
Test Channel
Not Used
A1 A2 A3 A4
+ - + - + - + -
LOW range when DUAL mode is selected
HIGH range when DUAL mode is selected
Figure 6-6: Analog Output Connector Pin Out
All three outputs can be configured either at the factory or by the user for full scale outputs of 0.1 VDC,
1VDC, 5VDC or 10VDC. Additionally A1 and A2 may be equipped with optional 0-20 mADC current loop drivers and configured for any current output within that range (e.g. 0-20, 2-20, 4-20, etc.). The user may also adjust the signal level and scaling of the actual output voltage or current to match the input requirements of the recorder or data logger (See Section 6.13.4).
The A1 and A2 channels output a signal that is proportional to the CO
2
concentration of the sample gas.
Several modes are available which allow them to operate independently or be slaved together (See
Section 6.7). The user may also select between a variety of reporting range spans (See Sections 6.8.3,
6.8.4 and 6.8.5).
EXAMPLE:
A1 OUTPUT: Output Signal = 0-5 VDC representing 0-1000 ppm concentration values
A2 OUTPUT: Output Signal = 0 – 10 VDC representing 0-500 ppm concentration values.
Output A3 is only active if the O
2 currently measured O
2
sensor option is installed. In this case a signal representing the
concentration is output on this channel.
The output, labeled A4 is special. It can be set by the user (See Section 6.13.9) to output several of the test functions accessible through the <TST TST> keys of the units sample display.
Teledyne Analytical Instruments 89
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8.1. Physical Range versus Analog Output Reporting Ranges
Functionally, the Gas Filter Correlation CO
2
Analyzer has one hardware Physical Range that is capable of determining CO
2
concentrations between 50 ppm and 2,000 ppm. This architecture improves reliability and accuracy by avoiding the need for extra, switchable, gain-amplification circuitry. Once properly calibrated, the analyzer’s front panel will accurately report concentrations along the entire span of its 50 ppm and 2,000 ppm physical range.
Because, most applications use only a small part of the analyzer’s physical range, the width of the Model
GFC 7000TA’s physical range can create data resolution problems for most analog recording devices.
For example, in an application where the expected concentration of CO
2
is typically less than 500 ppm, the full scale of expected values is only 25% of the instrument’s 2,000 ppm physical range. Unmodified, the corresponding output signal would also be recorded across only 25% of the range of the recording device.
The GFC 7000TA solves this problem by allowing the user to select a scaled reporting range for the analog outputs that only includes that portion of the physical range relevant to the specific application.
Only the reporting range of the analog outputs is scaled, the physical range of the analyzer and the readings displayed on the front panel remain unaltered.
6.8.2. Reporting Range Modes
The GFC 7000TA provides three analog output range modes to choose from.
(SNGL) mode sets a single maximum range for the analog output. If single range is selected (See Section 6.78.3) both outputs are slaved together and will represent the same measurement span (e.g. 0-50 ppm), however their electronic signal levels may be configured for different ranges (e.g. 0-10 VDC vs. 0-.1 VDC – See Section 6.9.4.1).
Dual range (DUAL) allows the A1 and A2 outputs to be configured with different measurement spans (See Section 6.8.4) as well as separate electronic signal levels (See Section 6.9.4.1).
Auto range (AUTO) mode gives the analyzer to ability to output data via a low range and high range.
When this mode is selected (See Section 6.8.5) the GFC 7000TA will automatically switch between the two ranges dynamically as the concentration value fluctuates.
Range status is also output via the external digital I/O status outputs (See Section 6.15.1.1).
Teledyne Analytical Instruments 90
Operating Instructions
To select the Analog Output Range Type press:
Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SAMPLE
ENTER SETUP PASS : 818
8 1 8 ENTR EXIT
SETUP X.X
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X
MODE SET UNIT
RANGE CONTROL MENU
EXIT
SETUP X.X RANGE MODE:
SNGL DUAL AUTO
SNGL
ENTR EXIT
EXIT Returns to the Main
SAMPLE Display
Only one of the range modes may be active at any time.
Go To
Section
6.7.3
Go To
Section
6.7.4
Go To
Section
6.7.5
NOTE
Upper span limit setting for the individual range modes are shared. Resetting the span limit in one mode also resets the span limit for the corresponding range in the other modes as follows:
Range1 Low
Teledyne Analytical Instruments 91
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8.3. Single Range Mode (SNGL)
This is the default reporting range mode for the analyzer. In single range mode both A1 and A2 are set to the same reporting range. This reporting range can be any value between 50 ppm and 2 000 ppm.
While the two outputs always have the same reporting range, the span, signal offset and scaling of their electronic signals may be configured for differently (e.g., A1 = 0-10 V; A2 = 0-0.1 V). See Section 6.13.4 for instructions on adjusting these parameters.
To select SNGL range mode and to set the upper limit of the range, press:
SAMPLE* RANGE = 500.000 PPM CO2 X.XXX
< TST TST > CAL SETUP
SETUP C.3 RANGE MODE: SNGL
SNGL DUAL AUTO ENTR EXIT
SETUP C.3 PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP C.3
MODE SET UNIT
RANGE CONTROL MENU
EXIT
SETUP C.3
MODE SET UNIT
RANGE CONTROL MENU
EXIT
SETUP C.3 RANGE MODE:
SNGL DUAL AUTO
SNGL
ENTR EXIT
SETUP C.3 RANGE: 500.0 Conc
0 0 5 0 0 .0
ENTR EXIT
SETUP C.3
MODE SET UNIT
RANGE CONTROL MENU
EXIT
EXIT x 2 returns to the main
SAMPLE display
Teledyne Analytical Instruments 92
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8.4. Dual Range Mode (DUAL)
Selecting Dual Range mode allows the A1 and A2 outputs to be configured with different reporting ranges. The analyzer software calls these two ranges low and high. The low range setting corresponds with the analog output labeled A1 on the Rear Panel of the instrument. The high Range Setting corresponds with the A2 output. While the software names these two ranges low and high, they do not have to be configured that way. For example: The low range can be set for a span of 0-1000 ppm while the high range is set for 0-500 ppm.
In DUAL range mode the RANGE test function displayed on the front panel will be replaced by two separate functions:
RANGE1: The range setting for the A1 output.
RANGE2: The range setting for the A2 output.
To set the ranges press following keystroke sequence
.
SETUP X.X RANGE MODE:
SNGL DUAL AUTO
DUAL
ENTR EXIT
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X
RANGE CONTROL MENU
MODE SET UNIT EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X RANGE CONTROL MENU
SET UNIT EXIT
SETUP X.X LOW RANGE : 500.0 Conc
0 0 1 0 0 .0 ENTR EXIT
Toggle the numeral buttons to set the upper limit of each range. SETUP X.X
HIGH RANGE: 500.0 Conc
0 0 5 0 0 .0
ENTR EXIT
SETUP X.X RANGE MODE:
SNGL DUAL AUTO
SNGL
ENTR EXIT
SETUP X.X RANGE CONTROL MENU
MODE SET UNIT EXIT
EXIT Returns to the Main
SAMPLE Display
When the instrument’s range mode is set to DUAL the concentration field in the upper right hand corner of the display alternates between displaying the low range value and the high range value. The concentration currently being displayed is identified as follows: C1 = Low (or A1) and C2 = High (or A2).
NOTE
In DUAL range mode the LOW and HIGH ranges have separate slopes and offsets for computing CO
2
concentration.
The two ranges must be independently calibrated.
Teledyne Analytical Instruments 93
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8.5. Auto Range Mode (AUTO)
In AUTO range mode, the analyzer automatically switches the reporting range between two user-defined ranges (low and high). The unit will switch from low range to high range when the CO exceeds 98% of the low range span. The unit will return from high range back to low range once both the
CO
2
concentration falls below 75% of the low range span.
2
concentration
In AUTO Range mode the instrument reports the same data in the same range on both the A1 and A2 outputs and automatically switches both outputs between ranges as described above. Also, the RANGE test function displayed on the front panel will automatically switch to show which range is in effect.
The high/low range status is also reported through the external, digital status outputs (Section 6.15.1.1).
To set individual ranges press the following keystroke sequence.
SETUP X.X RANGE MODE:
SNGL DUAL AUTO
AUTO
ENTR EXIT
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X RANGE CONTROL MENU
MODE SET UNIT EXIT
EXIT x 2 returns to the main
SAMPLE display
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X RANGE CONTROL MENU
MODE SET UNIT EXIT
SETUP X.X RANGE MODE:
SNGL DUAL AUTO
SNGL
ENTR EXIT
SETUP X.X LOW RANGE: 500.0 Conc
0 0 5 0 0 .0 ENTR EXIT
SETUP X.X HIGH RANGE: 500.0 Conc
0 0 5 0 0 .0
ENTR EXIT
Toggle the numeral buttons to set the
LOW and HIGH range value.
ENTR accepts the new setting, EXIT ignores the new setting.
CAUTION
In AUTO range mode the LOW and HIGH ranges have separate slopes and offsets for computing CO2 concentration.
The two ranges must be independently calibrated.
NOTE
Avoid accidentally setting the low range of the instrument with a higher span limit than the high range. This will cause the unit to stay in the low reporting range perpetually and defeat the function of the AUTO range mode.
Teledyne Analytical Instruments 94
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8.6. Range Units
The GFC 7000TA can display concentrations in parts per billion (10
(10
6
mols per mol, PPM), micrograms per cubic meter (µg/m
3
MG ) or percent (volume CO
2
9 mols per mol, PPB), parts per million
, UG), milligrams per cubic meter (mg/m
3
/volume sample gas, %). Changing units affects all of the display, analog outputs, COM port and DAS values for all reporting ranges regardless of the analyzer’s range mode.
,
NOTE
Concentrations displayed in mg/m3 and ug/m3 use 0C, 760 mmHg for Standard
Temperature and Pressure (STP). Consult your local regulations for the STP used by your agency.
Conversion factors from volumetric to mass units are:
CO
2
: ppb x 1.96 = µg/m3; ppm x 1.96 = mg/m3
To change the concentration units:
SAMPLE RANGE = 500.00 PPB CO2=X.XXX
< TST TST > CAL SETUP
Select the preferred concentration unit.
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X
MODE SET UNIT
RANGE CONTROL MENU
EXIT
SETUP X.X CONC UNITS: PPM
PPM PPB UGM MGM % ENTER EXIT
SETUP X.X CONC UNITS: %
PPM PPB UGM MGM % ENTER EXIT
EXIT
returns to the main menu.
ENTR accepts the new unit,
EXIT returns to the SETUP menu.
NOTE
Once the units of measurement have been changed the unit MUST be recalibrated, as the “expected span values” previously in effect will no longer be valid. Simply entering new expected span values without running the entire calibration routine is not sufficient.
Teledyne Analytical Instruments 95
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.8.7. Dilution Ratio
The dilution ratio is a software option that allows the user to compensate for any dilution of the sample gas before it enters the sample inlet. Using the dilution ratio option is a 4-step process:
1. Select reporting range units: Follow the procedure in Section 6.8.6.
2. Select the range: Use the procedures in Sections 6.8.2 – 6.8.5. Make sure that the SPAN value entered is the maximum expected concentration of the undiluted calibration gas and that the span gas is either supplied through the same dilution inlet system as the sample gas or has an appropriately lower actual concentration. For example, with a dilution set to 100, a 10 ppm gas can be used to calibrate a 1000 ppm sample gas if the span gas is not routed through the dilution system. On the other hand, if a 1000 ppm span gas is used, it needs to pass through the same dilution steps as the sample gas.
3. Set the dilution factor as a gain (e.g., a value of 20 means 20 parts diluting gas and 1 part of sample gas):
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP C.3 PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
DIL only appears if the dilution ratio option has been installed
SETUP C.3 RANGE CONTROL MENU
MODE SET UNIT DIL EXIT
Toggle these buttons to set the dilution factor.
This is the number by which the analyzer will multiply the CO through the reaction cell.
2 concentrations of the gas passing
SETUP C.3
DIL FACTOR: 1.0 GAIN
0 0 0 1 .0
ENTR EXIT
SETUP C.3 DIL FACTOR: 20.0 GAIN
0 0 2 0 .0 ENTR EXIT
EXIT ignores the new setting.
ENTR accepts the new setting.
The analyzer multiplies the measured gas concentrations with this dilution factor and displays the result.
NOTE
Once the above settings have been entered, the instrument needs to be recalibrated using one of the methods discussed in Section 7.
Teledyne Analytical Instruments 96
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.9. SETUP PASS: Password Feature
The GFC 7000TA provides password protection of the calibration and setup functions to prevent unauthorized adjustments. When the passwords have been enabled in the PASS menu item, the system will prompt the user for a password anytime a password-protected function is requested.
There are three levels of password protection, which correspond to operator, maintenance, and configuration functions. Each level allows access to all of the functions in the previous level.
Table 6-9: Password Levels
PASSWORD
No password
818
LEVEL
Operator
Maintenance
MENU ACCESS ALLOWED
TEST, MSG, CLR
CAL, CALZ, CALS
929 Configuration SETUP, VARS, DIAG
To enable or disable passwords, press the following keystroke sequence:
Teledyne Analytical Instruments 97
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Example: If all passwords are enabled, the following keypad sequence would be required to enter the
SETUP menu:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP prompts for password number
See Table 6-8 for
Passwords and Levels
SAMPLE ENTER SETUP PASS: 0
0 0 0 ENTR EXIT
Press individual buttons to set numbers
SAMPLE ENTER SETUP P ASS: 0
8 1 8 ENTR EXIT
Example: this password enables the
SETUP mode
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
Note that the instrument still prompts for a password when entering the VARS and DIAG menus, even if passwords are disabled, but it displays the default password (818) upon entering these menus. The user only has to press ENTR to access the password-protected menus but does not have to enter the required number code.
Teledyne Analytical Instruments 98
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.10. SETUP CLK: Setting the Internal Time-of-Day Clock
The GFC 7000TA has a time of day clock that supports the AutoCal timer, time of day TEST function, and time stamps on most COM port messages. To set the time-of-day, press:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
Enter Current
Time-of-Day
SETUP X.X
1 2 : 0 0
TIME: 12:00
ENTR EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS
CLK
MORE EXIT
SETUP X.X
TIME DATE
TIME-OF-DAY CLOCK
Enter Current
Date-of-Year
EXIT
SETUP X.X
0 1 JAN 0 2
DATE: 01-JAN-02
ENTR EXIT
SETUP X.X3
1 2 : 0 0
TIME:
12:00
SETUP X.X DATE:
0 1 JAN 0 2
01-JAN-02
ENTR
EXIT
ENTR
EXIT
SETUP X.X
TIME DATE
TIME-OF-DAY CLOCK
SETUP X.X
PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE
EXIT
EXIT
EXIT returns to the main
SAMPLE
display
Teledyne Analytical Instruments 99
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
In order to compensate for CPU clocks which run faster or slower, you can adjust a variable called
CLOCK_ADJ to speed up or slow down the clock by a fixed amount every day. To change this variable, press:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUPX.X 1 ) CONC_PRECISION = 3
PREV NEXT JUMP EDIT PRNT EXIT
SETUP X.X
PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
Continue to press NEXT until …
SETUP X.X
SECONDARY SETUP MENU
COMM VARS DIAG EXIT
SETUP X.X 0 ) DAS_HOLD_OFF=15.0 Minutes
NEXT
JUMP EDIT PRNT EXIT
SETUP X.X 4) CLOCK_ADJ=0 Sec/Day
PREV JUMP
EDIT
PRNT EXIT
SETUP X.X
+ 0 0
CLOCK_ADJ:
0 Sec/Day
ENTR
EXIT
Enter sign and number of seconds per day the clock gains (-) or loses (+).
SETUP X.X 4) CLOCK_ADJ=0 Sec/Day
PREV NEXT JUMP EDIT PRNT EXIT
3x EXIT returns to the main SAMPLE display
Teledyne Analytical Instruments 100
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11. SETUP MORE COMM: Using the Analyzer’s
Communication Ports
The GFC 7000TA is equipped with an Ethernet port, a USB port and two serial communication (COMM) ports located on the rear panel (Figure 3-2). Both com ports operate similarly and give the user the ability to communicate with, issue commands to, and receive data from the analyzer through an external computer system or terminal.
By default, both com ports operate on the RS-232 protocol.
The RS232 port (used as COM1) can also be configured to operate in single or RS-232 multidrop mode (option 62; See Section 5.5.2 and 6.11.7).
The COM2 port can be configured for standard RS-232 operation or half-duplex RS-485 communication (For RS-485 communication, please contact the factory).
A code-activated switch (CAS), can also be used on either port to connect typically between 2 and 16 send/receive instruments (host computer(s) printers, data loggers, analyzers, monitors, calibrators, etc.) into one communications hub. Contact Teledyne Instruments sales for more information on CAS systems.
6.11.1. Analyzer ID
Each type of Teledyne Instruments analyzer is configured with a default ID code. The default ID code for all GFC 7000TA analyzers is 360. The ID number is only important if more than one analyzer is connected to the same communications channel such as when several analyzers are on the same
Ethernet LAN (See Section 6.11.6); in a RS-232 multidrop chain (See Section 6.11.7) or operating over a
RS-485 network. If two analyzers of the same model type are used on one channel, the ID codes of one or both of the instruments needs to be changed.
To edit the instrument’s ID code, press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X COMMUNICATIONS MENU
ID INET COM1 EXIT
Toggle these keys to cycle through the available character set:
0-9
SETUP X. MACHINE ID: 360 ID
0 2 0 0 ENTR EXIT
ENTR accepts the new settings
EXIT ignores the new settings
The ID number is only important if more than one analyzer is connected to the same communications channel (e.g., a multi-drop setup). Different models of Teledyne Instruments analyzers have different default ID numbers, but if two analyzers of the same model type are used on one channel (for example, two GFC 7000TA’s), the ID of one instrument needs to be changed.
Teledyne Analytical Instruments 101
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
The ID can also be used for to identify any one of several analyzers attached to the same network but situated in different physical locations.
6.11.2. COM Port Default Settings
Received from the factory, the analyzer is set up to emulate a DCE or modem, with pin 3 of the DB-9 connector designated for receiving data and pin 2 designated for sending data.
COM1: RS-232 (fixed) DB-9 male connector. o
Baud rate: 19200 bits per second (baud). o
Data Bits: 8 data bits with 1 stop bit. o
Parity: None.
COM2: RS-232 (configurable), DB-9 female connector. o
Baud rate: 115000 bits per second (baud). o
Data Bits: 8 data bits with 1 stop bit. o
Parity: None.
NOTE
Cables that appear to be compatible because of matching connectors may incorporate internal wiring that make the link inoperable. Check cables acquired from sources other than Teledyne Instruments for pin assignments before using.
In its default configuration, the GFC 7000TA analyzer has two available RS-232 Com ports accessible via
2 DB-9 connectors on the back panel of the instrument. The COM1 connector is a male DB-9 connector and the COM2 is a female DB9 connector.
Teledyne Analytical Instruments 102
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Figure 6-7: Rear Panel Connector Pin-Outs for COM1 & COM2 in RS-232 Mode
The signals from these two connectors are routed from the motherboard via a wiring harness to two 10pin connectors on the CPU card, J11 and J12.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Figure 6-8: CPU Connector Pin-Outs for COM1 & COM2 in RS-232 Mode
Teledyne Instruments offers two mating cables, one of which should be applicable for your use.
Part number WR000077, a DB-9 female to DB-9 female cable, 6 feet long. Allows connection of
COM1 with the serial port of most personal computers. Also available as Option 60 (See Section
5.5.1).
Part number WR000024, a DB-9 female to DB-25 male cable. Allows connection to the most common styles of modems (e.g. Hayes-compatible) and code activated switches.
Both cables are configured with straight-through wiring and should require no additional adapters.
To assist in properly connecting the serial ports to either a computer or a modem, there are activity indicators just above the RS-232 port. Once a cable is connected between the analyzer and a computer or modem, both the red and green LEDs should be on. If the lights for COM 1 are not lit, use small switch on the rear panel to switch it between DTE and DCE modes (See
Section 6.11.4). If both LEDs are still not illuminated, check the cable for proper wiring.
Teledyne Analytical Instruments 104
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.3. RS-485 Configuration of COM2
As delivered from the factory, COM2 is configured for RS-232 communications. To configure this port for
RS-485 communication, please contact the factory. If COM2 is configured for RS-485, the USB com port is no longer enabled.
6.11.4. DTE and DCE Communication
RS-232 was developed for allowing communications between data terminal equipment (DTE) and data communication equipment (DCE). Basic terminals always fall into the DTE category whereas modems are always considered DCE devices. The difference between the two is the pin assignment of the Data
Receive and Data Transmit functions. DTE devices receive data on pin 2 and transmit data on pin 3;
DCE devices receive data on pin 3 and transmit data on pin 2.
To allow the analyzer to be used with terminals (DTE), modems (DCE) and computers (which can be either), a switch mounted below the serial ports on the rear panel allows the user to switch between the two functions.
Teledyne Analytical Instruments 105
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.5. COM Port Communication Modes
Each of the analyzer’s serial ports can be configured to operate in a number of different modes, listed in
Table 6-10 which can be combined by adding the mode ID numbers. For example, quiet mode, computer mode and internet-enabled mode would carry a combined mode ID of 11, the standard configuration on the GFC 7000TA COM2 port. Note that each COM port needs to be configured independently.
Table 6-10: Com Port Communication Modes
MODE
1
ID
QUIET
COMPUTER
SECURITY
HESSEN
PROTOCOL
1
2
4
16
DESCRIPTION
Quiet mode suppresses any feedback from the analyzer (DAS reports, and warning messages) to the remote device and is typically used when the port is communicating with a computer program such as APICOM. Such feedback is still available but a command must be issued to receive them.
Computer mode inhibits echoing of typed characters and is used when the port is communicating with a computer program, such as APICOM.
When enabled, the serial port requires a password before it will respond. The only command that is active is the help screen (? CR).
The Hessen communications protocol is used in some European countries. Teledyne
Instruments part number 02252 contains more information on this protocol.
E, 7, 1
RS-485
MULTIDROP
PROTOCOL
ENABLE
MODEM
ERROR
CHECKING
2
2048
1024
32
64
128
When turned on this mode switches the com port settings
from
No parity; 8 data bits; 1 stop bit to
Even parity; 7 data bits; 1 stop bit
Configures the COM2 Port for RS-485 communication. RS-485 mode has precedence over multidrop mode if both are enabled.
Multidrop protocol allows a multi-instrument configuration on a single communications channel. Multidrop requires the use of instrument IDs.
Enables to send a modem initialization string at power-up. Asserts certain lines in the
RS-232 port to enable the modem to communicate.
Fixes certain types of parity errors at certain Hessen protocol installations.
XON/XOFF
HANDSHAKE
2
256
Disables XON/XOFF data flow control also known as software handshaking.
HARDWARE
HANDSHAKE
8
Enables CTS/RTS style hardwired transmission handshaking. This style of data transmission handshaking is commonly used with modems or terminal emulation protocols as well as by Teledyne Instrument’s APICOM software.
Improves data transfer rate when on of the com ports.
HARDWARE
FIFO
2
512
COMMAND
PROMPT
4096
Enables a command prompt when in terminal mode.
1
Modes are listed in the order in which they appear in the
SETUP
MORE com COM[1 OR 2] MODE menu
2
The default sting for this feature is ON. Do not disable unless instructed to by Teledyne Instruments Customer Service personnel.
Teledyne Analytical Instruments 106
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Press the following touchscreen buttons to select a communication mode for one of the com Ports, such as the following example where HESSEN PROTOCOL mode is enabled:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
Select which COMM port to configure
The sum of the mode
IDs of the selected modes is displayed here
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X COMMUNICATIONS MENU
ID INET COM1 COM2 EXIT
SETUP X.X COM1 MODE:0
SET> EDIT EXIT
SETUP X.X COM1 QUIET MODE: OFF
NEXT OFF ENTR EXIT
EXIT returns to the previous menu
Use PREV and NEXT to move between available modes.
A mode is enabled by toggling the ON/OFF button.
Continue pressing next until …
SETUP X.X COM1 HESSEN PROTOCOL : OFF
PREV NEXT OFF ENTR EXIT
SETUP X.X COM1 HESSEN PROTOCOL : ON
PREV NEXT ON ENTR EXIT
ENTR accepts the new settings
EXIT ignores the new settings
Teledyne Analytical Instruments 107
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.6. Remote Access via the Ethernet
When using the Ethernet interface, the analyzer can be connected to any standard 10BaseT or 100Base
T Ethernet network via low-cost network hubs, switches or routers. The interface operates as a standard
TCP/IP device on a user selectable port, which otherwise defaults to port 3000. This allows a remote computer to connect through the internet to the analyzer using APICOM, terminal emulators or other programs.
The Ethernet connector has two LEDs that are on the connector itself, indicating its current operating status.
Table 6-11: Ethernet Status Indicators
LED Function amber (link) On when connection to the LAN is valid. green (activity Flickers during any activity on the LAN.
6.11.6.1. Configuring the Ethernet Interface using DHCP
The Ethernet option for your analyzer uses Dynamic Host Configuration Protocol (DHCP) to automatically configure its interface with your LAN. This requires your network servers also be running DHCP. The analyzer will do this the first time you turn the instrument on after it has been physically connected to your network. Once the instrument is connected and turned on it will appear as an active device on your network without any extra set up steps or lengthy procedures.
Teledyne Analytical Instruments 108
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Table 6-12: LAN/Internet Configuration Properties
DHCP
INSTRUMENT
IP ADDRESS
GATEWAY IP
ADDRESS
SUBNET MASK
TCP PORT
1
ON
0.0.0.0
0.0.0.0
3000
DESCRIPTION
This displays whether the DHCP is turned ON or OFF.
Press EDIT and toggle ON for automatic configuration after first consulting network administrator. (
This string of four packets of 1 to 3 numbers each (e.g.
192.168.76.55.) is the address of the analyzer itself.
Can only be edited when DHCP is set to OFF.
A string of numbers very similar to the Instrument IP address (e.g. 192.168.76.1.) that is the address of the computer used by your LAN to access the Internet.
Can only be edited when DHCP is set to OFF.
Also a string of four packets of 1 to 3 numbers each (e.g.
255.255.252.0) that identifies the LAN to which the device is connected.
All addressable devices and computers on a LAN must have the same subnet mask. Any transmissions sent to devices with different subnets are assumed to be outside of the LAN and are routed through the gateway computer onto the Internet.
This number defines the terminal control port by which the instrument is addressed by terminal emulation software, such as Internet or Teledyne’s APICOM.
HOST NAME
T100
The name by which your analyzer will appear when addressed from other computers on the LAN or via the
Internet. To change, see Section 6.11.6.3.
1
Do not change the setting for this property unless instructed to by Teledyne Customer Service personnel.
NOTE
It is a good idea to check these settings the first time you power up your analyzer after it has been physically connected to the LAN/Internet to make sure that the
DHCP has successfully downloaded the appropriate information from you network server(s).
If the gateway IP, instrument IP and the subnet mask are all zeroes (e.g.
“0.0.0.0”), the DCHP was not successful.
You may have to manually configure the analyzer’s Ethernet properties.
See your network administrator.
Teledyne Analytical Instruments 109
Operating Instructions
To view the above properties, press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
Model GFC7000TA Carbon Dioxide Analyzer
SETUP X.X DHCP: ON
SET> EDIT EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG EXIT
SETUP X.X COMMUNICATIONS MENU
ID INET COM1 EXIT
SAMPLE ENTER SETUP PASS : 818
8 1 8 ENTR EXIT
From this point on,
EXIT returns to
COMMUNICATIONS
MENU
SETUP X.X INST IP: 0.0.0.0
<SET SET> EXIT
SETUP X.X GATEWAY IP: 0.0.0.0
<SET SET> EXIT
SETUP X.X SUBNET MASK: 0.0.0.0
<SET SET> EXIT
EDIT Key
Disabled
SETUP X.X TCP PORT: 3000
<SET SET> EDIT EXIT
SETUP X.X HOSTNAME: T360
<SET EDIT EXIT
Do not alter unless directed to by Teledyne
Instruments Customer
Service personnel
Teledyne Analytical Instruments 110
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.6.2. Manually Configuring the Ethernet (Static IP Address)
To configure Ethernet communication manually:
1. Connect a cable from the analyzer’s Ethernet port to a Local Area Network (LAN) or Internet port.
2. From the analyzer’s front panel touchscreen, access the Communications Menu as shown below, turning DHCP mode to OFF.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Next, refer to Table 6-12 for the default Ethernet configuration settings and configure the INSTRUMENT
IP addresses by pressing:
Teledyne Analytical Instruments 112
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.6.3. Changing the Analyzer’s HOSTNAME
The HOSTNAME is the name by which the analyzer appears on your network. The default name for all
Teledyne Instruments Model GFC 7000TA analyzers is GFC 7000TA. To change this name (particularly if you have more than one Model GFC 7000TA analyzer on your network), press.
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
SETUP X.X DHCP: ON
SET>
EDIT
EXIT
Continue pressing SET> UNTIL … SETUP X.X
PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
SETUP X.X
SECONDARY SETUP MENU
COMM
VARS DIAG ALRM EXIT
SETUP X.X
HOSTNAME:
<SET
EDIT
EXIT
SETUP X.X
COMMUNICATIONS MENU
ID INET COM1 COM2 EXIT
SAMPLE
ENTER SETUP PASS : 818
8 1 8 ENTR
EXIT
SETUP X.X HOSTNAME:
<CH CH> INS DEL [?] ENTR EXIT
Use these buttons (See Table 6-
19) to edit HOSTNAME
SETUP X.X
HOSTNAME: T360-FIELD1
<SET
EDIT
EXIT
SETUP X.X INITIALIZING INET 0%
…
INITIALIZING INET 100%
SETUP X.X INITIALIZATION SUCCEEDED SETUP X.X INITIALIZATION FAILED
SETUP X.X
COMMUNICATIONS MENU
ID
INET
COM1 COM2 EXIT
Table 6-13: Internet Configuration Touchscreen Functions
Contact your IT Network
Administrator
BUTTON FUNCTION
<CH
CH>
INS
DEL
Moves the cursor one character to the left.
Moves the cursor one character to the right.
Inserts a character before the cursor location.
Deletes a character at the cursor location.
[?] Press this button to cycle through the range of numerals and characters available for insertion. 0-9, A-Z, space ’ ~ ! # $ % ^ & * ( ) - _ = +[ ] { } < >\ | ; : , . / ?
Accepts the new setting and returns to the previous menu. ENTR
EXIT Ignores the new setting and returns to the previous menu.
Some buttons only appear as applicable.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.7. Multidrop RS-232 Set Up
The RS-232 multidrop consists of a printed circuit assembly that is seated on the analyzer’s CPU card
(see Figures 6-10 and 6-13) and is connected to the CPU and the motherboard. This PCA includes all circuitry required to enable your analyzer for multidrop operation. It converts the instrument’s RS232 port to multidrop configuration allowing up to eight analyzers to be connected the same I/O port of the host computer.
Because both of the DB9 connectors on the analyzer’s back panel are needed to construct the multidrop chain, COM2 is no longer available for separate RS-232 or RS-485 operation; however, the USB com port is available.
Figure 6-9: Multidrop/LVDS PCA Seated on CPU
Each analyzer in the multidrop chain must have:
One Teledyne Instruments option 62 installed.
One 6’ straight-through, DB9 male DB9 Female cable (Teledyne Instruments P/N WR0000101) is required for each analyzer.
To set up the network, for each analyzer:
1. With NO power to the instrument, open the rear panel and locate the CPU.
2. On the LVDS card, disconnect the cable that’s connected to J1 and remove the LVDS card from the CPU card.
3. Mount the Multidrop/LVDS card onto the CPU and reconnect the LVDS cable to J1.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
4. Connect a cable between the Multidrop/LVDS card J4 and the motherboard P12.
5. Connect a cable between the Multidrop/LVDS card J3 and the CPU COM1 connector.
6. Close the instrument.
7. Using straight-through, DB9 male DB9 Female cable, interconnect the host and the analyzers as shown in Figure 6-14.
8. BEFORE communicating from the host, power on the instruments and check that the Machine ID code is unique for each (see Section Analyzer ID). On the front panel menu, use
SETUP>MORE>COMM>ID. Note that the default ID is typically the model number; to change the
4-digit identification number, press the button of the digit to be changed)..
NOTE:
Teledyne Instruments recommends setting up the first link, between the Host and the first analyzer and testing it before setting up the rest of the chain.
Host
RS-232 port
KEY:
Female DB9
Male DB9
Analyzer
COM2
RS-232
Analyzer
COM2
RS-232
Analyzer
COM2
RS-232
Last Analyzer
COM2
RS-232
Make Sure
Jumper between
JP2 pins 21
22 is installed.
Figure 6-10: RS232-Multidrop PCA Host/Analyzer Interconnect Diagram
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.8. COM Port Baud Rate
To select the baud rate of one of the COM Ports, press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X
SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
EXIT returns to the previous menu
Select which COM port to configure.
Press SET> until you reach COM1 BAUD
RATE
Use PREV and NEXT to move between available baud rates.
300
1200
4800
9600
19200
38400
57600
115200
SETUP X.X
COMMUNICATIONS MENU
ID INET COM1 COM2 EXIT
SETUP X.X
COM1 MODE:0
SET> EDIT EXIT
EXAMPLE
SETUP X.X COM1 BAUD RATE:19200
<SET SET> EDIT EXIT
SETUP X.X COM1 BAUD RATE:19200
PREV
NEXT ENTR EXIT
SETUP X.X COM1 BAUD RATE:9600
NEXT ON ENTR EXIT
EXIT ignores the new setting
ENTR accepts the new setting
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.11.9. COM Port Testing
The serial ports can be tested for correct connection and output in the com menu. This test sends a string of 256 ‘w’ characters to the selected COM port. While the test is running, the red LED on the rear panel of the analyzer should flicker.
To initiate the test press the following touchscreen button sequence.
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG EXIT
Select which
COM port to test.
SETUP X.X
COMMUNICATIONS MENU
ID INET COM1 COM2 EXIT
SETUP X.X COM1 MODE:0
SET> EDIT EXIT
SETUP X.X COM1 BAUD RATE:19200
<SET SET> EDIT EXIT
SETUP X.X COM1 : TEST PORT
<SET TEST EXIT
SETUP X.X TRANSMITTING TO COM1
<SET TEST EXIT
Test runs automatically
EXIT returns to
COMM menu
Teledyne Analytical Instruments 117
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.12. SETUP MORE VARS: Internal Variables (VARS)
The GFC 7000TA has several-user adjustable software variables, which define certain operational parameters. Usually, these variables are automatically set by the instrument’s firmware, but can be manually re-defined using the VARS menu. Table 6-14 lists all variables that are available within the 818 password protected level.
Table 6-14: Variable Names (VARS) Revision B.3
NO. VARIABLE DESCRIPTION
ALLOWED
VALUES
Changes the internal data acquisition system (DAS) hold-off time, which is the duration when data are not stored in the
DAS because the software considers the data to be questionable. That is the case during warm-up or just after the instrument returns from one of its calibration modes to
SAMPLE mode. DAS_HOLD_OFF can be disabled entirely in each DAS channel.
Can be between 0.5 and 20 minutes
Default=15 min.
Allows the user to set the number of significant digits to the right of the decimal point display of concentration and stability values.
AUTO, 1, 2, 3, 4
Default=AUTO
2 STABIL_GAS
Selects which gas measurement is displayed when the STABIL test function is selected.
Dynamic zero automatically adjusts offset and slope of the
CO
2
response when performing a zero point calibration during an AutoCal (Section 7).
Dynamic span automatically adjusts slope and slope of the
CO
2
response when performing a zero point calibration during an AutoCal (Section 7).
4 DYN_SPAN
Note that the DYN_ZERO and DYN_SPAN features are not allowed for applications requiring EPA equivalency.
Adjusts the speed of the analyzer’s clock. Choose the + too fast.
1 O
2
option is only available in analyzers with O
2
sensor options installed.
CO
2
& O
2
1
ON/OFF
ON/OFF
-60 to +60 s/day
Teledyne Analytical Instruments 118
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To access and navigate the VARS menu, use the following touchscreen button sequence.
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SAMPLE ENTER SETUP PASS : 818
8 1 8 ENTR EXIT
EXIT ignores the new setting.
ENTR accepts the new setting.
SETUP X.X 0 ) DAS_HOLD_OFF=
NEXT JUMP EDIT
15.0 Minutes
PRNT EXIT
SETUP X.X 1) CONC_PRECUISION : 3
PREV NEXT JUMP EDIT PRNT EXIT
SETUP X.X 3 ) DYN_ZERO=ON
PREV NEXT JUMP EDIT PRNT EXIT
SETUP X.X
4) DYN_SPAN=ON
PREV NEXT JUMP EDIT PRNT EXIT
SETUP X.X 5) CLOCK_ADJ=0 Sec/Day
PREV
NEXT
JUMP
EDIT
PRNT EXIT
SETUP X.X 0)DAS_HOLD_OFF=15.0 Minutes
1 5 .0 ENTR EXIT
Toggle each button to change setting
SETUP X.X 1) CONC_PRECUISION : 3
AUTO 0 1 2 3 4 ENTR EXIT
Toggle each button to change setting
SETUP X.X
ON
3) DYN_ZERO=ON
ENTR EXIT
Toggle to change setting
SETUP X.X
ON
4) DYN_SPAN=ON
ENTR EXIT
Toggle to change setting
SETUP X.X 5) CLOCK_ADJ=0 Sec/Day
+ 0 0 ENTR EXIT
Toggle to change setting
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13. SETUP MORE DIAG: Using the Diagnostics
Functions
A series of diagnostic tools is grouped together under the SETUPMOREDIAG menu. As these parameters are dependent on firmware revision (see Menu Tree A-6 in Appendix A). The individual parameters, however, are explained in more detail in the indicated in 6-15. These tools can be used in a variety of troubleshooting and diagnostic procedures and are referred to in many places of the maintenance and trouble-shooting s.
Table 6-15: GFC 7000TA Diagnostic (DIAG) Functions
DIAGNOSTIC FUNCTION AND MEANING
SIGNAL I/O : Allows observation of all digital and analog signals in the instrument. Allows certain digital signals such as valves and heaters to be toggled ON and OFF.
ANALOG OUTPUT : When entered, the analyzer performs an analog output step test. This can be used to calibrate a chart recorder or to test the analog output accuracy.
ANALOG I/O CONFIGURATION : the signal levels of the instruments analog outputs may be calibrated (either individually or as a group). Various electronic parameters such as signal span, and offset are available for viewing and configuration.
ELECTRIC TES T: The analyzer is performing an electric test. This test simulates IR detector signal in a known manner so that the proper functioning of the sync/demod board can be verified.
DARK CALIBRATION : The analyzer is performing a dark calibration procedure. This procedure measures and stores the inherent dc offset of the sync/demod board electronics.
PRESSURE CALIBRATION : The analyzer records the current output of the sample gas pressure sensor. This value is used by the CPU to compensate the CO
2
concentration.
FLOW CALIBRATION : This function is used to calibrate the gas flow output signal. This setting is retained when exiting DIAG.
TEST CHAN OUTPUT : Configures the A4 analog output channel.
Front Panel
Mode Indicator
DIAG I/O
DIAG AOUT
DIAG AIO
6.13.2
6.13.3
6.13.4
DIAG OPTIC 6.13.5
DIAG ELEC
DIAG PCAL
DIAG FCAL
DIAG TCHN
6.13.6
6.13.7
6.13.8
6.13.9
Teledyne Analytical Instruments 120
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.1. Accessing the Diagnostic Features
To access the DIAG functions press the following buttons:
SAMPLE* RANGE = 500.00 PPM CO2 =X.XXX
< TST TST > CAL SETUP
DIAG ANALOG I / O CONFIGURATION
PREV NEXT ENTR EXIT
EXIT returns to the main
SAMPLE display
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
DIAG ELECTRICAL TEST
PREV NEXT ENTR EXIT
EXIT returns to the PRIMARY
SETUP MENU
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
DIAG DARK CALIBRATION
PREV NEXT ENTR EXIT
SAMPLE ENTER SETUP PASS: 818
8 1 8 ENTR EXIT
DIAG PRESSURE CALIBRATION
PREV NEXT ENTR EXIT
From this point forward, EXIT returns to the
SECONDARY
SETUP MENU
DIAG
NEXT
SIGNAL I / O
ENTR EXIT
DIAG ANALOG OUTPUT
PREV NEXT ENTR EXIT
DIAG FLOW CALIBRATION
PREV NEXT ENTR EXIT
DIAG TEST CHAN OUTPUT
PREV NEXT ENTR EXIT
6.13.2. Signal I/O
The signal I/O diagnostic mode allows reviewing and changing the digital and analog input/output functions of the analyzer. See Appendix A-4 for a complete list of the parameters available for review under this menu.
NOTE
Any changes of signal I/O settings will remain in effect only until the signal I/O menu is exited. Exceptions are the ozone generator override and the flow sensor calibration, which remain as entered when exiting.
Teledyne Analytical Instruments 121
Operating Instructions
To enter the signal I/O test mode, press:
Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
DIAG
SIGNAL I / O
PREV NEXT
JUMP
ENTR
EXIT
Use NEXT & PREV to move between signal types.
EXIT returns to the main
SAMPLE display
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
SETUP X.X
SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SAMPLE ENTER SETUP PASS: 818
8 1 8 ENTR
EXIT
DIAG I / O
Test Signals Displayed Here
PREV NEXT
JUMP
PRNT EXIT
EXAMPLE
DIAG I / O
JUMP TO: 12
1 2 ENTR
EXIT
Use JUMP to go directly to a specific signal location
See Appendix A-4 for a complete list of available SIGNALS
EXAMPLE:
Enter 12 to Jump to
12)
ST_CONC_VALID
DIAG I / O ST_CONC_VALID = ON
PREV NEXT JUMP
ON
PRNT
EXIT
Exit to return
to the
DIAG menu
Pressing PRNT will send a formatted printout to the serial port and can be captured with a computer or other output device.
6.13.3. Analog Output Step Test
This test can be used to check the accuracy and proper operation of the analog outputs. The test forces all four analog output channels to produce signals ranging from 0% to 100% of the full scale range in 20% increments. This test is useful to verify the operation of the data logging/recording devices attached to the analyzer.
Teledyne Analytical Instruments 122
Operating Instructions
To begin the Analog Output Step Test press:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
Model GFC7000TA Carbon Dioxide Analyzer
DIAG
NEXT
SIGNAL I / O
ENTR EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
DIAG ANALOG OUTPUT
PREV NEXT ENTR EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X ENTER DIAG PASS: 818
8 1 8 ENTR EXIT
DIAG AOUT
0%
ANALOG OUTPUT
EXIT
Performs analog output step test.
0% - 100%
Exit-Exit returns to the
DIAG menu
DIAG AOUT
[0%]
ANALOG OUTPUT
EXIT
Pressing the “0%” button while performing the test will pause the test at that level. Brackets will appear around the value: example: [20%] Pressing the same button again will resume the test.
6.13.4. Analog I/O Configuration
The analog I/O functions that are available in the GFC 7000TA are:
Table 6-16: DIAG - Analog I/O Functions
Sub Menu Function
AOUTS CALIBRATED:
Shows the status of the analog output calibration (YES/NO) and initiates a calibration of all analog output channels.
CONC_OUT_1 Sets the basic electronic configuration of the A1 analog output (CO
2
). There are three options:
Range: Selects the signal type (voltage or current loop) and full scale level of the output.
REC_OFS: Allows setting a voltage offset (not available when RANGE is set to CURRent loop.
CONC_OUT_2
TEST OUTPUT
AIN CALIBRATED
Auto_CAL: Performs the same calibration as AOUT CALIBRATED, but on this one channel only.
NOTE: Any change to RANGE or REC_OFS requires recalibration of this output.
Same as for CONC_OUT_1 but for analog channel 2 (CO
2
)
Same as for CONC_OUT_1 but for analog channel 4 (TEST)
Shows the calibration status (YES/NO) and initiates a calibration of the analog to digital converter circuit on the motherboard.
XIN1
.
For each of 8 external analog input channels, shows the gain, offset, engineering units, and whether the channel is to show up as a Test function.
.
.
XIN8
Teledyne Analytical Instruments 123
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To configure the analyzer’s three analog outputs, set the electronic signal type of each channel and calibrate the outputs. This consists of:
Selecting an output type (voltage or current, if an optional current output driver has been installed) and the signal level that matches the input requirements of the recording device attached to the channel, See Section 6.13.4.1.
Calibrating the output channel. This can be done automatically or manually for each channel, see
Section 6.13.4.2 and 6.13.4.3.
Adding a bipolar recorder offset to the signal, if required (Section 6.13.4.2.)
In its standard configuration, the analyzer’s outputs can be set for the following DC voltages. Each range is usable from -5% to + 5% of the nominal range.
Table 6-17: Analog Output Voltage Ranges
RANGE
0-0.1 V
0-1 V
MINIMUM OUTPUT
-5 mV
-0.05 V
0-5 V
0-10 V
-0.25 V
-0.5 V
The default offset for all ranges is 0 VDC.
MAXIMUM OUTPUT
+105 mV
+1.05 V
+5.25 V
+10.5 V
Teledyne Analytical Instruments 124
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
The following DC current output limits apply to the current loop modules:
Table 6-18: Analog Output Current Loop Range
RANGE MINIMUM OUTPUT MAXIMUM OUTPUT
0-20 mA 0 mA 20 mA
These are the physical limits of the current loop modules, typical applications use 2-20 or 4-20 mA for the lower and upper limits. Please specify desired range when ordering this option.
The default offset for all ranges is 0 mA.
Pin assignments for the output connector at the rear panel of the instrument are shown in Table 6-19.
ANALOG OUT
A1 A2 A3 A4
+ - + - + - + -
Table 6-19: Analog Output Pin Assignments
PIN
3
4
1
2
ANALOG
OUTPUT
A1
A2
VOLTAGE
SIGNAL
V Out
Ground
V Out
Ground
CURRENT
SIGNAL
I Out +
I Out -
I Out +
I Out -
5
6
A3 1
V Out
Ground
I Out +
I Out -
7 V Out Not used
A4
8 Ground
1 Output A3 is only used when the O
2
sensor option is installed
See Figure 3-2 for the location of the analog output connector on the instrument’s rear panel.
Teledyne Analytical Instruments 125
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.4.1. Analog Output Signal Type and Range Span Selection
To select an output signal type (DC Voltage or current) and level for one output channel, activate the
ANALOG I/O CONFIGURATION MENU (See Section 6.13.1) then press:
FROM ANALOG I/O CONFIGURATION MENU
DIAG ANALOG I / O CONFIGURATION
PREV NEXT ENTR EXIT
DIAG AIO AOUTS CALIBRATED: NO
< SET
SET>
CAL EXIT Press SET> to select the analog output channel to be configured. Press EDIT to continue
DIAG AIO CONC_OUT_2:5V, CAL
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 RANGE: 5V
SET> EDIT EXIT
To set the signal level and type of the selected channel
DIAG AIO OUTPUT RANGE: 5V
0.1V 1V 5V 10V CURR ENTR EXIT
DIAG AIO OUTPUT RANGE:
10V
0.1V 1V 5V 10V CURR ENTR EXIT
Pressing ENTR records the new setting and returns to the previous menu.
Pressing EXIT ignores the new setting and returns to the previous menu.
6.13.4.2. Analog Output Calibration Mode
The analog outputs can be calibrated automatically or manually. In its default mode, the instrument is configured for automatic calibration of all channels. Manual calibration should be used for the 0.1V range or in cases where the outputs must be closely matched to the characteristics of the recording device.
Outputs configured for automatic calibration can be calibrated as a group or individually. Calibration of the analog outputs needs to be carried out on first startup of the analyzer (performed in the factory as part of the configuration process) or whenever re-calibration is required.
Teledyne Analytical Instruments 126
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To calibrate the outputs as a group, activate the ANALOG I/O CONFIGURATION MENU (See Section
6.13.1), then press:
STARTING FROM DIAGNOSTIC MENU
(see Section 6.13.1)
DIAG ANALOG I / O CONFIGURATION
Exit at any time to return to the main DIAG menu
PREV NEXT ENTR EXIT
DIAG AIO AOUTS CAL IBRATED: NO
< SET SET> CAL EXIT
If AutoCal has been turned off for any channel, the message for that channel will be similar to:
NOT AUTO CAL
CONC_OUT_1
If any of the channels have not been calibrated this message will read NO.
DIAG AIO AUTO CALIBRATING CONC_OUT_1
AUTO CALIBRATING CONC_OUT_2
AUTO CALIBRATING TEST_OUTPUT
DIAG AIO AOUTS CALIBRATED: YES
Exit to return to the I/O configuration menu
< SET SET> CAL EXIT
To automatically calibrate a single analog channel, activate the ANALOG I/O CONFIGURATION MENU
(See Section 6.13.1), then press:
Teledyne Analytical Instruments 127
Operating Instructions
DIAG ANALOG I / O CONFIGURATION
PREV NEXT ENTR EXIT
Model GFC7000TA Carbon Dioxide Analyzer
EXIT to Return to the main
Sample Display
DIAG AIO AOUTS CALIBRATED:
< SET> CAL
NO
EXIT
Press SET> to select the
Analog Output channel to be configured. Then Press
EDIT
to continue
DIAG AIO CONC_OUT_2:5V, CAL
< SET SET>
EDIT
EXIT
DIAG AIO
CONC_OUT_2 RANGE: 5V
SET> EDIT EXIT
DIAG AIO
CONC_OUT_2 REC OFS: 0 mV
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 AUTO CAL: ON
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 CALIBRATED: NO
<SET CAL EXIT
DIAG AIO AUTO CALIBRATING CONC_OUT_2
DIAG AIO CONC_OUT_2 CALIBRATED:
<SET CAL
YES
EXIT
Teledyne Analytical Instruments 128
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To select manual output calibration for a particular channel, activate the ANALOG I/O
CONFIGURATION MENU (See Section 6.13.1), then press:
Exit to return to the main sample display
DIAG ANALOG I / O CONFIGURATION
PREV NEXT ENTR EXIT
DIAG AIO CONC_OUT_2 REC OFS: 0 mV
< SET SET> EDIT EXIT
DIAG AIO AOUTS CALIBRATED: NO
< SET SET> CAL EXIT
DIAG AIO CONC_OUT_2 AUTO CAL: ON
< SET SET> EDIT EXIT
Press SET> to select the analog output channel to be configured. Then press EDIT to continue
DIAG AIO CONC_OUT_2:5V, CAL
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 AUTO CAL: ON
ON ENTR EXIT
DIAG AIO CONC_OUT_2 RANGE: 5V
SET> EDIT EXIT
Toggles the auto cal mode
ON/ OFF for this analog output channel only.
ENTR accepts the new setting and returns to the previous menu. EXIT ignores the new setting and returns to the previous menu.
Now the analog output channels should either be automatically calibrated or they should be set to manual calibration, which is described next.
6.13.4.3. Manual Analog Output Calibration and Voltage Adjustment
For highest accuracy, the voltages of the analog outputs can be manually calibrated. Calibration is done through the instrument software with a voltmeter connected across the output terminals (Figure 6-15).
Adjustments are made using the touchscreen buttons by setting the zero-point first and then the spanpoint (Table 6-20).
The software allows this adjustment to be made in 100, 10 or 1 count increments.
Table 6-20: Voltage Tolerances for Analog Output Calibration
Full Scale
0.1 VDC
1 VDC
5 VDC
10 VDC
Zero Tolerance
±0.0005V
±0.001V
±0.002V
±0.004V
Span Voltage
90 mV
900 mV
4500 mV
4500 mV
Span Tolerance
±0.001V
±0.001V
±0.003V
±0.006V
NOTE
Outputs configured for 0.1V full scale should always be calibrated manually
Teledyne Analytical Instruments 129
Operating Instructions
See Table 3-1 for pin assignments of Analog Out connector on the rear panel
Model GFC7000TA Carbon Dioxide Analyzer
V
+DC Gnd
V OUT +
V OUT -
V IN +
V IN -
Recording
Device
ANALYZER
Figure 6-11: Setup for Calibrating Analog Voltage Outputs
To make these adjustments, the AOUT auto-calibration feature must be turned off (Section 6.13.4.2).
Activate the ANALOG I/O CONFIGURATION MENU (See Section 6.13.1), then press:
Teledyne Analytical Instruments 130
Operating Instructions
FROM ANALOG I/O CONFIGURATION MENU
DIAG ANALOG I / O CONFIGURATION
PREV NEXT ENTR EXIT
Model GFC7000TA Carbon Dioxide Analyzer
DIAG AIO CONC_OUT_1 RANGE: 5V
SET> EDIT EXIT
DIAG AIO AOUTS CALIBRATED:
< SET SET> CAL
NO
EXIT
DIAG AIO CONC_OUT_1 REC OFS: 0 mV
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_1 AUTO CAL: OFF
< SET SET> EDIT EXIT
If AutoCal is ON, go to
Section 6.7.3
Press SET> to select the analog output channel to be configured:
=
A4
DIAG AIO CONC_OUT_1 :5V, NO CAL
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 CALIBRATED: NO
< SET CAL EXIT
DIAG AIO CONC_OUT_1 VOLT–Z : 0 mV
U100 UP10 UP DOWN DN10 D100 ENTR EXIT
Press to increase / decrease the analog output by 100, 10 or 1 counts.
Continue adjustments until the voltage measured at the output of the analyzer and/or the input of the recording device matches the value in the upper right hand corner of the display to the tolerance listed in Table 6-20.
The concentration display will not change. Only the voltage reading of your voltmeter will change.
DIAG AIO CONC_OUT_1 VOLT–S : 4500 mV
U100 UP10 UP DOWN DN10 D100 ENTR EXIT
EXIT ignores the new setting.
ENTR accepts the new setting.
DIAG AIO CONC_OUT_1 CALIBRATED: YES
< SET CAL EXIT
6.13.4.4. Current Loop Output Adjustment
A current loop option is available and can be installed as a retrofit for each of the analog outputs of the analyzer (s 5.2). This option converts the DC voltage analog output to a current signal with 0-20 mA output current. The outputs can be scaled to any set of limits within that 0-20 mA range. However, most current loop applications call for either 2-20 mA or 4-20 mA range. All current loop outputs have a +5% over-range. Ranges with the lower limit set to more than 1 mA (e.g., 2-20 or 4-20 mA) also have a -5% under-range.
To switch an analog output from voltage to current loop after installing the current output printed circuit assembly, follow the instructions in Section 6.13.4.4 and select CURR from the list of options on the
RANGE menu.
Adjusting the signal zero and span values of the current loop output is done by raising or lowering the voltage of the respective analog output. This proportionally raises or lowers the current produced by the current loop option.
Similar to the voltage calibration, the software allows this current adjustment to be made in 100, 10 or 1 count increments. Since the exact current increment per voltage count varies from output to output and from instrument to instrument, you will need to measure the change in the current with a current meter placed in series with the output circuit (Figure 6-16).
Teledyne Analytical Instruments 131
Operating Instructions
See Table 3-1 for pin assignments of the Analog Out connector on the rear panel.
Model GFC7000TA Carbon Dioxide Analyzer mA
IN OUT
V OUT +
V OUT -
I IN +
I IN -
Analyzer
Recording
Device
Figure 6-12: Setup for Calibrating Current Outputs
NOTE
Do not exceed 60 V between current loop outputs and instrument ground.
To adjust the zero and span values of the current outputs, activate the ANALOG I/O
CONFIGURATION MENU (See Section 6.13.1), then press:
Teledyne Analytical Instruments 132
Operating Instructions
FROM ANALOG I/O CONFIGURATION MENU
DIAG
PREV NEXT ENTR EXIT
DIAG AIO
SET> EDIT
AIN CALIBRATED: NO
EXIT
Model GFC7000TA Carbon Dioxide Analyzer
The instrument attempt to automatically calibrate the channel … then beep.
DIAG AIO CONC_OUT_2 D/A/ CAL ERROR
EXIT
DIAG AIO CONC_OUT_2 CURR-Z: 0 mV
U100 UP10 UP DOWN DN10 D100 ENTR EXIT
Press SET> to select the analog output channel to be configured:.
DIAG AIO CONC_OUT_2:CURR, NO CAL
< SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 ZERO: 27 mV
U100 UP10 UP DOWN DN10 D100 ENTR EXIT
Increase or decrease the current output by 100, 10 or 1 counts.
The resulting change in output voltage is displayed in the upper line.
Continue adjustments until the correct current is measured with the current meter.
DIAG AIO CONC_OUT_2 RANGE: CURR
<SET SET> EDIT EXIT
DIAG AIO CONC_OUT_2 SPAN: 10000 mV
U100 UP10 UP DOWN DN10 D100 ENTR EXIT
DIAG AIO CONC_OUT_2 CALIBRATED: NO
< SET CAL EXIT
DIAG AIO CONC_OUT_2 ZERO: 9731 mV
U100 UP10 UP DOWN DN10 D100 ENTR EXIT
EXIT ignores the new setting, ENTR accepts the new setting.
DIAG AIO AUTO CALIBRATING CONC_OUT_2
DIAG AIO CONC_OUT_2 CALIBRATED: YES
< SET CAL EXIT
If a current meter is not available, an alternative method for calibrating the current loop outputs is to connect a 250 1% resistor across the current loop output. Using a voltmeter connected across the resistor, follow the procedure above but adjust the output to the following values:
Table 6-21: Current Loop Output Calibration with Resistor
Full scale
0%
100%
Voltage for 2-20 mA
(measured across resistor)
0.5 V
5.0 V
Voltage for 4-20 mA
(measured across resistor)
1.0 V
5.0 V
Teledyne Analytical Instruments 133
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.4.5. AIN Calibration
This is the sub-menu to conduct the analog input calibration. This calibration should only be necessary after major repair such as a replacement of CPU, motherboard or power supplies. Activate the ANALOG
I/O CONFIGURATION MENU (See Section 6.13.1), then press:
STARTING FROM ANALOG I / O CONFIGURATION MENU
DIAG ANALOG I / O CONFIGURATION
PREV NEXT
ENTR
EXIT
Exit at any time to return to the main
DIAG menu
Continue pressing SET? until …
Instrument calibrates automatically
DIAG AIO
AIN CALIBRATED:
< SET SET> CAL
NO
EXIT
DIAG AIO
CALIBRATING A/D ZERO
CALIBRATING A/D SPAN
DIAG AIO AIN CALIBRATED:
YES
< SET SET> CAL
EXIT
Exit to return to the
ANALOG I/O
CONFIGURATION
MENU
6.13.4.6. Configuring Analog Inputs (Option) Channels
To configure the analyzer’s external analog inputs option, define for each channel:
gain (number of units represented by 1 volt)
offset (volts)
engineering units to be represented in volts (each press of the touchscreen button scrolls the list of alphanumeric characters from A-Z and 0-9)
whether to display the channel in the Test functions
To access and adjust settings for the external Analog Inputs option channels press:
Teledyne Analytical Instruments 134
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
DIAG ANALOG I / O CONFIGURATION
PREV NEXT ENTR EXIT
DIAG AIO AOUTS CALIBRATED: NO
< SET SET> CAL EXIT
Press SET> to scroll to the first channel. Continue pressing SET> to view each of 8 channels.
DIAG AIO XIN1:1.00,0.00,V,OFF
< SET SET> EDIT EXIT
Press EDIT at any channel to to change Gain, Offset,
Units and whether to display the channel in the Test functions (OFF/ON).
DIAG AIO XIN1 GAIN:1.00V/V
SET> EDIT EXIT
DIAG AIO XIN1 OFFSET:0.00V
< SET SET> EDIT
DIAG AIO XIN1 UNITS:V
< SET SET> EDIT
DIAG AIO XIN1 DISPLAY:OFF
< SET EDIT
EXIT
EXIT
EXIT
DIAG AIO XIN1 GAIN:1.00V/V
+ 0 0 1 .0 0 ENTR EXIT
Press to change
Gain value
Pressing ENTR records the new setting and returns to the previous menu.
Pressing EXIT ignores the new setting and returns to the previous menu.
Teledyne Analytical Instruments 135
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.5. Electric Test
The electric test function substitutes simulated signals for CO
2
MEAS and CO
2
REF , generated by circuitry on the sync/demod board, for the output of the IR photo-detector. While in this mode the user can also view the same test functions viewable from the main SAMPLE display. When the test is running, the concentration reported on the front panel display should be 40.0 ppm.
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X
SECONDARY SETUP MENU
COMM VARS
DIAG
ALRM EXIT
SETUP X.X ENTER DIAG PASS: 818
8 1 8 ENTR EXIT
DIAG
NEXT
SIGNAL I / O
ENTR EXIT
Repeat Pressing NEXT unti . . .
DIAG
ELECTRIC TEST
PREV NEXT
ENTR
EXIT
DIAG ELEC RANGE=50.000 PPM
CO2= 40.0
<TST TST> EXIT
Press <TST TST> to view Test Functions
NOTE: CO
2
MEAS and CO
2
REF will be artificially altered to enforce a CO
2
reading of 40.0 ppm.
All other Test Functions will report the correct operational value
Exit returns
to the
DIAG
Menu
Teledyne Analytical Instruments 136
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.6. Dark Calibration Test
The dark calibration test interrupts the signal path between the IR photo-detector and the remainder of the sync/demod board circuitry. This allows the instrument to compensate for any voltage levels inherent in the sync/demod circuitry that might effect the calculation of CO
2 concentration. Performing this calibration returns two offset voltages, One for CO
2
MEAS and on for CO
2
REF that are automatically added to the CPU’s calculation routine. The two offset voltages from the last calibration procedure may be reviewed by the user via the front panel display.
To activate the dark calibration procedure or review the results of a previous calibration, press:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
DIAG SIGNAL
NEXT
O
ENTR EXIT SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
Repeat Pressing NEXT until . . .
SETUP X.X ENTER DIAG PASS: 818
8 1 8 ENTR EXIT
DIAG DARK CALIBRATION
PREV NEXT ENTR EXIT
Electric offset for Reference signal
DIAG DARK REF DARK OFFSET: 0.0 mV
EXIT
DIAG DARK CO2 DARK CALIBRATION
VIEW CAL EXIT
Calibration runs automatically
DIAG DARK DARK CAL 1% COMPLETE
EXIT
Exit returns
to the previous menu
Display tracks % complete
Electric offset for Measurement signal
DIAG DARK MEAS DARK OFFSET: 0.0 mV
EXIT
DIAG DARK DARK CALIBRATION ABORTED
EXIT
Teledyne Analytical Instruments 137
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.7. Pressure Calibration
A sensor at the exit of the sample chamber continuously measures the pressure of the sample gas. This data is used to compensate the final CO
2
concentration calculation for changes in atmospheric pressure and is stored in the CPU’s memory as the test function PRES (also viewable via the front panel).
NOTE
This calibration must be performed when the pressure of the sample gas is equal to ambient atmospheric pressure.
Before performing the following pressure calibration procedure, disconnect the sample gas pump and the sample gas-line vent from the sample gas inlet on the instrument’s rear panel.
To cause the analyzer to measure and record a value for PRES, press.
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
Exit at any time to return to main the
SETUP menu
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X ENTER DIAG PASS: 818
8 1 8 ENTR EXIT
DIAG
NEXT
SIGNAL I / O
ENTR EXIT
Repeat Pressing NEXT until . .
.
DIAG PCAL ACTUAL PRESS : 27.20 IN-HG-A
2 7 .2 0 ENTR EXIT
Adjust these values until the displayed pressure equals the pressure measured by the independent pressure meter.
ENTR accepts the new value and returns to the previous menu
EXIT ignores the new value and returns to the previous menu
Teledyne Analytical Instruments 138
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.8. Flow Calibration
The flow calibration allows the user to adjust the values of the sample flow rates as they are displayed on the front panel and reported through COM ports to match the actual flow rate measured at the sample inlet. This does not change the hardware measurement of the flow sensors, only the software calculated values.
To carry out this adjustment, connect an external, sufficiently accurate flow meter to the sample inlet (see
Section 11 for more details). Once the flow meter is attached and is measuring actual gas flow, press:
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG ACAL DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG EXIT
Exit at any time to return to main the
SETUP menu
SETUP X.X ENTER DIAG PASS: 818
8 1 8 ENTR EXIT
DIAG SIGNAL I / O
NEXT
ENTR EXIT
Adjust these values until the displayed flow rate equals the flow rate being
Repeat Pressing NEXT until . .
.
measured by the independent flow meter.
DIAG FLOW CALIBRATION
PREV NEXT ENTR EXIT
Adjust these values until the displayed flow rate equals the flow rate being measured by the independent flow meter.
DIAG FCAL ACTUAL FLOW: 654 CC / M
0 6 5 4 ENTR EXIT
Exit returns
to the previous menu
ENTR accepts the new value and returns to the previous menu
EXIT ignores the new value and returns to the previous menu
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.13.9. Test Channel Output
When activated, output channel A4 can be used to report one of the test functions viewable from the
SAMPLE mode display. To activate the A4 channel and select a test function, follow this button sequence:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
SETUP X.X
PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
SETUP X.X
SECONDARY SETUP MENU
COMM VARS
DIAG
ALRM EXIT
SETUP X.X ENTER DIAG PASS: 818
8 1 8 ENTR EXIT
DIAG
NEXT
SIGNAL I / O
ENTR EXIT
DIAG
PREV
NEXT
ANALOG OUTPUT
ENTR EXIT
Continue to press NEXT until …
DIAG
TEST CHAN OUTPUT
PREV NEXT
ENTR
EXIT
DIAG TCHN
NEXT
TEST CHANNEL: NONE
ENTR EXIT
DIAG TCHN
TEST CHANNEL: CO2 MEASURE
PREV NEXT ENTR EXIT
Press PREV or NEXT to move through the list of available parameters
(Table 6-13)
Press ENTR to select the displayed parameter activating the test channel.
Press EXIT to return to the
DIAG
menu
Table 6-22: Test Parameters Available for Analog Output A4
TEST CHANNEL
NONE
CO
2
MEASURE
CO
2
REFERENCE
SAMPLE PRESS
SAMPLE FLOW
SAMPLE TEMP
BENCH TEMP
WHEEL TEMP
CHASSIS TEMP
PHT DRIVE
ZERO FULL SCALE
Test Channel is turned off
0 mV
0 mV
5000 mV*
5000 mV*
0 "Hg 40 "Hg
0 cc/m 1000 cc/m
0 C 70C
0 C 70C
0 C 70C
0 C 70C
0 mV 5000 mV
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
* This refers to the internal voltage level of the function NOT the output signal level of the Test channel itself.
6.14. SETUP
MORE ALRM: Using the Gas Concentration
Alarms
The Model GFC 7000TA includes two CO
2
concentration alarms. Each alarm has a user settable limit, and is associated with an opto-isolated TTL relay accessible via the status output connector on the instrument’s back panel (See Section 6.15.1.1). If the CO
2
concentration measured by the instrument rises above that limit, the alarm‘s status output relay is closed.
The default settings for ALM1 and ALM2 are:
Table 6-23: CO
2
Concentration Alarm Default Settings
ALARM STATUS LIMIT SET POINT
1
ALM1
ALM2
1
Set points listed are for PPM. Should the reporting range units of measure be changed (See Section 6.7.6) the analyzer will automatically scale the set points to match the new range unit setting.
Note
To prevent the concentration alarms from activating during span calibration operations make sure to press CAL or CALS button prior to introducing span gas into the analyzer.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.14.1. Setting the Concentration Alarm Limits
To enable either of the CO
2
concentration alarms and set the Limit points, press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X ALARM MENU
ALM1 ALM2 EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X. ALARM 1 LIMIT: OFF
OFF ENTR EXIT
SETUP X. ALARM 1 LIMIT: ON
ON ENTR EXIT
Toggle these buttons to scroll through the available character set:
0-9
SETUP X. ALARM 1 LIMIT: 200.00 PPM
0 1 0 0 .0 0 ENTR EXIT
ENTR accepts the new settings
EXIT ignores the new settings
6.15. Remote Operation of the Analyzer
6.15.1. Remote Operation Using the External Digital I/O
6.15.1.1. Status Outputs
The status outputs report analyzer conditions via optically isolated NPN transistors, which sink up to 50 mA of DC current. These outputs can be used interface with devices that accept logic-level digital inputs, such as programmable logic controllers (PLC’s). Each Status bit is an open collector output that can withstand up to 40 VDC. All of the emitters of these transistors are tied together and available at D.
NOTE
Most PLC’s have internal provisions for limiting the current that the input will draw from an external device. When connecting to a unit that does not have this feature, an external dropping resistor must be used to limit the current through the transistor output to less than 50 mA. At 50 mA, the transistor will drop approximately 1.2V from its collector to emitter.
The status outputs are accessed via a 12-pin connector on the analyzer’s rear panel labeled STATUS.
The function of each pin is defined in Table 6–24.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
STATUS
1 2 3 4 5 6 7 8 D +
Figure 6-13: Status Output Connector
Teledyne Analytical Instruments 143
8
D
+
3
4
5
6
7
Operating Instructions
The pin assignments for the Status Outputs are:
Model GFC7000TA Carbon Dioxide Analyzer
Table 6-24: Status Output Pin Assignments
OUTPUT #
1
2
Status Definition
SYSTEM OK
CONC VALID
HIGH RANGE
Condition
On if no faults are present.
On if CO
2
concentration measurement is valid.
If the CO
2
concentration measurement is invalid, this bit is OFF.
On if unit is in high range of DUAL or AUTO range modes.
ZERO CAL
SPAN CAL
DIAG MODE
ALARM1
On whenever the instruments zero point is being calibrated.
On whenever the instruments span point is being calibrated.
On whenever the instrument is in diagnostic mode.
On whenever the measured CO
2
ALM1
concentration is above the set point for
ALARM2
On whenever the measured CO
2
ALM2
concentration is above the set point for
EMITTER BUS
The emitters of the transistors on pins 1-8 are bused together.
DC POWER + 5 VDC
Digital Ground The ground level from the analyzer’s internal DC power supplies.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.1.2. Control Inputs
These inputs allow the user to remotely initiate Zero and Span calibrations. Two methods for energizing the inputs is provided below; the first using the internal +5V available on the CONTROL IN connector and the second, if an external, isolated supply is employed.
Table 6-25: Control Input Pin Assignments
INPUT STATUS
A
EXTERNAL ZERO
CAL
Zero calibration mode is activated. The mode field of the display will read ZERO CAL R.
B
EXTERNAL SPAN
CAL
Span calibration mode is activated. The mode field of the display will read SPAN CAL R.
Unused C
D
E
F
Unused
Unused
Unused
DIGITAL GROUND Provided to ground an external device (e.g., recorder).
U
+
DC power for Input pull ups
Internal +5V Supply
Input for +5 VDC required to activate inputs A - F. This voltage can be taken from an external source or from the “+” pin.
Internal source of +5V which can be used to activate inputs when connected to pin U.
There are two methods to activate control inputs. The internal +5V available from the “+” pin is the most convenient method (Figure 6-18). However, to ensure that these inputs are truly isolated, a separate, external 5 VDC power supply should be used.
CONTROL IN CONTROL IN
A B C D E F U +
Z
E
R
O
S
P
A
N
A B C D E F U +
Z
E
R
O
S
P
A
N
-
5 VDC Power
Supply
+
Local Power Connections External Power Connections
Figure 6-14: Control Inputs
Teledyne Analytical Instruments 145
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.2. Remote Operation Using the External Serial I/O
6.15.2.1. Terminal Operating Modes
The Model GFC 7000TA can be remotely configured, calibrated or queried for stored data through the serial ports. As terminals and computers use different communication schemes, the analyzer supports two communicate modes specifically designed to interface with these two types of devices.
Computer mode is used when the analyzer is connected to a computer with a dedicated interface program such as APICOM. More information regarding APICOM can be found in later in this or on the Teledyne Instruments website at http://www.teledyne-api.com/software/apicom/.
Interactive mode is used with a terminal emulation programs such as HyperTerminal or a “dumb” computer terminal. The commands that are used to operate the analyzer in this mode are listed in
Table 6-26.
6.15.2.2. Help Commands in Terminal Mode
Table 6-26: Terminal Mode Software Commands
COMMAND Function
Control-T
Switches the analyzer to terminal mode (echo, edit). If mode flags 1 & 2 are OFF, the interface can be used in interactive mode with a terminal emulation program.
Control-C
CR
(carriage return)
BS
(backspace)
Switches the analyzer to computer mode (no echo, no edit).
A carriage return is required after each command line is typed into the terminal/computer. The command will not be sent to the analyzer to be executed until this is done. On personal computers, this is achieved by pressing the ENTER button.
Erases one character to the left of the cursor location.
ESC
(escape)
Erases the entire command line.
? [ID] CR
Control-C
Control-P
This command prints a complete list of available commands along with the definitions of their functionality to the display device of the terminal or computer being used. The ID number of the analyzer is only necessary if multiple analyzers are on the same communications line, such as the multi-drop setup.
Pauses the listing of commands.
Restarts the listing of commands.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.2.3. Command Syntax
Commands are not case-sensitive and all arguments within one command (i.e. ID numbers, keywords, data values, etc.) must be separated with a space character.
All Commands follow the syntax:
X [ID] COMMAND <CR>
Where
X is the command type (one letter) that defines the type of command. Allowed designators are listed in Table 6-27 and Appendix A-6.
[ID]
COMMAND is the command designator: This string is the name of the command being issued
(LIST, ABORT, NAME, EXIT, etc.). Some commands may have additional arguments that define how the command is to be executed. Press ? <CR> or refer to Appendix A-6 for a list of available command designators.
<CR> is the analyzer identification number (Section 6.11.1.). Example: the Command “?
200” followed by a carriage return would print the list of available commands for the revision of software currently installed in the instrument assigned ID Number 200. is a carriage return. All commands must be terminated by a carriage return (usually achieved by pressing the ENTER button on a computer).
Table 6-27: Command Types
T
V
W
C
D
L
Calibration
Diagnostic
Logon
Test measurement
Variable
Warning
6.15.2.4. Data Types
Data types consist of integers, hexadecimal integers, floating-point numbers, Boolean expressions and text strings.
Integer data are used to indicate integral quantities such as a number of records, a filter length, etc.
They consist of an optional plus or minus sign, followed by one or more digits. For example, +1, -12,
123 are all valid integers.
Hexadecimal integer data are used for the same purposes as integers. They consist of the two characters “0x,” followed by one or more hexadecimal digits (0-9, A-F, a-f), which is the ‘C’ programming language convention. No plus or minus sign is permitted. For example, 0x1, 0x12,
0x1234abcd are all valid hexadecimal integers.
Floating point numbers are used to specify continuously variable values such as temperature set points, time intervals, warning limits, voltages, etc. They consist of an optional plus or minus sign,
Teledyne Analytical Instruments 147
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer followed by zero or more digits, an optional decimal point, and zero or more digits. (At least one digit must appear before or after the decimal point.) Scientific notation is not permitted. For example, +1.0,
1234.5678
, -0.1, 1 are all valid floating-point numbers.
Boolean expressions are used to specify the value of variables or I/O signals that may assume only two values. They are denoted by the keywords ON and OFF.
Text strings are used to represent data that cannot be easily represented by other data types, such as data channel names, which may contain letters and numbers. They consist of a quotation mark, followed by one or more printable characters, including spaces, letters, numbers, and symbols, and a final quotation mark. For example, “a”, “1”, “123abc”, and “()[]<>” are all valid text strings. It is not possible to include a quotation mark character within a text string.
Some commands allow you to access variables, messages, and other items, such as DAS data channels, by name. When using these commands, you must type the entire name of the item; you cannot abbreviate any names.
6.15.2.5. Status Reporting
Reporting of status messages as an audit trail is one of the three principal uses for the RS-232 interface
(the other two being the command line interface for controlling the instrument and the download of data in electronic format). You can effectively disable the reporting feature by setting the interface to quiet mode
(Section 6.11.5., Table 6-10).
Status reports include DAS data (when reporting is enabled), warning messages, calibration and diagnostic status messages. Refer to Appendix A-3 for a list of the possible messages, and this for information on controlling the instrument through the RS-232 interface.
General Message Format
All messages from the instrument (including those in response to a command line request) are in the format:
X DDD:HH:MM [Id] MESSAGE<CRLF>
Where:
X is a command type designator, a single character indicating the message type, as shown in the Table 6-27.
DDD:HH:MM is the time stamp, the date and time when the message was issued. It consists of the Day-of-year (DDD) as a number from 1 to 366, the hour of the day (HH) as a number from 00 to 23, and the minute (MM) as a number from 00 to 59.
[ID] is the analyzer ID, a number with 1 to 4 digits.
MESSAGE is the message content that may contain warning messages, test measurements, DAS reports, variable values, etc.
<CRLF> is a carriage return / line feed pair, which terminates the message.
The uniform nature of the output messages makes it easy for a host computer to parse them into an easy structure. Keep in mind that the front panel display does not give any information on the time a message was issued, hence it is useful to log such messages for trouble-shooting and reference purposes.
Teledyne Analytical Instruments 148
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Terminal emulation programs such as HyperTerminal can capture these messages to text files for later review.
Teledyne Analytical Instruments 149
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.2.6. Remote Access by Modem
The GFC 7000TA can be connected to a modem for remote access. This requires a cable between the analyzer’s COM port and the modem, typically a DB-9F to DB-25M cable (available from Teledyne
Instruments with part number WR0000024).
Once the cable has been connected, check to make sure the DTE-DCE is in the correct position. Also make sure the GFC 7000TA COM port is set for a baud rate that is compatible with the modem, which needs to operate with an 8-bit word length with one stop bit.
The first step is to turn on the MODEM ENABLE communication mode (Mode 64, Section 6.11.5). Once this is completed, the appropriate setup command line for your modem can be entered into the analyzer.
The default setting for this feature is
AT Y0 &D0 &H0 &I0 S0=2 &B0 &N6 &M0 E0 Q1 &W0
This string can be altered to match your modem’s initialization and can be up to 100 characters long.
To change this setting press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
SETUP X.X COM1 MODE:0
SET>
EDIT EXIT
SETUP X.X
PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
SETUP X.X COM1 BAUD RATE:19200
<SET SET> EDIT EXIT
EXIT
returns to the previous menu
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X COM1 MODEM INIT:AT Y &D &H
<SET SET>
EDIT
EXIT
SETUP X.X COMMUNICATIONS MENU
ID INET
COM1
COM2 EXIT
SETUP X.X COM1 MODEM INIT: [A] T Y &D &H
<CH CH> INS DEL [A]
EXIT
ENTR accepts the new string and returns to the previous menu.
EXIT ignores the new string and returns to the previous menu.
<CH and CH> move the [ ] cursor left and right along the text string
INS
inserts a character before the cursor location.
DEL deletes a character at the cursor location.
Press the [?] key repeatedly to cycle through the available character set:
0-9
A-Z space ’ ~ !
# $ % ^ & * ( ) - _ =
+[ ] { } < >\ | ; : , . / ?
Teledyne Analytical Instruments 150
Operating Instructions
To initialize the modem press:
Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X COM1 MODE:0
SET> EDIT EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
EXIT returns to the previous menu
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X COM1 BAUD RATE:19200
<SET SET> EDIT EXIT
SETUP X.X COMMUNICATIONS MENU
ID INET COM1 COM2 EXIT
SETUP X.X COM1 MODEM INIT:AT Y &D &H
<SET SET> EDIT EXIT
SETUP X.X COM1 INITIALIZE MODEM
<SET SET> INIT EXIT
SETUP X.X INITIALIZING MODEM
<SET SET> INIT EXIT
EXIT returns to the
Communications Menu.
6.15.2.7. COM Port Password Security
In order to provide security for remote access of the GFC 7000TA, a LOGON feature can be enabled to require a password before the instrument will accept commands. This is done by turning on the
SECURITY MODE (Mode 4, Section 6.11.5). Once the SECURITY MODE is enabled, the following items apply.
A password is required before the port will respond or pass on commands.
If the port is inactive for one hour, it will automatically logoff, which can also be achieved with the
LOGOFF command.
Three unsuccessful attempts to log on with an incorrect password will cause subsequent logins to be disabled for 1 hour, even if the correct password is used.
If not logged on, the only active command is the '?' request for the help screen.
The following messages will be returned at logon:
LOGON SUCCESSFUL - Correct password given
LOGON FAILED - Password not given or incorrect
LOGOFF SUCCESSFUL - Connection terminated successfully
To log on to the Model GFC 7000TA analyzer with SECURITY MODE feature enabled, type:
LOGON 940331
940331 is the default password. To change the default password, use the variable RS232_PASS issued as follows:
V RS232_PASS=NNNNNN
Teledyne Analytical Instruments 151
Operating Instructions
Where N is any numeral between 0 and 9.
Model GFC7000TA Carbon Dioxide Analyzer
6.15.2.8. APICOM Remote Control Program
APICOM is an easy-to-use, yet powerful interface program that allows accessing and controlling any of
Teledyne Instruments’ main line of ambient and stack-gas instruments from a remote connection through direct cable, modem or Ethernet. Running APICOM, a user can:
Establish a link from a remote location to the GFC 7000TA through direct cable connection via RS-232 modem or Ethernet.
View the instrument’s front panel and remotely access all functions that could be accessed when standing in front of the instrument.
Remotely edit system parameters and set points.
Download, view, graph and save data for predictive diagnostics or data analysis.
Retrieve, view, edit, save and upload DAS configurations.
Check on system parameters for trouble-shooting and quality control.
APICOM is very helpful for initial setup, data analysis, maintenance and trouble-shooting. Figure 6-5 shows an example of APICOM being used to remotely configuration the instruments DAS feature. Figure
6-19 shows examples of APICOM’s main interface, which emulates the look and functionality of the instruments actual front panel
Figure 6-15: APICOM Remote Control Program Interface
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
APICOM is included free of cost with the analyzer and the latest versions can also be downloaded for free at http://www.teledyne-api.com/software/apicom/.
6.15.3. Additional Communications Documentation
Table 6-28: Serial Interface Documents
INTERFACE / TOOL DOCUMENT TITLE PART
NUMBER
APICOM
DAS Manual
Detailed description of the DAS. 028370000
* These documents can be downloaded at http://www.teledyne-api.com/manuals/
AVAILABLE ONLINE*
YES
6.15.4. Using the GFC 7000TA with a Hessen Protocol Network
6.15.4.1. General Overview of Hessen Protocol
The Hessen protocol is a multidrop protocol, in which several remote instruments are connected via a common communications channel to a host computer. The remote instruments are regarded as slaves of the host computer. The remote instruments are unaware that they are connected to a multidrop bus and never initiate Hessen protocol messages. They only respond to commands from the host computer and only when they receive a command containing their own unique ID number.
The Hessen protocol is designed to accomplish two things: to obtain the status of remote instruments, including the concentrations of all the gases measured; and to place remote instruments into zero or span calibration or measure mode. TAI’s implementation supports both of these principal features.
The Hessen protocol is not well defined, therefore while TAI’s application is completely compatible with the protocol itself, it may be different from implementations by other companies.
The following subs describe the basics for setting up your instrument to operate over a Hessen Protocol network. For more detailed information as well as a list of host computer commands and examples of command and response message syntax, download the Manual Addendum for Hessen Protocol from the
Teledyne Instruments web site: http://www.teledyne-api.com/manuals/index.asp .
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.4.2. Hessen com Port Configuration
Hessen protocol requires the communication parameters of the GFC 7000TA’s com ports to be set differently than the standard configuration as shown in the table below.
Table 6-29: RS-232 Communication Parameters for Hessen Protocol
Parameter Standard Hessen
Data Bits
Stop Bits
8
1
7
2
To change the rest of the com port parameters. See Section 6.11.5.
To change the baud rate of the GFC 7000TA’s com ports, See Section 6.11.8.
NOTE
Make sure that the communication parameters of the host computer are also properly set.
Also, the instrument software has a 200 ms. Latency before it responds to commands issued by the host computer. This latency should present no problems, but you should be aware of it and not issue commands to the instrument too frequently.
Teledyne Analytical Instruments 154
Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.4.3. Activating Hessen Protocol
The first step in configuring the GFC 7000TA to operate over a Hessen protocol network is to activate the
Hessen mode for com ports and configure the communication parameters for the port(s) appropriately.
Press:
Repeat the entire process to set up the COM2 port
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X
COM1 QUIET MODE: OFF
NEXT OFF ENTR EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK
MORE
EXIT
Continue pressing next until …
SETUP X.X
SECONDARY SETUP MENU
COMM
VARS DIAG ALRM EXIT
SETUP X.X
COM1 HESSEN PROTOCOL : OFF
PREV NEXT
OFF
ENTR EXIT
Select which COMM port to configure
SETUP X.X
COMMUNICATIONS MENU
ID INET COM1 COM2 EXIT
SETUP X.X
COM1 HESSEN PROTOCOL : ON
PREV NEXT ON ENTR EXIT
Toggle OFF/ON to change activate/deactivate selected mode.
The sum of the mode
IDs of the selected modes is displayed here
SETUP X.X COM1 MODE:0
SET> EDIT EXIT
SETUP X.X
COM1 E,7,1 MODE: OFF
PREV NEXT OFF ENTR EXIT
SETUP X.X COM1 E,7,1 MODE: ON
PREV NEXT ON ENTR EXIT
ENTR accepts the new settings
EXIT
ignores the new settings
6.15.4.4. Selecting a Hessen Protocol Type
Currently there are two versions of Hessen Protocol in use. The original implementation, referred to as
TYPE 1 , and a more recently released version, TYPE 2 that has more flexibility when operating with instruments that can measure more than one type of gas. For more specific information about the difference between TYPE 1and TYPE 2 download the Manual Addendum for Hessen Protocol from the
Teledyne Instruments web site: http://www.teledyne-api.com/manuals/index.asp .
To select a Hessen Protocol Type press:
Teledyne Analytical Instruments 155
Operating Instructions
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
Model GFC7000TA Carbon Dioxide Analyzer
SETUP X.X
COMMUNICATIONS MENU
ID INET HESN COM1 COM2 EXIT
SETUP X. HESSEN VARIATION: TYPE 1
SET> EDIT EXIT
SETUP X.X HESSEN VARIATION: TYPE 1
TYE1 TYPE 2 ENTR EXIT
ENTR accepts the new settings
EXIT ignores the new settings
Press to change protocol type.
SETUP X.X HESSEN VARIATION: TYPE 2
PREV NEXT OFF ENTR EXIT
NOTE
While Hessen Protocol Mode can be activated independently for COM1 and COM2,
The TYPE selection affects both Ports.
6.15.4.5. Setting The Hessen Protocol Response Mode
The Teledyne Instruments implementation of Hessen Protocol allows the user to choose one of several different modes of response for the analyzer.
Table 6-30: Teledyne Instruments Hessen Protocol Response Modes
MODE ID
CMD
BCC
TEXT
MODE DESCRIPTION
This is the Default Setting. Reponses from the instrument are encoded as the traditional command format. Style and format of responses depend on exact coding of the initiating command.
Responses from the instrument are always delimited with <STX> (at the beginning of the response,
<ETX> (at the end of the response followed by a 2 digit Block Check Code (checksum), regardless of the command encoding.
Responses from the instrument are always delimited with <CR> at the beginning and the end of the string, regardless of the command encoding.
Teledyne Analytical Instruments 156
Operating Instructions
To Select a Hessen response mode, press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
Model GFC7000TA Carbon Dioxide Analyzer
SETUP X.X COMMUNICATIONS MENU
ID INET HESN COM1 COM2 EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X HESSEN VARIATION: TYPE 1
SET> EDIT EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X HESSEN RESPONSE MODE :CMD
<SET SET> EDIT EXIT
ENTR accepts the new settings
EXIT ignores the new settings
Press to change response mode.
SETUP X.X HESSEN RESPONSE MODE :CMD
BCC TEXT EDIT ENTR EXIT
6.15.4.6. Hessen Protocol Gas ID
The Model GFC 7000TA Analyzer is a single gas instrument that measures CO
2
ID has already been set to 310. There is no need to change this setting.
. As such it’s default gas
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
6.15.4.7. Setting Hessen Protocol Status Flags
Teledyne Instruments’ implementation of Hessen protocols includes a set of status bits that the instrument includes in responses to inform the host computer of its condition. Each bit can be assigned to one operational and warning message flag. The default settings for these bit/flags are:
Table 6-31: Default Hessen Status Bit Assignments
STATUS FLAG NAME DEFAULT BIT
ASSIGNMENT
WARNING FLAGS
SAMPLE FLOW WARNING
BENCH TEMP WARNING
SOURCE WARNING
BOX TEMP WARNING
WHEEL TEMP WARNING
SAMPLE TEMP WARNING
SAMPLE PRESSURE WARNING
INVALID CONC
(The Instrument’s Front Panel Display Will Show The
Concentration As “XXXX”)
Relay Board Warning
Analog Cal Warning
Cannot Dyn Zero
Cannot Dyn Span
Invalid Conc
0001
0002
0004
0008
0010
0020
0040
0080
OPERATIONAL FLAGS
Instrument Off
In Manual Calibration Mode
In Zero Calibration Mode
In Span Calibration Mode
0100
0200
0400
0800
UNITS OF MEASURE FLAGS
UGM 0000
MGM 2000
PPB 4000
PPM 6000
SPARE/UNUSED BITS 100, 1000, 8000
UNASSIGNED FLAGS (0000)
Sync Warning
Conc Alarm 1
Conc Alarm 2
Photo Temp Warning
System Reset
Rear Board Not Detected
NOTES:
It is possible to assign more than one flag to the same Hessen status bit. This allows the grouping of similar flags, such as all temperature warnings, under the same status bit.
Be careful not to assign conflicting flags to the same bit as each status bit will be triggered if any of the assigned flags is active.
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Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
To assign or reset the status flag bit assignments, press:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL
SETUP
SETUP X.X
PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X
SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
SETUP X.X
COMMUNICATIONS MENU
ID INET HESN COM1 COM2 EXIT
Repeat pressing SET> until …
SETUP X.
HESSEN STATUS FLAGS
<SET SET> EDIT EXIT
SETUP X.
SYNC WARNING: 0000
PREV NEXT EDIT PRNT EXIT
Repeat pressing NEXT or PREV until the desired message flag is displayed. See Table 6-27.
For xxample …
SETUP X. SYSTEM RESET: 0000
PREV NEXT EDIT
PRNT
EXIT
<CH and CH> move the [ ] cursor left and right along the bit string.
SETUP X.
<CH CH>
SYSTEM RESET: [0]000
[0] ENTR EXIT
Press the [?] key repeatedly to cycle through the available character set: 0-9
Note: Values of A-F can also be set but are meaningless.
ENTR
accepts the new settings
EXIT ignores the new settings
6.15.4.8. Instrument ID Code
Each instrument on a Hessen Protocol network must have a unique ID code. The GFC 7000TA is programmed with a default ID code of 360. To change this code See Section 6.11.1
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7. CALIBRATION PROCEDURES
This contains a variety of information regarding the various methods for calibrating a Model GFC 7000TA
CO
2
Analyzer as well as other supporting information.
NOTE
The procedures in this assume that the calibration password feature is disabled
(the instruments default state). If it is enabled a password prompt screen (See
Section 6.9) will appear after the CAL, CALZ or CALS buttons are pushed but before the instrument enters the associated calibration mode.
7.1. Before Calibration
The calibration procedures in this assume that the Range Type, Range Span and units of measure have already been selected for the analyzer. If this has not been done, please do so before continuing (See
Section 6.8 for instructions).
All Gas lines should be PTFE (Teflon), FEP, glass, stainless steel or brass.
NOTE
If any problems occur while performing the following calibration procedures, refer to Section 11 of this manual for troubleshooting tips.
7.1.1. Zero Air and Span Gas
To perform the following calibration you must have sources for zero air and span gas available.
Zero Air is similar in chemical composition to the Earth’s atmosphere but scrubbed of all components that might affect the analyzer’s readings. Zero air should contain less than 25 ppb of CO
2
and other major interfering gases such as CO and Water Vapor. It should have a dew point of -5 C or less
Span Gas is a gas specifically mixed to match the chemical composition of the type of gas being measured at near full scale of the desired measurement range. It is recommended that the span gas used have a concentration equal to 80% of the full measurement range.
If Span Gas is sourced directly from a calibrated, pressurized tank, the gas mixture should be CO
2 with Zero Air or N
2
at the required ratio.
mixed
Zero air generators that condition ambient air by drying and removal of pollutants are available on the commercial market such as the Teledyne Instruments Model 701 Zero Air Generator. We recommend this type of device, in conjunction with bottled N
2
for generating zero air.
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.1.2. Calibration Gas Traceability
All equipment used to produce calibration gases should be verified against standards of the National
Institute for Standards and Technology (NIST). To ensure NIST traceability, we recommend acquiring cylinders of working gas that are certified to be traceable to NIST Standard Reference Materials (SRM).
These are available from a variety of commercial sources.
7.1.3. Data Recording Devices
A strip chart recorder, data acquisition system or digital data acquisition system should be used to record data from the GFC 7000TA’s serial or analog outputs. If analog readings are used, the response of the recording system should be checked against a NIST traceable voltage source or meter. Data recording device should be capable of bi-polar operation so that negative readings can be recorded. For electronic data recording, the GFC 7000TA provides an internal data acquisition system (DAS), which is described in detail in Section 6.7.
7.2. Manual Calibration without Zero/Span Valves
This is the basic method for manually calibrating the Model GFC 7000TA CO
(Section 3) of this manual and is repeated her for you convenience.
2
Analyzer without functioning zero/span valve options. It is identical to the method described in the GETTING STARTED
STEP ONE: Connect the Sources of Zero Air and Span Gas as shown below.
Figure 7-1: Pneumatic Connections–Basic Configuration–Using Bottled Span Gas
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
Figure 7-2: Pneumatic Connections–Basic Configuration–Using Gas Dilution Calibrator
STEP TWO: Set the expected CO
2
Span Gas concentration:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP This sequence causes the analyzer to prompt for the expected CO
2
span concentration.
M-P CAL RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > ZERO CONC EXIT
The CO
2
span concentration values automatically default to
400.0 Conc .
To change this value to the actual concentration of the span gas, enter the number by pressing the button under each digit until the expected value appears.
M-P CAL CO2 SPAN CONC: 400.000 Conc
0 0 0 4 5 .0
ENTR EXIT
EXIT ignores the new setting and returns to the previous display.
ENTR accepts the new setting and returns to the previous display..
NOTE
For this Initial Calibration it is important to independently verify the PRECISE CO
2
Concentration
Value of the SPAN gas.
If the source of the Span Gas is from a Calibrated Bottle, use the exact concentration value printed on the bottle.
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
STEP THREE: Perform the Zero/Span Calibration Procedure:
SAMPLE* RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > CAL SETUP
Set the Display to show the
STABIL test function.
This function calculates the stability of the CO measurement
2
SAMPLE STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL SETUP
ACTION:
Allow zero gas to enter the sample port at the rear of the instrument.
Wait until STABIL falls below 1.0 ppm.
This may take several minutes.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL SETUP
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > ZERO CONC EXIT
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > ENTR CONC EXIT
Press ENTR to changes the
OFFSET & SLOPE values for the
CO
2
measurements.
Press EXIT to leave the calibration unchanged and return to the previous menu.
ACTION:
Allow span gas to enter the sample port at the rear of the instrument.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > SPAN CONC EXIT
The value of
STABIL may jump significantly.
Wait until it falls back below 1.0 ppm
This may take several minutes. The SPAN button appears.
If either the ZERO or
SPAN buttons fail to appear see Section 11 for troubleshooting tips.
M-P CAL RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ENTR SPAN CONC EXIT
Press ENTR to change the
OFFSET & SLOPE values for the
CO
2
measurements.
Press EXIT to leave the calibration unchanged and return to the previous menu.
M-P CAL RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ENTR CONC EXIT
EXIT returns to the main
SAMPLE display
If the ZERO or SPAN buttons are not displayed, this means that the measurement made during that part of the procedure is too far out of the allowable range to do allow a reliable calibration. The reason for this must be determined before the analyzer can be calibrated. See Section 11 for troubleshooting tips.
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.3. Manual Calibration Checks
Informal calibration checks, which only evaluate but do not alter the analyzer’s response curve, are recommended as a regular maintenance item and in order to monitor the analyzer’s performance. To carry out a calibration check rather than a full calibration, follow these steps.
STEP ONE : Connect the sources of zero air and span gas as shown in Figures 7.1 or 7.2.
STEP TWO : Perform the zero/span calibration check procedure:
ACTION:
Supply the instrument with zero gas.
Scroll the display to the
STABIL test function.
SAMPLE RANGE = 500.0 PPM CO2=X.XXX
< TST TST > CAL SETUP
SAMPLE STABIL=XXX.X PPM CO2=X.XXX
< TST TST > CAL SETUP
Wait until
STABIL is below 1.0 ppm.
This may take several minutes.
SAMPLE STABIL=XXX.X PPM CO2=X.XXX
< TST TST > CAL SETUP
ACTION:
Supply span gas to the instrument
ACTION:
Record the CO
2 concentration reading.
The value of
STABIL may jump significantly.
Wait until it falls below 1.0 ppm. This may take several minutes.
ACTION:
Record the CO concentration reading.
2
SAMPLE STABIL=XXX.X PPM CO2=X.XXX
< TST TST > CAL SETUP
The SPAN key appears during the transition from zero to span. You may see both SPAN and ZERO buttons.
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.4. Manual Calibration with Zero/Span Valves
There are four different zero/span valve option configurations (See Section 5.4). They all operate identically, differing only in the method used to supply calibration gas to the Analyzer.
STEP ONE: Connect the sources of Zero Air and Span Gas as shown below.
Figures 7-3 through 7-6 show the proper pneumatic connections for GFC 7000TAs with various optional internal valve sets installed.
Figure 7-3: Pneumatic Connections – Ambient Zero/Pressurized Span Valves
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Calibration Procedures
Source of
SAMPLE GAS
Removed during calibration
Model GFC7000TA Carbon Dioxide Analyzer
VENT here if input is pressurized
Calibrated
CO
2
Gas at span gas concentration
N
2
External
Zero Air
Scrubber
VENT
SAMPLE
EXHAUST
VENT SPAN
PRESSURE SPAN
IZS
PURGE LINE
Chassis
Figure 7-4: Pneumatic Connections – Ambient Zero/Pressurized Span Valves and External
Zero Air Scrubber
Figure 7-5: Pneumatic Connections – Ambient Zero/Ambient Span Valves
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Calibration Procedures
Calibrated
CO
2
Gas at 100x span gas concentration
Source of
SAMPLE GAS
Removed during calibration
Model T700 gas
Dilution
Calibrator
Model GFC7000TA Carbon Dioxide Analyzer
VENT here if input is pressurized
External
Zero Air
Scrubber
SAMPLE
EXHAUST
VENT SPAN
PRESSURE SPAN
IZS
PURGE LINE
Chassis
N
2
Figure 7-6: Pneumatic Connections – Ambient Zero/Ambient Span Valves with External Zero
Air Scrubber
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
STEP TWO: Set the expected CO
2
Span Gas concentration:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST >
CAL
CALZ CALS SETUP This sequence causes the analyzer to prompt for the expected CO
2
span concentration.
M-P CAL RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > ZERO CONC EXIT
The CO
2
span concentration values automatically default to
400.0 Conc .
To change this value to the actual concentration of the span gas, enter the number by pressing the button under each digit until the expected value appears.
M-P CAL CO2 SPAN CONC: 450.000 Conc
0 0 0 4 5 .0
ENTR EXIT
EXIT
ignores the new setting and returns to the previous display.
ENTR accepts the new setting and returns to the previous display.
NOTE
For this Initial Calibration it is important to independently verify the PRECISE CO
2
Concentration Value of the SPAN gas.
If the source of the Span Gas is from a Calibrated Bottle, use the exact concentration value printed on the bottle.
STEP THREE: Perform the zero/span calibration. Zero and span checks using the zero/span valve option are similar to that described in Section 7.2, except that zero air and span gas is supplied to the analyzer through the zero/span valves rather than through the sample inlet port.
The zero and cal operations are initiated directly and independently with dedicated buttons (CALZ &
CALS ).
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
SAMPLE* RANGE = 500.000 PPM CO2 =XXX.X
<TST TST> CAL CALZ CALS SETUP
Set the Display to show the
STABIL test function.
This function calculates the stability of the CO measurement x
SAMPLE STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL CALZ CALS SETUP
ACTION:
Allow zero gas to enter the sample port at the rear of the instrument.
Wait until STABIL falls below1.0 ppm.
This may take several minutes.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL CALZ CALS SETUP
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > ZERO CONC EXIT
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > ENTR CONC EXIT
Press ENTR to changes the
OFFSET & SLOPE values for the
CO
2
measurements.
Press EXIT to leave the calibration unchanged and return to the previous menu.
ACTION:
Allow span gas to enter the sample port at the rear of the instrument.
The value of
STABIL may jump significantly.
Wait until it falls back below 1.0 ppm.
This may take several minutes.
The SPAN button now appears during the transition from zero to span.
If either the ZERO or
SPAN buttons fail to appear see Section 11 for troubleshooting tips.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > SPAN CONC EXIT
M-P CAL RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ENTR SPAN CONC EXIT
M-P CAL RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ENTR CONC EXIT
Press ENTR to change the
OFFSET & SLOPE values for the
CO
2
measurements.
Press EXIT to leave the calibration unchanged and return to the previous menu.
EXIT returns to the main
SAMPLE display
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.5. Manual Calibration Checks with Zero/Span Valves
Zero and span checks using the VARIOUS zero/span valve options available for the GFC 7000TA are similar to that described in Section 7.3, except that the zero and calibration operations are initiated directly and independently with dedicated buttons CALZ and CALS.
To perform a manual calibration check of an analyzer with a valve option installed, use the following method.
STEP ONE : Connect the sources of Zero Air and Span Gas as shown in Figures 7-3 through 7-6.
STEP TWO : Perform the zero/span check.
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
Scroll to the STABIL test function.
< TST TST > CAL CALZ CALS SETUP
SAMPLE STABIL=XXX.X PPM CO2 =X.XXX
< TST TST > CAL CALZ CALS SETUP
Wait until STABIL falls below 1.0 ppm.
This may take several minutes. ZERO CAL M STABIL=XXX.X PPM CO2 =X.XXX
< TST TST > ZERO CONC EXIT
ACTION:
Record the
CO
2
readings presented in the upper right corner of the display.
SAMPLE STABIL=XXX.X PPM CO2 =X.XXX
< TST TST > CAL CALZ CALS SETUP
The value of STABIL may jump significantly. Wait until STABIL falls below 1.0 ppm. This may take several minutes.
SPAN CAL M STABIL=XXX.X PPM CO2 =X.XXX
< TST TST > ZERO SPAN CONC EXIT
ACTION:
Record the
CO2 readings presented in the upper right corner of the display.
EXIT returns to the main
SAMPLE display
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.5.1. Zero/Span Calibration on Auto Range or Dual Ranges
If the analyzer is being operated in dual range mode or auto range mode, then the high and low ranges must be independently calibrated.
When the analyzer is in either dual or auto range modes the user must run a separate calibration procedure for each range. After pressing the CAL, CALZ or CALS buttons the user is prompted for the range that is to be calibrated as seen in the CALZ example below:
SAMPLE* RANGE = 500.000 PPM CO2 =XXX.X
<TST TST> CAL CALZ CALS SETUP
Set the Display to show the
STABIL test function.
This function calculates the stability of the CO measurement
2
SAMPLE STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL CALZ CALS SETUP
ACTION:
Allow zero gas to enter the sample port at the rear of the instrument.
Wait until STABIL falls below 1.0 ppm.
This may take several minutes.
M-P CAL STABIL=XXX.X PPM CO2 =XXX.X
< TST TST > CAL CALZ CALS SETUP
ANALYZER ENTERS
ZERO CAL MODE
SAMPLE
LOW HIGH
RANGE TO CAL: LOW
ENTR SETUP
SAMPLE RANGE TO CAL: HIGH
LOW HIGH ENTR SETUP
ZERO CAL M RANGE = 500.000 PPM CO2 =XXX.X
< TST TST > ZERO SPAN CONC EXIT
Continue Calibration as per
Standard Procedure
Once this selection is made, the calibration procedure continues as previously described in Section 7.2.
The other range may be calibrated by starting over from the main SAMPLE display.
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.5.2. Use of Zero/Span Valves with Remote Contact Closure
Contact closures for controlling calibration are located on the rear panel CONTROL IN connector.
Instructions for setup and use of these contacts are found in Section 6.15.1.2. When the contacts are closed for at least 5 seconds, the instrument switches into zero or span mode. The remote calibration contact closures may be activated in any order. It is recommended that contact closures remain closed for at least 10 minutes to establish a reliable reading.
The instrument will stay in the selected mode for as long as the contacts remain closed. If calibration is enabled, the GFC 7000TA will re-calibrate when the contact is opened, then go into SAMPLE mode. If calibration is disabled, the instrument will return to SAMPLE mode, leaving the calibration unchanged.
7.6. Automatic Zero/Span Cal/Check (AutoCal)
The AutoCal system allows unattended periodic operation of the ZERO/SPAN valve options by using the
GFC 7000TA’s internal time of day clock. AutoCal operates by executing SEQUENCES programmed by the user to initiate the various calibration modes of the analyzer and open and close valves appropriately.
It is possible to program and run up to 3 separate sequences (SEQ1, SEQ2 and SEQ3). Each sequence can operate in one of 3 Modes, or be disabled.
Table 7-1: AUTOCAL Modes
MODE NAME
DISABLED
ZERO
ZERO-SPAN
SPAN
ACTION
Disables the Sequence
Causes the Sequence to perform a zero calibration/check
Causes the Sequence to perform a zero and span concentration calibration/check
Causes the Sequence to perform a span concentration calibration/check
For each mode there are seven parameters that control operational details of the SEQUENCE. They are:
Table 7-2: AutoCal ATTRIBUTE Setup Parameters
ATTRIBUTE NAME
TIMER ENABLED
STARTING DATE
STARTING TIME
DELTA DAYS
DELTA TIME
DURATION
CALIBRATE
ACTION
Turns on the Sequence timer
Sequence will operate after Starting Date
Time of day sequence will run
Number of days to skip between each Seq. execution
Number of hours later each “Delta Days” Seq is to be run
Number of minutes the sequence operates
Enable to do a calibration – Disable to do a cal check only
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
The following example sets Sequence #2 to do a Zero-Span Calibration every other day starting at 1 am on September 4, 2001, lasting 15 minutes, without calibration. This will start ½ hour later each iteration.
MODE AND ATTRIBUTE VALUE COMMENT
Timer Enable
Starting Date
Starting Time
Delta Days
Delta Time
ON
Sept. 4, 2001
01:00
2
00:30
Enable the timer
Start after Sept 4, 2001
First Span starts at 1:00AM
Do Sequence #2 every other day
Do Sequence #2 ½ hr later each day
NOTE
The programmed STARTING_TIME must be a minimum of 5 minutes later than the real time clock (See Section 6.10 for setting real time clock).
NOTE
Avoid setting two or more sequences at the same time of the day. Any new sequence which is initiated whether from a timer, the COM ports, or the contact closure inputs will override any sequence which is in progress.
NOTE
If at any time an illegal entry is selected (Example: Delta Days > 367) the ENTR button will disappear from the display.
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Calibration Procedures
To program the Sequence:
SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL CALZ CALS SETUP
Model GFC7000TA Carbon Dioxide Analyzer
SETUP X.X
STARTING TIME:14:15
<SET SET> EDIT EXIT
SETUP X.X PRIMARY SETUP MENU
CFG ACAL DAS RNGE PASS CLK MORE EXIT
SETUP X.X
DELTA DAYS: 1
<SET SET>
EDIT
EXIT
SETUP X.X
SEQ 1) DISABLED
NEXT
MODE
SETUP X.X
SEQ 2) DISABLED
PREV NEXT
MODE
EXIT
EXIT
SETUP X.X
DELTA DAYS: 1
0 0 2
SETUP X.X
DELTA DAYS:2
<SET
SET>
EDIT
ENTR
EXIT
EXIT
Toggle buttons to set number of days between procedures
(1-367)
SETUP X.X
MODE: DISABLED
NEXT
ENTR EXIT SETUP X.X
DELTA TIME00:00
<SET SET>
EDIT
EXIT
SETUP X.X
MODE: ZERO
PREV
NEXT
ENTR EXIT
SETUP X.X
MODE: ZERO–SPAN
PREV NEXT
ENTR
EXIT
SETUP X.X
DELTA TIME: 00:00
0 0 :3 0 ENTR
EXIT
Toggle buttons to set delay time for each iteration of the sequence:
HH:MM
(0 – 24:00)
SETUP X.X
DELTA TIEM:00:30
<SET
SET>
EDIT EXIT
SETUP X.X
SEQ 2) ZERO–SPAN, 1:00:00
PREV NEXT MODE
SET
EXIT
SETUP X.X
DURATION:15.0 MINUTES
<SET SET>
EDIT
EXIT
Default value is
ON
Toggle buttons to set day, month & year:
Format :
DD-MON-Y Y
SETUP X.X
TIMER ENABLE: ON
SET>
EDIT EXIT
SETUP X.X
STARTING DATE: 01–JAN–02
<SET SET>
EDIT
EXIT
SETUP X.X
STARTING DATE: 01–JAN–02
0
4 SEP
0
3 ENTR
EXIT
SETUP X.X
STARTING DATE: 04–SEP–03
<SET SET> EDIT EXIT
SETUP X.X
DURATION 15.0MINUTES
3 0 .0
ENTR
EXIT
SETUP X.X
DURATION:30.0 MINUTES
<SET SET> EDIT EXIT
SETUP X.X
CALIBRATE: OFF
<SET SET> EDIT EXIT
Toggle buttons to set duration for each iteration of the sequence:
Set in
Decimal minutes from
0.1 – 60.0
SETUP X.X
STARTING DATE: 04–SEP–03
<SET
SET>
EDIT EXIT
SETUP X.X C ALIBRATE: OFF
ON ENTR
EXIT
Toggle button between
Off and
ON
Toggle buttons to set time:
Format : HH:MM
This is a 24 hr clock .
PM hours are
13 – 24.
Example
2:15 PM = 14:15
SETUP X.X
STARTING TIME:00:00
<SET SET> EDIT EXIT
SETUP X.X
STARTING TIME:00:00
1 4 : 1 5 ENTR EXIT/
SETUP X.X
CALIBRATE: ON
<SET SET> EDIT
EXIT
SETUP X.X
SEQ 2) ZERO–SPAN, 2:00:30
PREV NEXT MODE SET
EXIT
Sequence Delta Time
MODE Delta Days
EXIT returns to the SETUP
Menu
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
7.6.1. AutoCal with Auto or Dual Reporting Ranges Modes Selected
SETUP C.4
RANGE TO CAL: LOW
<SET EDIT EXIT
SETUP C.4
RANGE TO CAL: LOW
LOW HIGH ENTR SETUP
SETUP C.4
RANGE TO CAL: HIGH
<SET EDIT EXIT
SETUP C.4
SEQ 2) ZERO–SPAN, 2:00:30
PREV NEXT MODE SET EXIT
EXIT returns to the
PRIMARY SETUP
Menu
NOTE
In order to automatically calibrate both the HIGH and LOW ranges, you must set up a separate sequence for each.
7.7. Calibration Quality
After completing one of the calibration procedures described above, it is important to evaluate the analyzer’s calibration SLOPE and OFFSET parameters. These values describe the linear response curve of the analyzer. The values for these terms, both individually and relative to each other, indicate the quality of the calibration. To perform this quality evaluation, you will need to record the values of both test functions (Section 6.2.1 or Appendix A-3), all of which are automatically stored in the DAS channel
CALDAT for data analysis, documentation and archival.
Make sure that these parameters are within the limits listed in Table 7-3 and frequently compare them to those values on the Final Test and Checkout Sheet that came attached to your manual, which should not be significantly different. If they are, refer to the troubleshooting Section 11.
Table 7-3: Calibration Data Quality Evaluation
FUNCTION MINIMUM VALUE OPTIMUM VALUE MAXIMUM VALUE
SLOPE
OFFS
0.700 1.000 1.300
-0.500 0.000 0.500
These values should not be significantly different from the values recorded on the Teledyne Instruments
Final Test and Validation Data sheet that was shipped with your instrument. If they are, refer to the troubleshooting Section 11.
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Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer
The default DAS configuration records all calibration values in channel CALDAT as well as all calibration check (zero and span) values in its internal memory. Up to 200 data points are stored for up 4 years of data (on weekly calibration checks) and a lifetime history of monthly calibrations. Review these data to see if the zero and span responses change over time. These channels also store the STABIL value
(standard deviation of CO concentration) to evaluate if the analyzer response has properly leveled off during the calibration procedure. Finally, the CALDAT channel also stores the converter efficiency for review and documentation.
If your instrument has an O
2
sensor option installed that should be calibrated as well.
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8. MAINTENANCE SCHEDULE & PROCEDURES
Predictive diagnostic functions, including data acquisition records, failure warnings and test functions built into the analyzer, allow the user to determine when repairs are necessary without performing painstaking preventative maintenance procedures. There are, however, a minimal number of simple procedures that when performed regularly will ensure that the analyzer continues to operate accurately and reliably over its lifetime. Repairs and troubleshooting are covered in Section 11 of this manual.
8.1. Maintenance Schedule
Table 9-1 shows a typical maintenance schedule for the analyzer. Please note that in certain environments (i.e. dusty, very high ambient pollutant levels) some maintenance procedures may need to be performed more often than shown.
NOTE
A Span and Zero Calibration Check (see CAL CHECK REQ’D Column of Table 9-1) must be performed following certain of the maintenance procedure listed below.
See Sections 7.3, 7.5 and 7.6 for instructions on performing checks.
CAUTION
Risk of electrical shock. Disconnect power before performing any of the following operations that require entry into the interior of the analyzer.
NOTE
The operations outlined in this section are to be performed by qualified maintenance personnel only.
Maintenance Model GFC7000TA Carbon Dioxide Analyzer
Table 8-1: GFC 7000TA Maintenance Schedule
CAL
ITEM ACTION FREQ CHECK
REQ’D.
MANUAL
Particulate
Filter
Replace
Weekly or as needed
Yes
Verify Test
Functions
Record and analyze
Weekly or after any
Maintenance or Repair
Pump
Diaphragm
No
Replace Annually Yes
Perform
Flow Check
Check Flow Annually
Perform
Leak Check
Verify Leak
Tight
Annually or after any
Maintenance or Repair
No
No
Pneumatic lines
Examine and clean
As needed
Yes if cleaned
Only if cover remv’d
DATE PERFORMED
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Table 8-2: GFC 7000TA Test Function Record
DATE RECORDED
FUNCTION
OPERATING
MODE*
STABILITY
ZERO CAL
ZERO CAL
CO2 MEAS
Zero CAL
MR RATIO
SPAN CAL
SAMPLE
PRES
PHT DRIVE
SAMPLE After
Warm-up
SPAN CAL
SLOPE
ZERO CAL
OFFSET
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8.2. Predicting Failures Using the Test Functions
The Test Functions can be used to predict failures by looking at how their values change over time.
Initially it may be useful to compare the state of these Test Functions to the values recorded on the printed record of the final calibration performed on your instrument at the factory, p/n 04307. Table 9-3 can be used as a basis for taking action as these values change with time. The internal data acquisition system (DAS) is a convenient way to record and track these changes. Use APICOM to download and review this data from a remote location.
Table 8-3: Predictive uses for Test Functions
FUNCTION CONDITION BEHAVIOR
STABILITY
CO2 MEAS
MR RATIO
PRES
PHT DRIVE
OFFSET
SLOPE
Zero Cal
Zero Cal
Zero Cal
Span Cal
Sample
Any, but with
Bench Temp at
48°C
Zero Cal
Span Cal
Increasing
Decreasing
Increasing
Decreasing
Increasing
Decreasing
Increasing > 1”
Decreasing > 1”
Increasing
Increasing
Decreasing
Increasing
Decreasing
INTERPRETATION
Pneumatic Leaks – instrument & sample system
Detector deteriorating
Source Aging
Detector deteriorating
Optics getting dirty or contaminated
Source Aging
Detector deteriorating
Contaminated zero gas (H2O)
Source Aging
Detector deteriorating
GFC Wheel Leaking
Pneumatic Leaks
Contaminated zero gas (CO
2
)
Source Aging
Pneumatic Leaks – instrument & sample system
Calibration system deteriorating
Source Aging
GFC Wheel Leaking
Calibration system deteriorating
Pneumatic Leak between sample inlet and Sample Cell
Change in sampling manifold
Dirty particulate filter
Pneumatic obstruction between sample inlet and Sample
Cell
Obstruction in sampling manifold
Mechanical Connection between IR-Detector and Sample
Cell deteriorating
IR-Photodetector deteriorating
See MR Ratio - Zero Cal Decreasing above
See MR Ratio - Zero Cal Increasing above
See MR Ratio - Span Cal Decreasing above
See MR Ratio – Span Cal Increasing above
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Maintenance Model GFC7000TA Carbon Dioxide Analyzer
8.3. Maintenance Procedures
The following procedures are to be performed periodically as part of the standard maintenance of the
Model GFC 7000TA.
8.3.1. Replacing the Sample Particulate Filter
The particulate filter should be inspected often for signs of plugging or contamination. We recommend that when you change the filter, handle it and the wetted surfaces of the filter housing as little as possible.
Do not touch any part of the housing, filter element, PTFE retaining ring, glass cover and the o-ring.
To change the filter:
1. Turn OFF the analyzer to prevent drawing debris into the instrument.
2. Open the GFC 7000TA’s hinged front panel and unscrew the knurled retaining ring on the filter assembly.
Figure 8-1: Sample Particulate Filter Assembly
3. Carefully remove the retaining ring, PTFE o-ring, glass filter cover and filter element.
4. Replace the filter, being careful that the element is fully seated and centered in the bottom of the holder.
5. Re-install the PTFE o-ring with the notches up, install the glass cover, then screw on the retaining ring and hand tighten. Inspect the seal between the edge of filter and the o-ring to assure a proper seal.
6. Re-start the Analyzer.
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8.3.2. Rebuilding the Sample Pump
The diaphragm in the sample pump periodically wears out and must be replaced. A sample rebuild kit is available – see Appendix B of this manual for the part number of the pump rebuild kit. Instructions and diagrams are included with the kit.
Always perform a Flow and Leak Check after rebuilding the Sample Pump.
8.3.3. Performing Leak Checks
Leaks are the most common cause of analyzer malfunction; Section 8.3.3.1 presents a simple leak check procedure. Section 8.3.3.2 details a more thorough procedure.
8.3.3.1. Vacuum Leak Check and Pump Check
This method is easy and fast. It detects, but does not locate most leaks; it also verifies that the sample pump is in good condition.
1. Turn the analyzer ON, and allow enough time for flows to stabilize.
2. Cap the sample inlet port.
3. After several minutes, when the pressures have stabilized, note the following. In the TEST menu, note the SAMPLE PRESSURE reading.
4. If the reading is < 10 in-Hg, the pump is in good condition and there are no large leaks.
5. Check the sample gas flow. If the flow is <10 cm 3 /min and stable, there are no large leaks in the instrument’s pneumatics.
8.3.3.2. Pressure Leak Check
If you can’t locate the leak by the above procedure, use the following procedure. Obtain a leak checker similar to the Teledyne Instruments part number 01960, which contains a small pump, shut-off valve, and pressure gauge. Alternatively, a convenient source of low-pressure gas is a tank of span gas, with the two-stage regulator adjusted to less than 15 psi with a shutoff valve and pressure gauge.
CAUTION
Do not use bubble solution with vacuum applied to the analyzer. The solution may contaminate the instrument. Do not exceed 15 PSIG pressure.
1. Turn OFF power to the instrument.
2. Install a leak checker or tank of gas as described above on the sample inlet at the rear panel.
3. Remove the instrument cover and locate the inlet side of the sample pump. Remove the flow assembly from the pump and plug it with the appropriate gas-tight fitting.
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Maintenance Model GFC7000TA Carbon Dioxide Analyzer
4. Pressurize the instrument with the leak checker, allowing enough time to fully pressurize the instrument through the critical flow orifice. Check each fitting with soap bubble solution, looking for bubbles. Once the fittings have been wetted with soap solution, do not re-apply vacuum, as it will suck soap solution into the instrument and contaminate it. Do not exceed 15 psi pressure.
5. If the instrument has one of the zero and span valve options, the normally closed ports on each valve should also be separately checked. Connect the leak checker to the normally closed ports and check with soap bubble solution.
6. Once the leak has been located and repaired, the leak-down rate should be < 1 in-Hg (0.4 psi) in
5 minutes after the pressure is shut off.
8.3.4. Performing a Sample Flow Check
CAUTION
Always use a separate calibrated flow meter capable of measuring flows in the 0 – 1000 cc/min range to measure the gas flow rate though the analyzer.
DO NOT use the built in flow measurement viewable from the Front Panel of the instrument. This measurement is only for detecting major flow interruptions such as clogged or plugged gas lines.
See Figure 3-4 for SAMPLE port location.
1. Attach the Flow Meter to the sample inlet port on the rear panel. Ensure that the inlet to the Flow
Meter is at atmospheric f.
2. Sample flow should be 800 cc/min 10%.
3. Once an accurate measurement has been recorded by the method described above, adjust the analyzer’s internal flow sensors (See Section 6.13.8)
Low flows indicate blockage somewhere in the pneumatic pathway, typically a plugged sintered filter or critical flow orifice in one of the analyzer’s flow control assemblies. High flows indicate leaks downstream of the Flow Control Assembly.
8.3.5. Cleaning the Optical Bench
The GFC 7000TA sensor assembly and optical bench is complex and delicate. Disassembly and cleaning is not recommended. Please check with the factory before disassembling the optical bench.
8.3.6. Cleaning Exterior Surfaces of the GFC 7000TA
If necessary, the exterior surfaces of the GFC 7000TA can be cleaned with a clean damp cloth. Do not submerge any part of the instrument in water or cleaning solution.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9. THEORY OF OPERATION
The Model GFC 7000TA Gas Filter Correlation Carbon Dioxide Analyzer is a microprocessor-controlled analyzer that determines the concentration of carbon dioxide (CO
2
) in a sample gas drawn through the instrument. It requires that sample and calibration gasses be supplied at ambient atmospheric pressure in order to establish a stable gas flow through the sample chamber where the gases ability to absorb infrared radiation is measured.
Calibration of the instrument is performed in software and does not require physical adjustments to the instrument. During calibration the microprocessor measures the current state of the IR Sensor output and various other physical parameters of the instrument and stores them in memory.
The microprocessor uses these calibration values, the IR absorption measurements made on the sample gas along with data regarding the current temperature and pressure of the gas to calculate a final co
2 concentration.
This concentration value and the original information from which it was calculated are stored in one of the unit’s internal data acquisition system (DAS - See Sections 6.7) as well as reported to the user via a vacuum florescent display or a variety of digital and analog signal outputs.
9.1. Measurement Method
9.1.1. Beer’s Law
The basic principle by which the analyzer works is called Beer’s Law. It defines the how light of a specific wavelength is absorbed by a particular gas molecule over a certain distance. The mathematical relationship between these three parameters is:
I = I o
e
αLc
Where:
I
o
is the intensity of the light if there was no absorption.
I
is the intensity with absorption.
L
is the absorption path, or the distance the light travels as it is being absorbed.
C
is the concentration of the absorbing gas. In the case of the Model GFC 7000TA, carbon dioxide (CO
2
).
α
is the absorption coefficient that tells how well CO
2 of interest.
absorbs light at the specific wavelength
9.1.2. Measurement Fundamentals
In the most basic terms, the Model GFC 7000TA uses a high energy heated element to generate a beam of broad-band IR light with a known intensity (measured during Instrument calibration. This beam is
Teledyne Analytical Instruments 187
Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer directed through multi-pass cell filled with sample gas. The sample cell uses mirrors at each end to reflect the IR beam back and forth through the sample gas to generate a 2.5 meter absorption path (see
Figure 10–1). This length was chosen to give the analyzer maximum sensitivity to fluctuations in CO
2 density.
Sample Chamber
Band-Pass Filter
IR
Source Photo-Detector
IR Beam
Figure 9-1: Measurement Fundamentals
Upon exiting the sample cell, the beam shines through a band-pass filter that allows only light at a wavelength of 4.3 µm to pass. Finally, the beam strikes a solid-state photo-detector that converts the light signal into a modulated voltage signal representing the attenuated intensity of the beam.
9.1.3. Gas Filter Correlation
Unfortunately, water vapor absorbs light at 4.3 µm too. To overcome the interfering effects of water vapor the Model GFC 7000TA adds another component to the IR light path called a gas filter correlation (GFC) wheel (see Figure 10-2).
Measurement Cell
(Pure N
2
)
Reference Cell
(N
2
with CO
2
)
Figure 9-2: GFC Wheel
9.1.3.1. The GFC Wheel
A GFC wheel is a metallic wheel into which two chambers are carved. The chambers are sealed on both sides with material transparent to 4.3 µm IR radiation creating two airtight cavities. Each cavity is filled with specially composed gases. One cell is filled with pure N combination of N
2
and a high concentration of CO
2
(the measure cell)
.
The other is filled with a
2
(the reference cell).
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Theory of Operation
IR unaffected by N
2
in Measurement Cell
Model GFC7000TA Carbon Dioxide Analyzer
Δ H
IR IS affected by CO
2
in Reference Cell
IR
Source
M
R
Photo-Detector
GFC Wheel
Figure 9-3: Measurement Fundamentals with GFC Wheel
As the GFC wheel spins, the IR light alternately passes through the two cavities. When the beam is exposed to the reference cell, the CO
2
in the gas filter wheel strips the beam of most of the IR at 4.3μm.
When the light beam is exposed to the measurement cell, the N
2
in the filter wheel does not absorb IR light. This results in a fluctuation in the intensity of the IR light striking the photo-detector (See Figure 10-
3) that results in the output of the detector resembling a square wave.
9.1.3.2. The Measure Reference Ratio
The Model GFC 7000TA determines the amount of CO
REF ).
2
in the sample chamber by computing the ratio between the peak of the measurement pulse (CO2 MEAS) and the peak of the reference pulse (CO2
If no gases exist in the sample chamber that absorb light at 4.3μm, the high concentration of CO approximately 2.4:1.
2
in the gas mixture of the reference cell will attenuate the intensity of the IR beam by 60% giving a M/R ratio of
Adding CO
2
to the sample chamber causes the peaks corresponding to both cells to be attenuated by a further percentage. Since the intensity of the light passing through the measurement cell is greater, the effect of this additional attenuation is greater. This causes CO2 MEAS to be more sensitive to the presence of CO
2
in the sample chamber than CO2 REF and the ratio between them (M/R) to move closer to 1:1 as the concentration of CO
2
in the sample chamber increases.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
IR unaffected by N
2
in Measurement Cell of the GFC Wheel and no additional CO the Sample Chamber
2
in
CO2 MEAS
CO2 REF
IR affected by CO
2
in Reference Cell with no interfering gas in the Sample
Chamber
IR shinning through Measurement Cell of the GFC Wheel is reduced by additional
CO
2
in the Sample Chamber
M/R is reduced
IR shining through Reference Cell is also reduced by additional CO
2
in the
Sample Chamber, but to a lesser extent
Figure 9-4: Affect of CO2 in the Sample on CO2 MEAS & CO2 REF
Once the Model GFC 7000TA has computed this ratio, a look-up table is used, with interpolation, to linearize the response of the instrument. This linearized concentration value is combined with calibration
SLOPE and OFFSET values to produce the CO
2 sample pressure.
concentration which is then normalized for changes in
9.1.4. Interference and Signal to Noise Rejection
If an interfering gas, such as H
2
O vapor is introduced into the sample chamber, the spectrum of the IR beam is changed in a way that is identical for both the reference and the measurement cells, but without changing the ratio between the peak heights of CO2 MEAS and CO2 REF. In effect, the difference between the peak heights remains the same.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
M/R is Shifted
IR shining through both cells is effected equally by interfering gas in the Sample
Chamber
Figure 9-5: Effects of Interfering Gas on CO2 MEAS & CO2 REF
Thus, the difference in the peak heights and the resulting M/R ratio is only due to CO analyzer responds only to the presence of CO
2
.
2
and not to interfering gases. In this way, Gas filter correlation rejects the effects of interfering gases and so that the
To improve the signal-to-noise performance of the IR photo-detector, the GFC wheel also incorporates an optical mask that chops the IR beam into alternating pulses of light and dark at six times the frequency of the measure/reference signal. This limits the detection bandwidth helping to reject interfering signals from outside this bandwidth improving the signal to noise ratio.
The IR Signal as the Photo-Detector sees it after being chopped by the GFC Wheel
Screen
Figure 9-6: Chopped IR Signal
CO
2
REF
CO
2
MEAS
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.1.4.1. Ambient CO
2
Interference Rejection
CO
2
absorbs IR light very well. So well that even the narrow volume of ambient air between the IR source and the sample chamber is enough to alter the analyzer’s measured concentration of CO
2
. Also, ambient air, which averages around 350 ppm to 400 ppm, will vary significantly over the course of the day. The ambient CO
2
concentration can rise as high as 1 000 ppm during the time of the day when people are present. It can fluctuate 300 ppm as the photosynthesis of plant life in the nearby area increases during the day and decreases at night.
The basic design of the GFC 7000TA rejects most of this interference at a 100:1 ratio; however this still can allow small fluctuations in CO effects of ambient CO
2
2
concentration during the course of the day. To completely remove all
from the analyzer’s measurement of CO into the GFC wheel housing to purge all ambient CO
2
2
, dried air, scrubbed of all CO
(see Figure 10-7)
2
is pumped
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9.2. Pneumatic Operation
CAUTION
It is important that the sample airflow system is both leak tight and not pressurized over ambient pressure.
Regular leak checks should be performed on the analyzer as described in the maintenance schedule, Table 9-1.
Procedures for correctly performing leak checks can be found in Section 9.3.3.
An internal pump evacuates the sample chamber creating a small vacuum that draws sample gas into the analyzer. Normally the analyzer is operated with its inlet near ambient pressure either because the sample is directly drawn at the inlet or a small vent is installed at the inlet. There are several advantages to this “pull through” configuration.
By placing the pump down stream from the sample chamber several problems are avoided.
First the pumping process heats and compresses the sample air complicating the measurement process.
Additionally, certain physical parts of the pump itself are made of materials that might chemically react with the sample gas.
Finally, in certain applications where the concentration of the target gas might be high enough to be hazardous, maintaining a negative gas pressure relative to ambient means that should a minor leak occur, no sample gas will be pumped into the atmosphere surrounding analyzer.
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Theory of Operation
9.2.1. Sample Gas Flow
Model GFC7000TA Carbon Dioxide Analyzer
Sample Gas
Flow Control
CO
2
FLOW
SENSOR
SAMPLE
PRESSURE
SENSOR
Purge Gas
Pressure Control
Figure 9-7: Internal Pneumatic Flow – Basic Configuration
9.2.2. Flow Rate Control
To maintain a constant flow rate of the sample gas through the instrument, the Model GFC 7000TA uses special flow control assemblies located in the purge gas line at the entrance to the GFC wheel housing and in the exhaust gas line just before the pump (see Figure 10-7). These assemblies consists of:
A critical flow orifice.
Two o-rings: Located just before and after the critical flow orifice, the o-rings seal the gap between the walls of assembly housing and the critical flow orifice.
A spring: Applies mechanical force needed to form the seal between the o-rings, the critical flow orifice and the assembly housing.
9.2.2.1. Critical Flow Orifice
The most important component of this flow control assembly is the critical flow orifice.
Critical flow orifices are a remarkably simple way to regulate stable gas flow rates. They operate without moving parts by taking advantage of the laws of fluid dynamics. By restricting the flow of gas though the orifice, a pressure differential is created. This pressure differential combined with the action of the analyzer’s pump draws the gas through the orifice.
As the pressure on the downstream side of the orifice (the pump side) continues to drop, the speed that the gas flows though the orifice continues to rise. Once the ratio of upstream pressure to downstream
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer pressure is greater than 2:1, the velocity of the gas through the orifice reaches the speed of sound. As long as that ratio stays at least 2:1 the gas flow rate is unaffected by any fluctuations, surges, or changes in downstream pressure because such variations only travel at the speed of sound themselves and are therefore cancelled out by the sonic shockwave at the downstream exit of the critical flow orifice.
CRITICAL
FLOW
ORIFICE
AREA OF
HIGH
PRESSURE
AREA OF
LOW
PRESSURE
SPRING
FILTER
Sonic
Shockwave
O-RINGS
Figure 9-8: Flow Control Assembly & Critical Flow Orifice
The actual flow rate of gas through the orifice (volume of gas per unit of time), depends on the size and shape of the aperture in the orifice. The larger the hole, the more gas molecules, moving at the speed of sound, pass through the orifice. Because the flow rate of gas through the orifice is only related to the minimum 2:1 pressure differential and not absolute pressure the flow rate of the gas is also unaffected by degradations in pump efficiency due to age.
The critical flow orifice used in the Model GFC 7000TA is designed to provide a flow rate of 800 cm
3
/min.
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9.2.3. Purge Gas Pressure Control
In order to ensure that all of the ambient CO
2 of dried air, scrubbed of CO
2
is purged from the GFC Wheel housing an adequate supply
must be supplied to the PURGE AIR inlet at the back of the instrument.
The minimum gas pressure of the source of purge air should be 7.5 psig.
If the source of the purge air is shared by a Teledyne TAI’s T700 (as shown in figure 3-7) the minimum gas pressure should be 25 psig and should not exceed 35 psig.
In order to maintain the proper pressure differential between the inside of the GFC wheel housing and ambient air, the GFC 7000TA design includes a manually adjustable pressure regulator (see Figure 3-5 and Figure 3-6 for
Purge Gas Pressure Regulator
) that maintains the pressure of the purge air feed at 7.5 psig.
9.2.4. Particulate Filter
The Model GFC 7000TA Analyzer comes equipped with a 47 mm diameter, Teflon, particulate filter with a
5 micron pore size. The filter is accessible through the front panel, which folds down to allow access, and should be changed according to the suggested maintenance schedule described in Table 9-1.
9.2.5. Pneumatic Sensors
9.2.5.1. Sample Pressure Sensor
An absolute value pressure transducer plumbed to the outlet of the sample chamber is used to measure sample pressure. The output of the sensor is used to compensate the concentration measurement for changes in air pressure. This sensor is mounted to a printed circuit board with the sample flow sensor on the sample chamber; see the following section and Figure 3-3.
9.2.5.2. Sample Flow Sensor
A thermal-mass flow sensor is used to measure the sample flow through the analyzer. The sensor is calibrated at the factory with ambient air or N
2
, but can be calibrated to operate with samples consisting of other gases such as CO
2
, See Section 9.3.4. This sensor is mounted to a printed circuit board with the
Sample Pressure sensor on the sample chamber; see the previous section and Figure 3-3.
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9.3. Electronic Operation
9.3.1. Overview
Figure 10-9 shows a block diagram of the major electronic components of the Model GFC 7000TA.
The core of the analyzer is a microcomputer/central processing unit (CPU) that controls various internal processes, interprets data, makes calculations, and reports results using specialized firmware developed by Teledyne Instruments. It communicates with the user as well as receives data from and issues commands to a variety of peripheral devices via a separate printed circuit assembly called the Mother
Board.
The mother board, directly mounted to the analyzer’s inside rear panel, collects data, performs signal conditioning duties and routs incoming and outgoing signals between the CPU and the analyzer’s other major components.
Data is generated by a gas-filter-correlation optical bench which outputs an analog signal corresponding to the concentration of CO in the sample gas. This analog signal is transformed into two, pre-amplified,
2
DC voltages (CO2 MEAS and CO2 REF) by a synchronous demodulator printed circuit assembly. CO2
MEAS and CO2 REF are converted into digital data by a unipolar, analog-to-digital converter, located on the mother board.
A variety of sensors report the physical and operational status of the analyzer’s major components, again through the signal processing capabilities of the mother board. These status reports are used as data for the CO
2
concentration calculation and as trigger events for certain control commands issued by the CPU.
They are stored in memory by the CPU and in most cases can be viewed but the user via the front panel display.
The CPU communicates with the user and the outside world in a variety of manners:
Through the analyzer’s touchscreen and LCD display over a clocked, digital, serial I/O bus (using a protocol called I 2 C)
RS 232 & RS485 Serial I/O channels via Ethernet, Modbus ® , Apicom or a terminal emulation program
Various DCV and DCA analog outputs, and
Several sets of Digital I/O channels.
Finally, the CPU issues commands via a series of relays and switches (also over the I 2 C bus) located on a separate printed circuit assembly to control the function of key electromechanical devices such as heaters, motors and valves.
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Theory of Operation
A1
A2
Analog Outputs
Optional
4-20 mA
A3
A4
Power-Up
Circuit
Analog
Outputs
(D/A)
Model GFC7000TA Carbon Dioxide Analyzer
Analog In
RS232
Male
COM2
Female
USB COM port Ethernet
Control Inputs:
1 – 8
Status Outputs:
1 – 6
External
Digital I/O)
A/D
Converter
(V/F)
(I 2 C Bus)
Touchscreen
Display
LVDS transmitter board
PC 104
CPU Card
Disk On
Module
MOTHER
BOARD
Box
Temp
Flash Chip
PC 104 Bus
SAMPLE
TEMP
Thermistor
Interface
Internal
Digital I/O Sensor Inputs
CO
2
M
E
A
S
CO
2
R
E
F
Optional
O
2
Sensor
Sample Flow
& Pressure
Sensors
I 2 C
Bus
BENCH
TEMP
WHEEL
TEMP
O
2
SENSOR
TEMP
(optional)
SYNC
DEMOD
Schmidt
Trigger
TEC Control
PHT
Drive
Photodetector
Detector
Output
GFC
Wheel
Optical
Bench
Segment Sensor
M / R Sensor
Figure 9-9: GFC 7000TA Electronic Block Diagram
Zero/Span
Valve
Options
IR
Source
PUMP
RELAY
BOARD
CPU Status
LED
GFC
Motor
Wheel
Heater
Bench Heater
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.3.2. CPU
The unit’s CPU card, installed on the motherboard inside the rear panel, is a low power (5 VDC, 720mA max), high performance, Vortex 86SX-based microcomputer running Windows CE. Its operation and assembly conform to the PC/104 specification.
Figure 9-10: CPU Board
The CPU includes two types of non-volatile data storage: a Disk on Module (DOM) and an embedded flash chip.
9.3.2.1. Disk-On-Module (DOM)
The DOM is a 44-pin IDE flash chip with storage capacity to 129 MB. It is used to store the operating system, the Teledyne firmware, and most of the operational data generated by the analyzer’s internal data acquisition system (DAS - See Section 6.7).
9.3.2.2. Flash Chip
This non-volatile, embedded flash chip includes 2MB of storage for calibration data as well as a backup of the analyzer configuration. Storing these key data on a separate, less heavily accessed chip significantly decreases the chance of data corruption. In the unlikely event that the flash chip should fail, the analyzer will continue to operate with just the DOM. However, all configuration information will be lost, requiring that the unit be recalibrated.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.3.3. Optical Bench & GFC Wheel
Electronically, the Model GFC 7000TA’s optical bench, GFC wheel and associated components do more than simply measure the amount of CO
2 functions are performed here as well.
present in the sample chamber. A variety of other critical
9.3.3.1. Temperature Control
Because the temperature of a gas affects its density and therefore the amount of light absorbed by that gas it is important to reduce the effect of fluctuations in ambient temperature on the Model GFC 7000TA’s measurement of CO
2
. To accomplish this the temperature of both the sample chamber and the GFC
Wheel are maintained at constant temperatures above their normal operating ranges.
Bench Temperature: To minimize the effects of ambient temperature variations on the sample measurement, the sample chamber is heated to 48 C (8 degrees above the maximum suggested ambient operating temperature for the analyzer). The heat source is a strip heater attached to the underside of the chamber housing. The temperature of the sample chamber is sensed by a thermistor attached to the sample chamber housing.
Wheel Temperature: To minimize the effects of temperature variations caused by the near proximity of the IR Source to the GFC wheel on the gases contained in the wheel, it is also raised to a high temperature level. Because the IR Source itself is very hot, the set point for this heat circuit is 68 C. The heat source is a cartridge heater implanted into the heat sync on the motor. The temperature of the wheel/motor assembly is sensed by a thermistor inserted into the heat sync.
Both heaters operate off of the AC line voltage supplied to the instrument.
9.3.3.2. IR Source
The light used to detect CO
1100 o
2
in the sample chamber is generated by an element heated to approximately
C producing infrared radiation across a broad band. This radiation is optically filtered after it has passed through the GFC Wheel and the sample chamber and just before it reaches the photo-detector to eliminate all black body radiation and other extraneous IR emitted by the various components of those components.
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9.3.3.3. GFC Wheel
A synchronous AC motor turns the GFC wheel motor. For analyzers operating on 60Hz line power this motor turns at 1800 rpm. For those operating on 50Hz line power the spin rate is 1500 rpm. The actual spin rate is unimportant within a large rate since a phase lock loop circuit is used to generate timing pulses for signal processing.
In order to accurately interpret the fluctuations of the IR beam after it has passed through the sample gas, the GFC wheel several other timing signals are produced by other photo emitters/detectors. These devices consist of a combination LED and detector mounted so that the light emitted by the LED shines through the same mask on the GFC wheel that chops the IR beam.
KEY:
Detection Beam shining through MEASUREMENT side of GFC Wheel
Detection Beam shining through REFERENCE side of GFC Wheel
IR Detection Ring
Segment Sensor Ring
M/R Sensor Ring
Figure 9-11: GFC Light Mask
M/R Sensor
This emitter/detector assembly that produces a signal that shines through a portion of the mask that allows light to pass for half of a full revolution of the wheel. The resulting light signal tells the analyzer whether the IR beam is shining through the measurement or the reference side of the GFC wheel.
Segment Sensor
Light from this emitter/detector pair shines through a portion of the mask that is divided into the same number of segments as the IR detector ring. It is used by the synchronous / demodulation circuitry of the analyzer to latch onto the most stable part of each measurement and reference IR pulse.
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Measurement
Pulses
Reference
Pulses
IR Beam
Pulses
Segment Sensor
Pulses
MR Sensor
Pulses
Figure 9-12: Segment Sensor and M/R Sensor Output
Schmidt Triggers
To ensure that the waveforms produced by the Segment Sensor and the M/R Sensor are properly shaped and clean, these signals are passed through a set of Schmidt Triggers circuits.
9.3.3.4. IR Photo-Detector
The IR beam is converted into an electrical signal by a cooled solid-state photo-conductive detector. The detector is composed of a narrow-band optical filter, a piece of lead-salt crystal whose electrical resistance changes with temperature, and a two-stage thermo-electric cooler.
When the analyzer is on, a constant electrical current is directed through the detector, The IR beam is focused onto the detector surface, raising its temperature and lowering its electrical resistance that results in a change in the voltage drop across the detector.
During those times that the IR beam is bright, the temperature of the detector is high; the resistance of the detector is correspondingly low and the its output voltage output is low. During those times when the
IR beam intensity is low or completely blocked by the GFC Wheel mask, the temperature of the detector is lowered by the two-stage thermo-electric cooler, increasing the detectors resistance and raising the output voltage.
9.3.4. Synchronous Demodulator (Sync/Demod) Assembly
9.3.4.1. Overview
While the photo-detector converts fluctuations of the IR beam into electronic signals, the Sync / Demod
Board amplifies these signals and converts them into usable information. Initially the output by the photodetector is a complex and continuously changing waveform made up of Measure and Reference pulses.
The sync/demod board demodulates this waveform and outputs two analog DC voltage signals, corresponding to the peak values of these pulses. CO2 MEAS and CO2 REF are converted into digital signals by circuitry on the motherboard then used by the CPU to calculate the CO
2
concentration of the sample gas.
Additionally the synch/demod board contains circuitry that controls the photo-detector’s thermoelectric cooler as well as circuitry for performing certain diagnostic tests on the analyzer.
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Theory of Operation
56V
Bias
Model GFC7000TA Carbon Dioxide Analyzer
Photodetector
Pre Amp
TEC Control
PHT DRIVE
Dark
Switch
E-Test
Generator
Variable
Gain Amp
Sample &
Hold
Circuits
(x4)
Signal
Conditioner
CO
2
MEAS
CO
2
Reference
M/R Sensor
Segment
Sensor
E Test Control
Dark Switch
Control
Thermo-Electric
Cooler
Control Circuit
Compact
Programmable
Logic Device
E Test A Gate
E Test B Gate
Dark Test Gate
Measure Gate
Measure Dark Gate
Reference Gate
Reference Dark Gate
From GFC
Wheel
From CPU via Mother
Board
10
Segment Clock
X1 Reference
X10 Clock
Phase Lock x10
Phase
Lock
Loop
Phase Lock Warning
M/R
Status LED
Segment
Status LED
Figure 9-13: GFC 7000TA Sync / Demod Block Diagram
9.3.4.2. Signal Synchronization and Demodulation
The signal emitted by the IR photo-detector goes through several stages of amplification before it can be accurately demodulated. The first is a pre-amplification stage that raises the signal to levels readable by the rest of the synch/demod board circuitry. The second is a variable amplification stage that is adjusted at the factory to compensate for performance variations of mirrors, detectors, and other components of the optical bench from instrument to instrument.
The workhorses of the sync/demod board are the four sample-and-hold circuits that capture various voltage levels found in the amplified detector signal needed to determine the value of CO2 MEAS and
CO2 REF . They are activated by logic signals under the control of a compact programmable logic device
(PLD), which in turn responds to the output of the Segment Sensor and M/R Sensor described in
Figure 10–11.
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Theory of Operation
The four sample and hold circuits are:
Model GFC7000TA Carbon Dioxide Analyzer
Measure Gate
Measure Dark Gate
Reference Gate
Reference Dark Gate
IR BEAM PASSING THROUGH
MEASUREMENT cell of GFC Wheel
MEASUREMENT cell of GFC Wheel
REFERENCE cell of GFC Wheel
REFERENCE cell of GFC Wheel
SEGMENT SENSOR PULSE IS:
HIGH
LOW
HIGH
LOW
Timing for activating the Sample and Hold circuits is provided by a phase lock loop circuit (PLL). Using the segment sensor output as a reference signal the PLL generates clock signal at ten times that frequency. This faster clock signal is used by the PLD to make the sample and hold circuits capture the signal during the center portions of the detected waveform, ignore the rising and falling edges of the detector signal.
Sample & Hold
Active
Detector
Output
Sample & Hold
Inactive
Figure 9-14: Sample & Hold Timing
9.3.4.3. Sync/Demod Status LED’s
The following two status LED’s located on the synch/demod board provide additional diagnostic tools for checking the GFC wheel rotation.
Table 9-1: Sync/Demod Status LED Activity
LED
D1
FUNCTION
M/R Sensor Status
D2
Segment Sensor
Status
See Section 11.1.4 for more information.
STATUS OK
LED flashes approximately
2/second
LED flashes approximately
6/second
FAULT STATUS
LED is stuck
ON or OFF
LED is stuck
ON or OFF
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9.3.4.4. Photo-Detector Temperature Control
The synch/demod board also contains circuitry that controls the IR photo-detector’s thermoelectric coolers. A drive voltage, PHT DRIVE, is supplied to the coolers by the synch/demod board which is adjusted by the synch/demod board based on a return signal called TEC control which alerts informs the synch/demod board of the detector’s temperature. The warmer the detector, the harder the coolers are driven.
PHT DRIVE is one of the Test Functions viewable by the user via the front panel. Press <TST or TST> until it appears on the display.
9.3.4.5. Dark Calibration Switch
This switch initiates the Dark Calibration procedure. When initiated by the user (See Section 6.13.6 for more details), the dark calibration process opens this switch, interrupting the signal from the IR photodetector. This allows the analyzer to measure any offset caused by the synch/demod board circuitry.
9.3.4.6. Electric Test Switch
When active this circuit generates a specific waveform intended to simulate the function of the IR photodetector but with a known set of value which is substituted for the detector’s actual signal via the dark switch. It may also be initiated by the user (See Section 6.13.5 for more details).
9.3.5. Relay Board
By actuating various switches and relays located on this board, the CPU controls the status of other key components. The relay board receives instructions in the form of digital signals over the I
2
C bus, interprets these digital instructions and activates its various switches and relays appropriately.
9.3.5.1. Heater Control
The two heaters attached to the sample chamber housing and the GFC wheel motor are controlled by solid state relays located on the relay board.
The GFC wheel heater is simply turned on or off, however control of the bench heater also includes circuitry that selects which one of its two separate heating elements is activated depending on whether the instrument is running on 100 VAC, 115 VAC or 230 VAC line power.
9.3.5.2. GFC Wheel Motor Control
The GFC wheel operates from an AC voltage supplied by a multi-input transformer located on the relay board. The step-down ratio of this transformer is controlled by factory-installed jumpers to adjust for 100
VAC, 115 VAC or 230 VAC line power. Other circuitry slightly alters the phase of the AC power supplied to the motor during start up based on whether line power is 50Hz or 60 Hz.
Normally, the GFC Wheel Motor is always turning while the analyzer is on. A physical switch located on the relay board can be used to turn the motor off for certain diagnostic procedures.
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Theory of Operation
9.3.5.3. Zero/Span Valve Options
Model GFC7000TA Carbon Dioxide Analyzer
Any zero/span valve options installed in the analyzer are controlled by a set of electronic switches located on the relay board. These switches, under CPU control, supply the +12VDC needed to activate each valve’s solenoid.
9.3.5.4. IR Source
The Relay board supplies a constant 11.5VDC to the IR Source. Under normal operation the IR source is always on.
9.3.5.5. Status LEDs
Eight LEDs are located on the analyzer’s relay board to show the current status on the various control functions performed by the relay board (see Figure 10-14). They are:
Table 9-2: Relay Board Status LED’s
STATUS WHEN UNLIT LED COLOR FUNCTION STATUS WHEN LIT
D2
D3
YELLOW
YELLOW
Wheel Heater
Bench Heater
D7 GREEN Shutoff Valve
Option
D8 GREEN IR SOURCE analyzer’s CPU.
HEATING
HEATING
D4 YELLOW Spare N/A
D5 GREEN Sample/Cal Gas
Valve Option
D6 GREEN Zero/Span Gas
Valve Option
Valve Open to CAL GAS
FLOW
Valve Open to SPAN GAS
FLOW
Valve Open to CAL GAS
FLOW
Source ON
NOT HEATING
NOT HEATING
N/A
Valve Open to SAMPLE GAS
FLOW
Valve Open to ZERO GAS FLOW
Valve CLOSED to CAL GAS
FLOW
Source OFF
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Theory of Operation
STATUS LED’s
Model GFC7000TA Carbon Dioxide Analyzer
DC VOLTAGE TEST
POINTS
RELAY PCA
Figure 9-15: Location of relay board Status LED’s
9.3.5.6.
I
2
C
Watch Dog Circuitry
Special circuitry on the relay board monitors the activity on the
I
2
C
bus and drives LED D1. Should this
LED ever stay ON or OFF for 30 seconds, the watchdog circuit will automatically shut of all valves as well as turn off the IR Source and all heaters. The GFC wheel motor will still be running as will the Sample
Pump, which is not controlled by the relay board.
9.3.6. Mother Board
This printed circuit assembly provides a multitude of functions including, A/D conversion, digital input/output, PC-104 to I2C translation, temperature sensor signal processing and is a pass through for the RS-232 and RS-485 signals.
9.3.6.1. A to D Conversion
Analog signals, such as the voltages received from the analyzer’s various sensors, are converted into digital signals that the CPU can understand and manipulate by the analog to digital converter (A/D).
Under the control of the CPU, this functional block selects a particular signal input (e.g. BOX TEMP, CO2
MEAS , CO2 REF, etc.) and then coverts the selected voltage into a digital word.
The A/D consists of a voltage-to-frequency (V-F) converter, a programmable logic device (PLD), three multiplexers, several amplifiers and some other associated devices. The V-F converter produces a frequency proportional to its input voltage. The PLD counts the output of the V-F during a specified time period, and sends the result of that count, in the form of a binary number, to the CPU.
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The A/D can be configured for several different input modes and ranges but in the GFC 7000TA is used in uni-polar mode with a +5 V full scale. The converter includes a 1% over and under-range. This allows signals from –0.05 V to +5.05 V to be fully converted.
For calibration purposes, two reference voltages are supplied to the A/D converter: Reference Ground and +4.096 VDC. During calibration, the device measures these two voltages, outputs their digital equivalent to the CPU. The CPU uses these values to compute the converter’s offset and slope and uses these factors for subsequent conversions.
See Section 6.13.4 for instructions on performing this calibration.
9.3.6.2. Sensor Inputs
The key analog sensor signals are coupled to the A/D through the master multiplexer from two connectors on the motherboard. 100K terminating resistors on each of the inputs prevent cross talk from appearing on the sensor signals.
CO
2
Measure and Reference
These are the primary signals that are used in the computation of the CO
2 demodulated IR-sensor signals from the sync demodulator board.
concentration. They are the
Sample Pressure and Flow
These are analog signals from two sensors that measure the pressure and flow rate of the gas stream at the outlet of the sample chamber. This information is used in two ways. First, the sample pressure is used by the CPU to calculate CO
2
Concentration. Second, the pressure and flow rate are monitored as a test function to assist the user in predicting and troubleshooting failures.
9.3.6.3. Thermistor Interface
This circuit provides excitation, termination and signal selection for several negative-coefficient, thermistor temperature sensors located inside the analyzer. They are:
Sample Temperature Sensor
The source of this signal is a thermistor located inside the sample chamber of the Optical Bench. It measures the temperature of the sample gas in the chamber. This data is used to during the calculation of the CO
2
concentration value.
Bench Temperature Sensor
This thermistor, attached to the sample chamber housing, reports the current temperature of the chamber housing to the CPU as part of the bench heater control loop.
Wheel Temperature Sensor
This thermistor (attached to the heat-sync on the GFC wheel motor assembly) reports the current temperature of the wheel/motor assembly to the CPU as part of the Wheel Heater control loop.
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Theory of Operation
Box Temperature Sensor
Model GFC7000TA Carbon Dioxide Analyzer
A thermistor is attached to the motherboard. It measures the analyzer’s inside temperature. This information is stored by the CPU and can be viewed by the user for troubleshooting purposes via the front panel display (See Section 11.1.2).
9.3.6.4. Analog Outputs
The analyzer comes equipped with four analog outputs: A1, A2, A3 and A4. . In its standard configuration, the analyzer comes with all four of these channels set up to output a DC voltage. However,
4-20mA current loop drivers can be purchased for the first three of these outputs: A2, A2 & A3.
A2 and A1 Output
The first two, A2 and A1 are normally set up to operate in parallel so that the same data can be sent to two different recording devices. While the names imply that one should be used for sending data to a chart recorder and the other for interfacing with a data logger, either can be used for both applications.
Both of these channels output a signal that is proportional to the CO
2
concentration of the sample gas.
The A1 and A2 outputs can be slaved together or set up to operated independently. A variety of scaling factors are available, See Section 6.13.4 for information on setting the range type and scaling factors for these output channels.
A3 Output
Analog output channel A3 is only active when the O case, the currently measured O
2
2 sensor option is installed in the GFC 7000TA. In this
concentration is output.
Test Function Output
The fourth analog output, labeled A4 is special. It can be set by the user (See Section 6.9.9) to carry the current signal level of any one of the parameters accessible through the SETUP MORE DIAG
TEST CHAN OUTPUT submenu (See Section 6.13.9) of the unit’s software.
Output Loop-back
All four analog outputs are connected back to the A/D converter through a Loop-back circuit. This permits the voltage outputs to be calibrated by the CPU without need for any additional tools or fixtures.
9.3.6.5. Internal Digital I/O
This channel is used to communicate digital status and control signals about the operation of key components of the Optical Bench. The CPU sends signals to the synch/demod board that initiate the
ELECTRICAL TEST and DARK CALIBRATION procedures. Likewise, the synch/demod board uses this interface to send the SYNC warning signal to the CPU (See Sections 6.9.5, 6.9.6 and 11.1.1).
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Theory of Operation
9.3.6.6. External Digital I/O
Model GFC7000TA Carbon Dioxide Analyzer
This External Digital I/O performs two functions: status outputs and control inputs.
Status Outputs
Logic-Level voltages are output through an optically isolated 8-pin connector located on the rear panel of the analyzer. These outputs convey good/bad and on/off information about certain analyzer conditions.
They can be used to interface with certain types of programmable devices (See Section 6.13.1.1).
Control Inputs
By applying +5VDC power supplied from an external source such as a PLC or Data logger (See Section
6.13.1.2), Zero and Span calibrations can be initiated by contact closures on the rear panel.
9.3.7. I
2
C Data Bus
An I
2
C data bus is used to communicate data and commands between the CPU and the touchscreen/display interface and the relay board. I 2 C is a two-wire, clocked, digital serial I/O bus that is used widely in commercial and consumer electronic systems. A transceiver on the motherboard converts data and control signals from the PC-104 bus to I interface and finally onto the relay board.
2
C. The data is then fed to the touchscreen/display
Interface circuits on the touchscreen/display interface and relay boards convert the I 2 C data to parallel inputs and outputs. An additional, interrupt line from the touchscreen to the motherboard allows the CPU to recognize and service button presses on the touchscreen.
Power up Circuit
This circuit monitors the +5V power supply during start-up and sets the Analog outputs, external digital
I/O ports, and I
2
C circuitry to specific values until the CPU boots and the instrument software can establish control.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.3.8. Power Supply/ Circuit Breaker
The analyzer operates on 100 VAC, 115 VAC or 230 VAC power at either 50Hz or 60Hz. Individual units are set up at the factory to accept any combination of these five attributes. As illustrated in Figure 10-15, power enters the analyzer through a standard IEC 320 power receptacle located on the rear panel of the instrument. From there it is routed through the On/Off switch located in the lower right corner of the Front
Panel. A 6.75 Amp circuit breaker is built into the ON/OFF Switch.
AC power is distributed directly to the sample gas pump. The bench and GFC wheel heaters as well as the GFC wheel receive AC power via the relay board.
AC Line power is converted stepped down and converted to DC power by two DC power supplies. One supplies +12 VDC, for valves and the IR source, while a second supply provides +5 VDC and ±15 VDC for logic and analog circuitry. All DC voltages are distributed via the relay board.
CAUTION
Should the AC power circuit breaker trip, investigate and correct the condition causing this situation before turning the analyzer back on.
ON/OFF
SWITCH Touchscreen
Display
Pressure
Sensors
AC POWER
ENTRANCE
LVDS transmittedr board
RELAY
BOARD
PS 1 (+5 VDC; ±15 VDC)
CPU
Mother
Board
Sync/Demod
PS 2 (+12 VDC)
KEY
AC POWER
DC POWER
IR Source
Cooling Fan
M/R &
Segment
Sensors
Valve Options Heaters
GFC Wheel
Motor
Pump
Figure 9-16: Power Distribution Block Diagram
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.4. Front Panel Touchscreen/Display Interface
Users can input data and receive information directly through the front panel touchscreen display. The
LCD display is controlled directly by the CPU board. The touchscreen is interfaced to the CPU by means of a touchscreen controller that connects to the CPU via the internal USB bus and emulates a computer mouse.
Figure 9-17: Front Panel and Display Interface Block Diagram
9.4.1. LVDS Transmitter Board
The LVDS (low voltage differential signaling) transmitter board converts the parallel display bus to a serialized, low voltage, differential signal bus in order to transmit the video signal to the LCD interface
PCA.
9.4.2. Front Panel Touchscreen/Display Interface PCA
The front panel touchscreen/display interface PCA controls the various functions of the display and touchscreen. For driving the display it provides connection between the CPU video controller and the
LCD display module. This PCA also contains:
power supply circuitry for the LCD display module
a USB hub that is used for communications with the touchscreen controller and the two front panel
USB device ports
the circuitry for powering the display backlight
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.5. Software Operation
The Model GFC 7000TA Gas Filter Correlation Carbon Dioxide Analyzer has a high performance,
VortexX86-based microcomputer running Windows CE. Inside Windows CE, special software developed by Teledyne Instruments interprets user commands via the various interfaces, performs procedures and tasks, stores data in the CPU’s various memory devices and calculates the concentration of the sample gas.
Windows CE
API FIRMWARE
Memory Handling
DAS Records
Calibration Data
System Status Data
Analyzer Operations
Calibration Procedures
Configuration Procedures
Autonomic Systems
Diagnostic Routines
PC/104 BUS
ANALYZER
HARDWARE
Measurement
Algorithm
Interface Handling
Sensor input Data
Touchscreen/Display
Analog Output Data
RS232 & RS485
External Digital I/O
PC/104 BUS
Linearization Table
Figure 9-18: Basic Software Operation
9.5.1. Adaptive Filter
The GFC 7000TA software processes the CO2 MEAS and CO2 REF signals, after they are digitized by the motherboard, through an adaptive filter built into the software. Unlike other analyzers that average the output signal over a fixed time period, the GFC 7000TA averages over a set number of samples, where each sample is 0.2 seconds. This is technique is known as boxcar averaging. During operation, the software automatically switches between two different length filters based on the conditions at hand.
Once triggered, the short filter remains engaged for a fixed time period to prevent chattering.
During conditions of constant or nearly constant concentration the software, by default, computes an average of the last 750 samples, or approximately 150 seconds. This provides the calculation portion of the software with smooth stable readings. If a rapid change in concentration is detected the filter
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer includes, by default, the last 48 samples, approximately 10 seconds of data, to allow the analyzer to more quickly respond. If necessary, these boxcar lengths can be changed between 1 and 1000 samples but with corresponding tradeoffs in rise time and signal-to-noise ratio (contact customer service for more information).
Two conditions must be simultaneously met to switch to the short filter. First the instantaneous concentration must exceed the average in the long filter by a fixed amount. Second the instantaneous concentration must exceed the average in the long filter by a portion, or percentage, of the average in the long filter.
9.5.2. Calibration - Slope and Offset
Calibration of the analyzer is performed exclusively in software.
During instrument calibration (see Section 7) the user enters expected values for zero and span via the front panel touchscreen and commands the instrument to make readings of calibrated sample gases for both levels. The readings taken are adjusted, linearized, and compared to the expected values, With this information the software computes values for instrument slope and offset and stores these values in memory for use in calculating the CO
2
concentration of the sample gas.
The instrument slope and offset values recorded during the last calibration can be viewed by pressing the following touchscreen button sequence:
SAMPLE
=XX.XX
RANGE = 50.0 MGM CO2
SAMPLE
=XX.XX
TIME = 16:23:34 CO2
SAMPLE
=XX.XX
OFFSET = 0.000 CO2
SAMPLE
=XX.XX
SLOPE = 1.000 CO2
9.5.3. Measurement Algorithm
Once the IR photo-detector is signal is demodulated into CO2 MEAS and CO2 REF by the sync/demod board and converted to digital data by the motherboard the GFC 7000TA analytical software calculates the ratio between CO2 MEAS and CO2 REF. This value is compared to a look-up table is used, with interpolation, to linearize the response of the instrument. The linearized concentration value is combined with calibration slope and offset values, then normalized for changes in sample gas pressure to produce the final CO
2
concentration. This is the value that is displayed on the instrument front panel display and is stored in memory by the analyzer’s DAS system.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
9.5.4. Temperature and Pressure Compensation
Changes in pressure can have a noticeable, effect on the CO
2
2
calculations based on changes in ambient pressure.
concentration calculation. To account for this, the Model GFC 7000TA software includes a feature which allows the instrument to compensation of the CO
The TPC feature multiplies the analyzer’s CO
2
concentration by a factor which is based on the difference between the ambient pressure of the sample gas normalized to standard atmospheric pressure. As ambient pressure increases, the compensated CO
2
concentration is increased.
9.5.5. Internal Data Acquisition System (DAS)
The DAS is designed to implement predictive diagnostics that stores trending data for users to anticipate when an instrument will require service. Large amounts of data can be stored in non-volatile memory and retrieved in plain text format for further processing with common data analysis programs. The DAS has a consistent user interface in all Teledyne Instruments analyzers. New data parameters and triggering events can be added to the instrument as needed.
Depending on the sampling frequency and the number of data parameters the DAS can store several months of data, which are retained even when the instrument is powered off or a new firmware is installed. The DAS permits users to access the data through the instrument’s front panel or the remote interface. The latter can automatically download stored data for further processing. For information on using the DAS, refer to Sections 6.12.
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Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
10. TROUBLESHOOTING & REPAIR PROCEDURES
This contains a variety of methods for identifying the source of performance problems with the analyzer.
Also included in this are procedures that are used in repairing the instrument.
CAUTION
The operations outlined in this section are to be performed by qualified maintenance personnel only.
CAUTION
Risk of electrical shock. Disconnect power before performing the following operations.
10.1. General Troubleshooting Hints
The analyzer has been designed so that problems can be rapidly detected, evaluated and repaired.
During operation, the analyzer continuously performs self-check diagnostics and provides the ability to monitor the key operating parameters of the instrument without disturbing monitoring operations.
A systematic approach to troubleshooting will generally consist of the following four steps: any and take corrective action as required.
2. Examine the values of all TEST functions and compare to factory values. Note any major deviations from the factory values and take correction action as required.
3. Use the internal electronic status LED’s to determine whether the CPU and I
2
C buses are running, and if the sync/demodulator and relay board are operating properly. Verify that the DC power supplies are operating properly by checking the voltage test points on the relay board.
Please note that the analyzer’s DC power wiring is color-coded and these colors match the color of the corresponding test points on the relay board.
4. SUSPECT A LEAK FIRST! Data from Teledyne Instruments’ service department indicates that
50% of all problems are eventually traced to leaks in the pneumatic connections and gas lines of the analyzer itself, the source of zero air, span gases or sample gas delivery system.
Check for gas flow problems such as clogged or blocked internal/external gas lines, damaged seals, punctured gas lines, a damaged pump diaphragm, etc.
5. Follow the procedures defined in Section 11.5 for confirming that the analyzer’s basic components are working (power supplies, CPU, relay board, sync/demod board, touchscreen/display, GFC wheel motor, etc.). See Figure 3-3 for general layout of components and sub-assemblies in the analyzer. See the wiring list and diagram in Appendix D of this manual.
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
10.1.1. Interpreting WARNING Messages
The most common and/or serious instrument failures will result in a warning message being displayed on the front panel. Table 11-1 lists warning messages, along with their meaning and recommended corrective action.
It should be noted that if more than two or three warning messages occur at the same time, it is often an indication that some fundamental analyzer sub-system (power supply, relay board, motherboard) has failed rather than indication of the specific failures referenced by the warnings. In this case, it is recommended that proper operation of power supplies (See Section 10.5.2), the relay board (See Section
10.5.6), and the A/D Board (See Section11.4.7.1) be confirmed before addressing the specific warning messages.
The analyzer will alert the user that a Warning message is active by flashing the FAULT LED and displaying the Warning message in the Param field along with the CLR button (press to clear Warning message). The MSG button displays if there is more than one warning in queue or if you are in the TEST menu and have not yet cleared the message. The following display/touchscreen examples provide an illustration of each:
The analyzer will also alert the user via the Serial I/O COM port(s) and cause the FAULT LED on the front panel to blink.
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To view or clear the various warning messages press:
TEST deactivates Warning
Messages until New warning(s) are activated
SAMPLE
TEST
WHEEL TEMP WARNING CO2 = XX.XX
CAL MSG CLR SETUP
SAMPLE RANGE=500.00 PPM CO2 = XX.XX
< TST TST > CAL MSG CLR SETUP
MSG activates Warning
Messages.
<TST TST > keys replaced with
TEST key
SAMPLE WHEEL TEMP WARNING
< TST TST > CAL MSG
CO2 = XX.XX
CLR SETUP
Make sure warning messages are not due to legitimate problems..
Figure 10-1: Viewing and Clearing Warning Messages
Press CLR to clear the message currently being
Displayed.
If more than one warning is active the next message will take its place
Once the last warning has been cleared, the analyzer returns to
SAMPLE Mode
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Table 10-1: Warning Messages - Indicated Failures
WARNING
MESSAGE
BENCH TEMP
WARNING
BOX TEMP
WARNING
CANNOT DYN
SPAN
CANNOT DYN
ZERO
CONFIG
INITIALIZED
CONC ALRM1
WARNING
CONC ALRM2
WARNING
FAULT CONDITION
The optical bench temp is controlled at 48 2 °
C.
Box Temp is
< 5
°
C or > 48
°
C.
Dynamic Span operation failed
Dynamic Zero operation failed
Configuration and Calibration data reset to original Factory state.
Concentration alarm 1 is enabled and the measured CO
2
level is ≥ the set point.
Concentration alarm 2 is enabled and the measured CO
2
level is ≥ the set point.
POSSIBLE CAUSES
Bad bench heater
Bad bench temperature sensor
Bad relay controlling the bench heater
I
Entire relay board is malfunctioning
2
C
bus malfunction
NOTE: Box temperature typically runs ~7 o ambient temperature. c warmer than
Poor/blocked ventilation to the analyzer.
Stopped exhaust-fan
Ambient temperature outside of specified range
Measured concentration value is too high or low.
Concentration slope value to high or too low
Measured concentration value is too high.
Concentration offset value to high.
Failed disk on chip
User erased data
DATA INITIALIZED
Data Storage in DAS was erased
PHOTO TEMP
WARNING
REAR BOARD NOT
DET
RELAY BOARD
WARN
SAMPLE FLOW
WARN
SAMPLE PRES
WARN
PHT DRIVE is
>4800 mVDC
Motherboard not detected on power up.
The CPU cannot communicate with the Relay Board.
Sample flow rate is < 500 cc/min or
> 1000 cc/min.
Sample Pressure is <10 in-Hg or
> 35 in-Hg
Normally 29.92 in-Hg at sea level decreasing at 1 in-Hg per 1000 ft of altitude (with no flow – pump disconnected).
Failed disk on chip
User cleared data
Failed IR photo-detector
Failed sync/demod board
IR photo-detector improperly attached to the sample chamber
Bench temp too high.
Warning only appears on serial i/o com port(s)
I
Front panel display will be frozen, blank or will not respond.
Massive failure of mother board
2
C
bus failure
Failed relay board
Loose connectors/wiring
Failed sample pump
Blocked sample inlet/gas line
Dirty particulate filter
Leak downstream of critical flow orifice
Failed flow sensor/circuitry
If sample pressure is < 10 in-hg: o
Blocked particulate filter o
Blocked sample inlet/gas line o
Failed pressure sensor/circuitry
If sample pressure is > 35 in-hg: o
Pressurized sample gas. Install vent o
Blocked vent line on pressurized sample/zero/span gas supply o
Bad pressure sensor/circuitry
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Table 11-1: Warning Messages – Indicated Failures (cont.)
WARNING
MESSAGE
SAMPLE TEMP
WARN
SOURCE
WARNING
WHEEL TEMP
WARNING
FAULT CONDITION
Sample temperature is < 10 o
C or >
100 o
C.
Occurs when CO
2
Ref is <1250 mVDC or >4950 mVDC.
Either of these conditions will result in an invalid M/R ratio.
SYSTEM RESET The computer has rebooted.
The filter wheel temperature is controlled at 68 2 °
C
POSSIBLE CAUSES
Ambient temperature outside of specified range
Failed bench heater
Failed bench temperature sensor
I
Relay controlling the bench heater
Failed relay board
2
C
bus
GFC wheel stopped
Failed sync/demod board
If status LED’s on the sync/demod board ARE flashing the cause is most likely a failed:
IR source
I
Relay board
2
C
bus
IR photo-detector
This message occurs at power on. If you have not cycled the power on your instrument: o
Failed +5 VDC power, o
Fatal error caused software to restart o
Loose connector/wiring
Blocked cooling vents below GFC Assembly. Make sure that adequate clear space beneath the analyzer.
Analyzer’s top cover removed
Wheel heater
Wheel temperature sensor
Relay controlling the wheel heater
Entire relay board
I
2
C bus
10.1.2. Fault Diagnosis with TEST Functions
Besides being useful as predictive diagnostic tools, the test functions viewable from the front panel can be used to isolate and identify many operational problems when combined with a thorough understanding of the analyzer’s theory of operation (see Section 10).
The acceptable ranges for these test functions are listed in the “Nominal Range” column of the analyzer
Final Test and Validation Data Sheet (p/n 04307) shipped with the instrument. Values outside these acceptable ranges indicate a failure of one or more of the analyzer’s subsystems. Functions whose values are still within the acceptable range but have significantly changed from the measurement recorded on the factory data sheet may also indicate a failure. A worksheet has been provided in
Appendix C to assist in recording the value of these test functions.
Table 11-2 contains some of the more common causes for these values to be out of range.
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Table 10-2: Test Functions - Indicated Failures
TEST
FUNCTIONS
TIME
RANGE
STABIL
CO2 MEAS
&
CO2 REF
MR RATIO
PRES
SAMPLE FL
SAMPLE
TEMP
BENCH TEMP
WHEEL TEMP
BOX TEMP
PHT DRIVE
INDICATED FAILURE(S)
Time of day clock is too fast or slow: To adjust See Section 6.6.
Battery in clock chip on CPU board may be dead.
Incorrectly configured measurement range(s) could cause response problems with a Data logger or chart recorder attached to one of the analog output.
If the Range selected is too small, the recording device will over range.
If the Range is too big, the device will show minimal or no apparent change in readings.
Indicates noise level of instrument or CO
2
concentration of sample gas (See Section 10.4.2 for causes).
If the value displayed is too high the IR Source has become brighter. Adjust the variable gain potentiometer on the sync/demod board
If the value displayed is too low or constantly changing and the CO o
Failed multiplexer on the mother board
2
REF
is OK: o
Failed sync/demod board o
Loose connector or wiring on sync/demod board
Flow of purge gas to the GFC wheel housing may have stopped
If the value displayed is too low or constantly changing and the CO
2
REF
is BAD: o
GFC wheel stopped or rotation is too slow o
Failed sync/demod board IR source o
Failed IR source o
Failed relay board o
Failed
I
2
C
bus o
Failed IR photo-detector
When the analyzer is sampling zero air and the ratio is too low: o
The reference cell of the GFC wheel is contaminated or leaking. o
The alignment between the GFC wheel and the segment sensor, the M/R sensor or both is incorrect. o
Failed sync/demod board o
Flow of purge gas to the GFC wheel housing may have stopped
When the analyzer is sampling zero air and the ratio is too high: o
Zero air is contaminated o
Failed IR photo-detector
See Table 11-1 for SAMPLE PRES WARN
Check for gas flow problems. see Section 11.1.6
SAMPLE TEMP should be close to BENCH TEMP. Temperatures outside of the specified range or oscillating temperatures are cause for concern
Bench temp control improves instrument noise, stability and drift. Temperatures outside of the specified range or oscillating temperatures are cause for concern. See Table 11-1 for BENCH TEMP WARNING
Wheel temp control improves instrument noise, stability and drift. Outside of set point or oscillating temperatures are cause for concern. See Table 11-1 for WHEEL TEMP WARNING
If the box temperature is out of range, check fan in the power supply module. Areas to the side and rear of instrument should allow adequate ventilation. See Table 11-1 for BOX TEMP WARNING.
If this drive voltage is out of range it may indicate one of several problems:
- A poor mechanical connection between the various components in inside the detector housing
- An electronic failure of the IR Photo-Detector’s built-in cooling circuitry, or;
- A temperature problem inside the analyzer chassis. In this case other temperature warnings would also be active such as BENCH TEMP WARNING or BOX TEMP WARNING.
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TEST
FUNCTIONS
SLOPE
OFFSET
INDICATED FAILURE(S)
Values outside range indicate
Contamination of the zero air or span gas supply
Instrument is miss-calibrated
Blocked gas flow
Contaminated or leaking GFC wheel (either chamber)
Faulty IR photo-detector
Faulty sample faulty IR photo-detector pressure sensor (P1) or circuitry
Invalid M/R ratio (see above)
Bad/incorrect span gas concentration due.
Values outside range indicate
Contamination of the zero air supply
Contaminated or leaking GFC wheel (either chamber)
Faulty IR photo-detector
10.1.3. Using the Diagnostic Signal I/O Function
The Signal I/O parameters found under the DIAG Menu (See Section 6.9.2 and Appendix A) combined with a thorough understanding of the instrument’s Theory of Operation (found in Section 10) are useful for troubleshooting in three ways:
The technician can view the raw, unprocessed signal level of the analyzer’s critical inputs and outputs.
All of the components and functions that are normally under algorithmic control of the CPU can be manually exercised.
The technician can directly control the signal level of the Analog and Digital Output signals.
This allows the technician to systematically observe the effect of directly controlling these signals on the operation of the analyzer. Below in Figure 11-2 is an example of how to use the signal I/O menu to view the raw voltage of an input signal or to control the state of an output voltage or control signal. The specific parameter will vary depending on the situation.
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SAMPLE* RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG EXIT
SAMPLE ENTER SETUP PASS : 818
8 1 8 ENTR EXIT
DIAG SIGNAL I/O
PREV NEXT ENTR EXIT
DIAG I/O 0 ) EXT_ZERO_CAL=ON
PREV NEXT JUMP PRNT EXIT
If parameter is an input signal
If parameter is an output signal or control
DIAG I/O 28) SAMPLE_PRESSURE=2540 MV
PREV NEXT JUMP PRNT EXIT
DIAG I/O 22
PREV NEXT JUMP
) WHEEL_HTR= ON
ON PRNT EXIT
Toggles parameter
ON/OFF
DIAG I/O 22
PREV NEXT JUMP
) WHEEL_HTR= OFF
OFF PRNT EXIT
Exit returns to
DIAG display & all values return to software control
Figure 10-2: Example of Signal I/O Function
10.1.4. Internal Electronic Status LEDs
Several LED’s are located inside the instrument to assist in determining if the analyzer’s CPU, I 2 and relay board, GFC wheel and the sync/demodulator board are functioning properly.
C bus
10.1.4.1. CPU Status Indicator
DS5, a red LED, that is located on upper portion of the motherboard, just to the right of the CPU board, flashes when the CPU is running the main program loop. After power-up, approximately 30 to 60
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer seconds, DS5 should flash on and off. If characters are written to the front panel display but DS5 does not flash then the program files have become corrupted. If after 30 – 60 seconds neither the DS5 is flashing or no characters have been written to the front panel display then the CPU is bad and must be replaced.
Motherboard
CPU Status LED
Figure 10-3: CPU Status Indicator
10.1.4.2. Sync Demodulator Status LED’s
Two LEDs located on the Sync/Demod Board and are there to make it obvious that the GFC Wheel is spinning and the synchronization signals are present:
Table 10-3: Sync/Demod Board Status Failure Indications
LED FAULT STATUS
D1
D2
FUNCTION
M/R Sensor Status
(Flashes slowly)
Segment Sensor
Status
(Flashes quickly)
LED is stuck
ON or OFF
LED is stuck
ON or OFF
INDICATED FAILURE(S)
GFC Wheel is not turning
M/R Sensor on Opto-Pickup Board failed
Sync/Demod Board failed
JP 4 Connector/Wiring faulty
Failed/Faulty +5 VDC Power Supply (PS1)
GFC Wheel is not turning
Segment Sensor on Opto-Pickup Board failed
Sync/Demod Board failed
JP 4 Connector/Wiring faulty
Failed/Faulty +5 VDC Power Supply (PS1)
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Troubleshooting
JP4 Connector to Opto-Pickup
Board
Model GFC7000TA Carbon Dioxide Analyzer
D1 – M/R Sensor Status
D2 – Segment Sensor Status
Figure 10-4: Sync/Demod Board Status LED Locations
10.1.4.3. Relay Board Status LEDs
There are eight LEDs located on the Relay Board. The most important of which is D1 is the most important LED, which indicates the health of the I
2
C bus. If D1 is blinking the other faults following LEDs can be used in conjunction with DIAG menu signal I/O to identify hardware failures of the relays and switches on the relay (See Section 6.9.2 and Appendix D).
Table 10-4: I2C Status LED Failure Indications
LED
D1
(Red)
FUNCTION
I 2 C bus Health
(Watchdog
Circuit)
FAULT STATUS
Continuously ON or
Continuously OFF
INDICATED FAILURE(S)
Failed/Halted CPU
Faulty Motherboard, or Relay Board
Faulty Connectors/Wiring to/from Relay Board
Failed/Faulty +5 VDC Power Supply (PS1)
STATUS LED’s
DC VOLTAGE TEST
POINTS
RELAY PCA
Figure 10-5: Relay Board Status LEDs
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Table 10-5: Relay Board Status LED Failure Indications
SIGNAL I/O PARAMETER
LED FUNCTION
ACTIVATED BY VIEW RESULT
D2
Yellow
D3
Yellow
WHEEL
HEATER
BENCH
HEATER
DIAGNOSTIC TECHNIQUE
Voltage displayed should change. If not:
Failed Heater
WHEEL_HEATER WHEEL_TEMP Faulty Temperature Sensor
Failed AC Relay
Faulty Connectors/Wiring
Voltage displayed should change. If not:
BENCH_HEATER BENCH_TEMP
Failed Heater
Faulty Temperature Sensor
Failed AC Relay
Faulty Connectors/Wiring
D4
Yellow
SPARE
D5
Green
D6
Green
SAMPLE/CAL
GAS VALVE
OPTION
ZERO/SPAN
GAS VALVE
OPTION
Sample/Cal Valve should audibly change states. If not:
Failed Valve
Failed Relay Drive IC on Relay Board
Failed Relay Board
Faulty +12 VDC Supply (PS2)
Faulty Connectors/Wiring
Zero/Span Valve should audibly change states. If not:
Failed Valve
D7
Green
D8
Green
SHUTOFF
VALVE OPTION
IR SOURCE
Failed Relay Board
Faulty +12 VDC Supply (PS2)
Faulty Connectors/Wiring
Shutoff Valve should audibly change states. If not:
SHUTOFF_VALVE N/A
Failed Valve
Failed Relay Drive IC on Relay Board
Failed Relay Board
Faulty +12 VDC Supply (PS2)
IR_SOURCE CO
2
_MEASURE
Faulty Connectors/Wiring
Voltage displayed should change. If not:
Failed IR Source
Faulty +12 VDC Supply (PS2)
Failed Relay Board
Failed IR Photo-Detector
Failed Sync/Demod Board
Faulty Connectors/Wiring
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
10.2. Gas Flow Problems
The GFC 7000TA has two main gas flow path, the sample gas flow path and the GFC purge gas flow path. Both are controlled by a critical flow orifice. Only the sample gas path is measured and reported.
When the IZS or zero/span valve options are installed, there are several subsidiary paths but none of those are displayed on the front panel or stored by the DAS.
With the O
2
sensor option installed, third gas flow controlled with a critical flow orifice is added, but this flow is not measured or reported.
In general, flow problems can be divided into three categories:
Flow is too high
Flow is greater than zero, but is too low, and/or unstable
Flow is zero (no flow)
When troubleshooting flow problems, it is crucial to confirm the actual flow rate without relying on the analyzer’s flow display. The use of an independent, external flow meter to perform a flow check as described in Section 9.3.4 is essential. If this test shows the flow to be correct, check the pressure sensors as described in Section 11.5.6.5.
The flow diagrams provided in this manual depicting the GFC 7000TA in its standard configuration and with options installed can help in trouble-shooting flow problems. For your convenience they are collected here.
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10.2.1. GFC 7000TA Internal Gas Flow Diagrams
Figure 10-6: GFC 7000TA – Basic Internal Gas Flow
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Troubleshooting
SAMPLE GAS
INLET
PRESSURE
SPAN INLET
VENT SPAN
OUTLET
IZS INLET
EXHAUST
GAS OUTLET
Shutoff
Valve
Model GFC7000TA Carbon Dioxide Analyzer
Sample / Cal
Valve
Zero / Span
Valve
PUMP
Sample Gas
Flow Control
Flow / Pressure
Sensor PCA
CO
2
FLOW
SENSOR
SAMPLE
PRESSURE
SENSOR
PURGE GAS
INLET
Purge Gas
Pressure Control
Figure 10-7: Internal Pneumatic Flow – Ambient Zero/Pressurized Span Valves
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Troubleshooting
SAMPLE GAS
INLET
PRESSURE
SPAN INLET
VENT SPAN
OUTLET
Model GFC7000TA Carbon Dioxide Analyzer
Sample / Cal
Valve
Zero / Span
Valve
IZS INLET
EXHAUST
GAS OUTLET
PUMP
Sample Gas
Flow Control
Flow / Pressure
Sensor PCA
NO
2
FLOW
SENSOR
SAMPLE
PRESSURE
SENSOR
PURGE GAS
INLET
Purge Gas
Pressure Control
Figure 10-8: Internal Pneumatic Flow – Ambient Zero/Ambient Span
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
Figure 10-9: GFC 7000TA – Internal Pneumatics with O
2
Sensor Option 65A
10.2.2. Typical Sample Gas Flow Problems
10.2.2.1. Flow is Zero
The unit displays a SAMPLE FLOW warning message on the front panel display or the SAMPLE FLOW test function reports a zero or very low flow rate.
Confirm that the sample pump is operating (turning). If not, use an AC voltmeter to make sure that power is being supplied to the pump. If no power is present at the electrical leads of the pump.
1. If AC power is being supplied to the pump, but it is not turning, replace the pump.
2. If the pump is operating but the unit reports no gas flow, perform a flow check as described in
Section 9.3.4.
3. If no independent flow meter is available:
Disconnect the gas lines from both the sample inlet and the exhaust outlet on the rear panel of the instrument.
Make sure that the unit is in basic SAMPLE Mode.
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Place a finger over an Exhaust outlet on the rear panel of the instrument.
If gas is flowing through the analyzer, you will feel pulses of air being expelled from the
Exhaust outlet.
4. If gas flows through the instrument when it is disconnected from its sources of zero air, span gas or sample gas, the flow problem is most likely not internal to the analyzer. Check to make sure that:
All calibrators/generators are turned on and working correctly.
Gas bottles are not empty or low.
Valves, regulators and gas lines are not clogged or dirty.
10.2.2.2. Low Flow
1. Check if the pump diaphragm is in good condition. If not, rebuild the pump (See Section 9.3.2).
Check the Spare Parts List for information of pump rebuild kits.
2. Check for leaks as described in Section 9.3.3. Repair the leaking fitting, line or valve and recheck.
3. Check for the sample filter and the orifice filter for dirt. Replace filters (See Sections 9.3.1 and
11.5.1 respectively).
4. Check for partially plugged pneumatic lines, orifices, or valves. Clean or replace them.
5. If an IZS option is installed in the instrument, press CALZ and CALS. If the flow increases then suspect a bad sample/cal valve.
10.2.2.3. High Flow
The most common cause of high flow is a leak in the sample flow control assembly or between there and the pump. If no leaks or loose connections are found in the fittings or the gas line between the orifice and the pump, rebuild/clean the sample flow control assembly as described in Section 11.6.1.
10.2.2.4. Displayed Flow = “XXXX”
This warning means that there is inadequate gas flow. There are four conditions that might cause this:
1. A leak upstream or downstream of the flow sensor
2. A flow obstruction upstream or downstream of the flow sensor
3. Bad Flow Sensor Board
To determine which case it is, view the sample pressure and sample flow functions via the front panel. If the sample pressure is reading abnormally low, then the cause is likely a flow obstruction upstream of the flow sensor. First, check the sample filter and make sure it is not plugged and then systematically check all the other components upstream of the orifice to ensure that they are not obstructed.
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If the sample pressure is reading normal but the sample flow is reading low then it is likely that the pump diaphragm is worn or there is an obstruction downstream of the flow sensor.
10.2.2.5. Actual Flow Does Not Match Displayed Flow
If the actual flow measured does not match the displayed flow, but is within the limits of 720-880 cc/min, adjust the calibration of the flow measurement as described in Section 6.9.8.
10.2.2.6. Sample Pump
The sample pump should start immediately after the front panel power switch is turned ON. With the
Sample Inlet plugged, the test function PRES should read about 10”-Hg for a pump in good condition.
Readings above 10” Hg indicate that the pump needs rebuilding. If the test function SAMP FL is greater than 10 cm 3 /min there is a leak in the pneumatic lines.
10.2.3. Poor or Stopped Flow of Purge Gas
If sufficient purge gas is not supplied to the GFC wheel housing, cyclical fluctuations in readings at zero or low CO
2
concentrations, such as < 100 ppm, may occur. These fluctuations are the result of changes in the CO
2
concentration of the ambient atmosphere throughout the course of the day and night. In isolated areas with relatively few people working nearby the ambient CO concentration will fall during the
2 day and rise during the night as rate of photosynthesis of the plants in the surrounding area decreases and increases. In a lab environment with a relatively high human occupancy the ambient CO
2 concentration will increase during those parts of the day when the highest number of workers are present.
If the GFC wheel housing is allowed to fill with ambient air, these natural, diurnal fluctuations might be detected by the instrument and cause it’s in its calculation of the CO drift.
2
concentration of the sample gas to
Another possible symptom of poor or stopped purge gas flow would be the inability to measure zero concentrations accurately at the end of a work day on a system that was calibrated at the beginning of a workday. Although this could also be due to local fluctuations in ambient CO day.
2
concentration during the
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Troubleshooting
10.3. Calibration Problems
Model GFC7000TA Carbon Dioxide Analyzer
10.3.1. Miscalibrated
There are several symptoms that can be caused by the analyzer being miss-calibrated. This condition is indicated by out of range Slopes and Offsets as displayed through the test functions and is frequently caused by the following:
1. BAD SPAN GAS. This can cause a large error in the slope and a small error in the offset.
Delivered from the factory, the GFC 7000TA’s slope is within ±15% of nominal. Bad span gas will cause the analyzer to be calibrated to the wrong value. If in doubt have the span gas checked by and independent lab.
2. CONTAMINATED ZERO GAS. Excess H
2 indirectly affect the slope.
O can cause a positive or negative offset and will
3. Dilution calibrator not set up correctly or is malfunctioning. This will also cause the slope, but not the zero, to be incorrect. Again the analyzer is being calibrated to the wrong value.
4. Too many analyzers on the manifold. This can cause either a slope or offset error because ambient gas with its pollutants will dilute the zero or span gas.
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
10.3.2. Non-Repeatable Zero and Span
As stated earlier, leaks both in the GFC 7000TA and in the external system are a common source of unstable and non-repeatable readings.
1. Check for leaks in the pneumatic systems as described in Section 9.3.3. Don’t forget to consider pneumatic components in the gas delivery system outside the GFC 7000TA. Such as:
A change in zero air source such as ambient air leaking into zero air line, or;
A change in the span gas concentration due to zero air or ambient air leaking into the span gas line.
2. Once the instrument passes a leak check, do a flow check (See Section 9.3.4) to make sure adequate sample is being delivered to the sensor assembly.
3. A failing IR photo-detector may be at fault. Check the CO2 MEAS and CO2 REF test functions via the front panel display to make sure the signal levels are in the normal range (See Appendix
A) and are quiet.
4. Confirm the sample pressure, wheel temperature, bench temperature, and sample flow readings are correct and have steady readings.
5. Disconnect the exhaust line from the optical bench near the rear of the instrument and plug this line into the SAMPLE inlet creating a pneumatic loop. The CO
2
concentration (either zero or span) now must be constant. If readings become quiet, the problem is in the external pneumatics supplies for sample gas, span gas or zero air.
6. If pressurized span gas is being used with a zero/span valve option, make sure that the venting is adequate (See Section 3.1.2 and 5.4)
7. If it is the zero point that is non-repeatable, and if that non-repeatability seems to only occur at a certain time of day, such as when worker occupancy is highest or lowest, make sure the flow of purge gas to the GFC wheel housing has not stopped (See Sections 10.2.2 and 11.1.7 for more information).
10.3.3. Inability to Span – Touchscreen SPAN Button Not Visible
1. Confirm that the carbon dioxide span gas source is accurate; this can be done by switching between two span-gas tanks. If the CO the tanks.
2
concentration is different, there is a problem with one of
2. Check for leaks in the pneumatic systems as described in Section 9.3.3.
3. Make sure that the expected span gas concentration entered into the instrument during calibration is the correct span gas concentration and not too different from expected span value.
This can be viewed via the RNG Menu (See Section 6.7).
4. Check to make sure that there is no ambient air or zero air leaking into span gas line.
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Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
10.3.4. Inability to Zero – Touchscreen ZERO Button Not Visible
1. Confirm that there is a good source of zero air. Dilute a tank of span gas with the same amount of zero air from two different sources. If the CO
2
Concentration of the two measurements is different, there is a problem with one of the sources of zero air.
2. Check for leaks in the pneumatic systems as described in Section 9.3.3.
3. If the analyzer has had zero/span valve options 52 or 53, the CO
2 maintenance.
scrubber may need
4. Check to make sure that there is no ambient air leaking into zero air line.
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10.4. Other Performance Problems
Dynamic problems (i.e. problems which only manifest themselves when the analyzer is monitoring sample gas) can be the most difficult and time consuming to isolate and resolve. The following provides an itemized list of the most common dynamic problems with recommended troubleshooting checks and corrective actions.
10.4.1. Temperature Problems
Individual control loops are used to maintain the set point of the absorption bench, filter wheel, and IR photo-detector temperatures. If any of these temperatures are out of range or are poorly controlled, the
GFC 7000TA will perform poorly.
10.4.1.1. Box or Sample Temperature
Box Temperature
The box temperature sensor is mounted to the motherboard and cannot be disconnected to check its resistance. Rather check the BOX TEMP signal using the SIGNAL I/O function under the DIAG Menu
(See Section 10.1.3). This parameter will vary with ambient temperature, but at ~30 temperature) the signal should be ~1450 mV. o
C (6-7° above room
Sample Temperature
The Sample Temperature should closely track the bench temperature. If it does not, locate the sensor, which is located at the midpoint of the optical bench in a brass fitting. Unplug the connector labeled
“Sample”, and measure the resistance of the thermistor; at room temperature (25°C) it should be ~30K
Ohms, at operating temperature, 48°C, it should be ~ 12K Ohms
10.4.1.2. Bench Temperature
There are three possible failures that could cause the Bench temperature to be incorrect.
1. The heater mounted to the bottom of the Absorption bench is electrically shorted or open. Check the resistance of the two heater elements by measuring between pin 2 and 4 (~76 Ohms), and pin 3 and 4 (~330 Ohms), of the white five-pin connector just below the sample temperature sensor on the Bench (pin 1 is the pointed end).
2. Assuming that the I
2
C bus is working and that there is no other failure with the relay board, the solid-state relay (K2) on the relay board may have failed. Using the BENCH_HEATER parameter under the signal I/O function, as described above, turn on and off K2 (D3 on the relay board should illuminate as the heater is turned on). Check the AC voltage present between pin 2 and 4, for a 100 or 115 VAC model, and pins 3 and 4, for a 220-240 VAC model.
WARNING:
HAZARDOUS VOLTAGES ARE PRESENT DURING THIS TEST
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3. If the relay has failed there should be no change in the voltage across pins 2 and 4 or 3 and 4.
NOTE: K2 is in a socket for easy replacement.
4. If K2 checks out OK, the thermistor temperature sensor located on the optical bench near the front of the instrument could be at fault. Unplug the connector labeled “Bench”, and measure the resistance of the thermistor. At room temperature it should have approximately 30K Ohms resistance near the 48 o C set point it should have ~12K ohms.
10.4.1.3. GFC Wheel Temperature
Like the bench heater above there are three possible causes for the GFC wheel temperature to have failed.
1. The wheel heater has failed. Check the resistance between pins 1 and 4 on the white five-pin connector just below the sample temperature sensor on the bench (pin 1 is the pointed end). It should be approximately 275 ohms.
2. Assuming that the I
2
C bus is working and that there is no other failure with the relay board, the solid-state relay (K1) on the relay board may have failed. Using the WHEEL_HEATER parameter under the signal I/O function, as described above, turn on and off K1 (D2 on the relay board should illuminate as the heater is turned on). Check the AC voltage present between Pin 1 and Pin 4.
WARNING:
HAZARDOUS VOLTAGES ARE PRESENT DURING THIS TEST
3. If the relay has failed there should be no change in the voltage across pins 1 and 4. NOTE: K1 is socketed for easy replacement.
4. If K1 checks out OK, the thermistor temperature sensor located at the front of the filter wheel assembly may have failed. Unplug the connector labeled “Wheel”, and measure the resistance of the thermistor. The resistance near the 68 o
C set point is ~5.7k ohms.
10.4.1.4. IR Photo-Detector TEC Temperature
If the PHT DRIVE test parameter described above in Table 11-2 is out of range there are two four possible causes of failure.
1. The screws retaining the IR photo detector to the absorption bench have become loose.
Carefully tighten the screws, hand-tight and note whether, after the analyzer has come up to operating temperature, whether the PHT DRIVE voltage has returned to an acceptable level.
2. The two large transistor-type devices mounted to the side of the Absorption Bench have come loose from the bench. Tighten the retaining screws and note whether there is an improvement in the PHT DRIVE voltage.
3. The photo-detector has failed. Contact the factory for instructions.
4. The sync demodulator circuit board has failed. Contact the factor for instructions.
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10.4.2. Excessive Noise
Noise is continuously monitored in the TEST functions as the STABIL reading and only becomes meaningful after sampling a constant gas concentration for at least 10 minutes. Compare the current
STABIL reading with that recorded at the time of manufacture (included in the GFC 7000TA Final Test and Validation Data Sheet -p/n 04271 shipped with the unit from Teledyne Instruments).
1. The most common cause of excessive noise is leaks. Leak check and flow check the instrument described in Section 9.3.
2. Detector failure – caused by failure of the hermetic seal or over-temperature due to poor heat sinking of the detector can to the optical bench. In addition to increased noise due to poor signalto-noise ratio, another indicator of detector failure is a drop in the signal levels of the CO
2
MEASURE signal and CO
2
REFERENCE signal.
3. Sync/Demod Board failure. There are many delicate, high impedance parts on this board. Check the CO2 MEAS and CO2 REF Test Functions via the Front Panel Display.
4. The detector cooler control circuit can fail for reasons similar to the detector itself failing.
Symptoms would be a change in MR RATIO Test Function when zero air is being sampled.
Also check the SIGNAL I/O parameter PHT DRIVE. After warm-up, and at 25 o
C ambient, if PHT
DRIVE < 4800 mV, the cooler is working properly. If PHT DRIVE is > 4800 mV there is a malfunction.
5. The +5 and 15 VDC voltages in the GFC 7000TA are provided by switching power supplies.
Switch mode supplies create DC outputs by switching the input AC waveform at high frequencies.
As the components in the switcher age and degrade, the main problem observed is increased noise on the DC outputs. If a noisy switcher power supply is suspected, attach an oscilloscope to the DC output test points located on the top right hand edge of the Relay board. Look for short period spikes > 100 mV p-p on the DC output.
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10.5. Subsystem Checkout
The preceding s of this manual discussed a variety of methods for identifying possible sources of failures or performance problems within the analyzer. In most cases this included a list of possible causes. This describes how to determine individually determine if a certain component or subsystem is actually the cause of the problem being investigated.
10.5.1. AC Mains Configuration
The analyzer is correctly configured for the AC mains voltage in use if:
1. The Sample Pump is running.
2. The GFC wheel motor is spinning. LED’s D1 & D2 (located on the synch/demod PCA) should be flashing.
3. If incorrect power is suspected, check that the correct voltage and frequency is present at the line input on the rear panel.
If the unit is set for 230 VAC and is plugged into 115VAC, or 100VAC the sample pump will not start, and the heaters will not come up to temperature.
If the unit is set for 115 or 100 VAC and is plugged into a 230 VAC circuit, the circuit breaker built into the ON/OFF Switch on the Front Panel will trip to the OFF position immediately after power is switched on.
10.5.2. DC Power Supply
If you have determined that the analyzer’s AC mains power is working, but the unit is still not operating properly, there may be a problem with one of the instrument’s switching power supplies. The supplies can have two faults, namely no DC output, and noisy output.
To assist tracing DC Power Supply problems, the wiring used to connect the various printed circuit assemblies and DC Powered components and the associated test points on the relay board follow a standard color-coding scheme as defined in the following table.
Table 10-6: DC Power Test Point and Wiring Color Codes
NAME
Dgnd
+5V
Agnd
+15V
-15V
+12R
+12V
TEST POINT#
1
2
3
4
5
6
7
TP AND WIRE COLOR
Black
Red
Green
Blue
Yellow
Purple
Orange
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A voltmeter should be used to verify that the DC voltages are correct per the values in the table below, and an oscilloscope, in AC mode, with band limiting turned on, can be used to evaluate if the supplies are producing excessive noise (> 100 mV p-p).
Table 10-7: DC Power Supply Acceptable Levels
POWER
SUPPLY
ASSY
VOLTAG
E
CHECK RELAY BOARD TEST POINTS
FROM TEST POINT TO TEST POINT MIN V
NAME # NAME #
MAX V
PS1 +15 Agnd 3 +15 4 13.5 16V
PS1 -15 Agnd 3 -15V 5 -14V -16V
PS1 Agnd Agnd 3 Dgnd 1 -0.05 0.05
PS1 Chassis Dgnd 1 Chassis N/A -0.05 0.05
10.5.3. I
2
C Bus
Operation of the I
2
C bus can be verified by observing the behavior of D1 on the Relay PCA & D2 on the
Valve Driver PCA . Assuming that the DC power supplies are operating properly, the I
2
C bus is operating properly if: D1 on the relay PCA and D2 of the Valve Driver PCA are flashing
There is a problem with the I
2
C bus if both D1 on the relay PCA and D2 of the Valve Driver PCA are
ON/OFF constantly (steady lit or steady off)
10.5.4. Touchscreen Interface
Verify the functioning of the touchscreen by observing the display when pressing a touchscreen control button. Assuming that there are no wiring problems and that the DC power supplies are operating properly, if pressing a control button on the display does not change the display, any of the following may be the problem:
The touchscreen controller may be malfunctioning.
The internal USB bus may be malfunctioning.
You can verify this failure by logging on to the instrument using APICOM or a terminal program to any of the communications ports. If the analyzer responds to remote commands and the display changes accordingly, the touchscreen interface may be faulty.
10.5.5. LCD Display Module
Verify the functioning of the front panel display by observing it when power is applied to the instrument.
Assuming that there are no wiring problems and that the DC power supplies are operating properly, the display screen should light and show the splash screen with logo and other indications of its state as the
CPU goes through its initialization process.
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10.5.6. Relay Board
The relay board PCA (04135) can be most easily checked by observing the condition of the its status
LEDs on the relay board, as described in Section 10.1.4.3, and the associated output when toggled on and off through signal I/O function in the diagnostic menu, See Section 10.1.3.
1. If the front panel display responds to button presses and D1 on the relay board is not flashing, then either the I 2 C connection between the motherboard and the relay board is bad, or the relay board itself is bad.
2. If D1 on the relay board is flashing and the status indicator for the output in question (heater power, valve drive, etc.) toggles properly using the signal I/O function, then the associated control device on the relay board is bad. Several of the control devices are in sockets and can be easily replaced. The table below lists the control device associated with a particular function:
Table 10-8: Relay Board Control Devices
FUNCTION
Wheel Heater
Bench Heater
Spare AC Control
IZS Valves
IR Source Drive
CONTROL
DEVICE
K1
K2
K3
U4
U5
IN SOCKET
Yes
Yes
Yes
Yes
No
The IR source drive output can be verified by measuring the voltage at J16 with the IR source disconnected. It should be 11.5± 0.5 VDC.
10.5.7. Sensor Assembly
10.5.7.1. Sync/Demodulator Assembly
To verify that the Sync/Demodulator Assembly is working follow the procedure below:
1. Verify that D1 and D2 are flashing (they flash at different rates, see Table 11-3).
If not check the opto pickup assembly, Section 10.5.7.2 and the GFC wheel drive, Section
11.5.6.3.
If the wheel drive and opto pickup are working properly then verify that there is 2.4 ±0.1 VAC and 2.5 ±0.15 VDC between digital ground and TP 5 on the sync demod board. If not then check the wiring between the sync/demod and opto pickup assembly (see interconnect drawing 04216). If good then the sync/demod board is bad.
2. Verify that the IR source is operating, Section 10.5.7.4.
3. With the analyzer connected to zero air, measure between TP11 (measure) and analog ground, and TP12 (reference) and analog ground.
If they are similar to values recorded on the factory data sheet then there is likely a problem with the wiring or the A/D converter.
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If they are not then either the sync demodulator board or the IR-photodetector are bad. See
Section 10.4.1.4 for problems with the IR-photodetector TEC drive.
10.5.7.2. Opto Pickup Assembly
Operation of the opto pickup PCA (04088) can be verified with a voltmeter. Measure the AC and DC voltage between digital ground on the relay board, or touchscreen and TP1 and TP2 on the sync pickup
PCA. For a working board, with the GFC motor spinning, they should read 2.4 ±0.1 VAC and 2.5 ±0.15
VDC.
Further confirmation that the pickups and motor are operating properly can be obtained by measuring the frequency at TP1 and TP2 using a frequency counter, a digital volt meter with a frequency counter, or an oscilloscope per the table below.
Table 10-9: Opto Pickup Board Nominal Output Frequencies
AC MAINS FREQ.
50 Hz
60 Hz
10.5.7.3. GFC Wheel Drive
NOMINAL MEASURED FREQUENCY
TP1
25
30
TP2
300
360
If the D1 and D2 on the sync demodulator board are not flashing then:
1. Check for power to the motor by measuring between pins 1 and 3 on the connector feeding the motor. For instruments configured for 120 or 220-240VAC there should be approximately 88
VAC for instruments configured for 100VAC, it should be the voltage of the AC mains, approximately 100VAC.
2. Verify that the frequency select jumper, JP4, is properly set on the Relay Board. For 50 Hz operation it should be installed. For 60 Hz operation may either be missing or installed in a vertical orientation.
3. If there is power to the motor and the frequency select jumper is properly set then the motor is likely bad. See Section 10.6.2 for instructions on removing and replacing the GFC assembly that the motor is bolted to.
10.5.7.4. IR Source
The IR source can be checked using the following procedure:
1. Disconnect the source and check its resistance when cold. When new, the source should have a cold resistance of more than 1.5 Ohms but less than 3.5 Ohms. If not, then the source is bad.
2. With the source disconnected, energize the analyzer and wait for it to start operating. Measure the drive Voltage between pins 1 and 2 on the jack that the source is normally connected to; it should be 11.5 ± 0.25 VDC. If not, then there is a problem with either the wiring, the Relay
Board, or the +12V power supply.
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3. If the drive voltage is correct in step 2, then remove the source from the heat sink assembly (2 screws on top) and connect to its mating connector. Observe the light being emitted from the source. It should be centered at the bottom of the U-shaped element. If there is either no emission or a badly centered emission then the source is bad.
10.5.7.5. Pressure/Flow Sensor Assembly
The pressure/flow sensor PCA, located on the top of the absorption bench, can be checked with a
Voltmeter using the following procedure which, assumes that the wiring is intact, and that the motherboard and the power supplies are operating properly:
1. For Pressure related problems:
Measure the voltage across C1 it should be 5 ± 0.25 VDC. If not then the board is bad.
Measure the voltage across TP4 and TP1. With the sample pump disabled it should be 4500 mV ±250 mV. With the pump energized it should be approximately 200 mV less. If not, then
S1, the pressure transducer is bad, the board is bad, or there is a pneumatic failure preventing the pressure transducer from sensing the absorption cell pressure properly.
For flow related problems:
Measure the voltage across TP2 and TP1 it should be 10 ±0.25 VDC. If not then the board is bad.
Measure the voltage across TP3 and TP1. With proper flow (800 cc/min at the sample inlet) this should be approximately 4.5V (this voltage will vary with altitude). With flow stopped
(sample inlet blocked) the voltage should be approximately 1V. If the voltage is incorrect, the flow sensor is bad, the board is bad or there is a leak upstream of the sensor.
10.5.8. Motherboard
10.5.8.1. A/D Functions
The simplest method to check the operation of the A-to-D converter on the motherboard is to use the
Signal I/O function under the DIAG menu to check the two A/D reference voltages and input signals that can be easily measured with a voltmeter.
1. Use the Signal I/O function (See Section 10.1.3 and Appendix A) to view the value of
REF_4096_MV and REF_GND. If both are within 3 mV of nominal (4096 and 0), and are stable,
±0.5 mV then the basic A/D is functioning properly. If not then the motherboard is bad.
2. Choose a parameter in the Signal I/O function such as SAMPLE_PRESSURE, SAMPLE_FLOW,
CO
2
_MEASURE or CO
2
_REFERENCE . Compare these voltages at their origin (see interconnect drawing 04215 and interconnect list 04216) with the voltage displayed through the signal I/O function. If the wiring is intact but there is a large difference between the measured and displayed voltage (±10 mV) then the motherboard is bad.
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10.5.8.2. Analog Outputs: Voltage
Model GFC7000TA Carbon Dioxide Analyzer
To verify that the analog outputs are working properly, connect a voltmeter to the output in question and perform an analog output step test as described in Section 6.9.3.
For each of the steps, taking into account any offset that may have been programmed into channel (See
Section 6.9.4), the output should be within 1% of the nominal value listed in the table below except for the
0% step, which should be within 2 to 3 mV. If one or more of the steps fails to be within this range then it is likely that there has been a failure of the either or both of the DACs and their associated circuitry on the motherboard.
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Table 10-10: Analog Output Test Function - Nominal Values Voltage Outputs
FULL SCALE OUTPUT VOLTAGE
STEP %
1 0
NOMINAL OUTPUT VOLTAGE
0 0 0 0
10.5.8.3. Analog Outputs: Current Loop
To verify that the analog outputs with the optional current mode output are working properly, connect a
250 ohm resistor across the outputs and use a voltmeter to measure the output as described in Section
6.9.4.2 and then perform an analog output step test as described in Section 6.9.3.
For each step the output should be within 1% of the nominal value listed in the table below.
Table 10-11: Analog Output Test Function - Nominal Values Current Outputs
OUTPUT RANGE
2 -20 4 -20
NOMINAL OUTPUT VALUES
STEP % CURRENT V(250 OHMS) CURRENT
1 0 2 0.5V 4
V(250 OHMS)
1
2 20 5.6
3 40 9.2
4 60 12.8
5 80 16.4
6 100 20
1.4
2.3 10.4
3.2 13.6
4.1 16.8
5
7.2
20
1.8
2.6
3.4
4.2
5
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10.5.8.4. Status Outputs
The procedure below can be used to test the Status outputs:
1. Connect a jumper between the “D“ pin and the “” pin on the status output connector.
2. Connect a 1000 ohm resistor between the “+” pin and the pin for the status output that is being tested.
3. Connect a voltmeter between the “” pin and the pin of the output being tested (see table below).
Under the DIAG SIGNAL I/O menu (See Section 10.1.3), scroll through the inputs and outputs until you get to the output in question. Alternately turn on and off the output noting the voltage on the voltmeter, it should vary between 0 volts for ON and 5 volts for OFF.
Table 10-12: Status Outputs Check
PIN (LEFT TO RIGHT) STATUS
7 ALRM1
8 ALRM2
10.5.8.5. Control Inputs – Remote Zero, Span
The control input bits can be tested by the following procedure:
1. Connect a jumper from the +5 pin on the Status connector to the x5V on the Control In connector.
2. Connect a second jumper from the ‘-‘ pin on the Status connector to the A pin on the Control In connector. The instrument should switch from SAMPLE mode to ZERO CAL R mode.
3. Connect a second jumper from the ‘-‘ pin on the Status connector to the B pin on the Control In connector. The instrument should switch from SAMPLE mode to SPAN CAL R mode.
4. In each case, the GFC 7000TA should return to SAMPLE mode when the jumper is removed.
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10.5.9. CPU
There are two major types of failures associated with the CPU board: complete failure and a failure associated with the Disk on Module (DOM). If either of these failures occur, contact the factory.
For complete failures, assuming that the power supplies are operating properly and the wiring is intact, the CPU is faulty if on power-on, the watchdog LED on the motherboard is not flashing.
In some rare circumstances, this failure may be caused by a bad IC on the motherboard, specifically U57, the large, 44-pin device on the lower right hand side of the board. If this is true, removing U57 from its socket will allow the instrument to start up but the measurements will be invalid.
If the analyzer stops during initialization (the front panel display shows a fault or warning message), it is likely that the DOM, the firmware or the configuration and data files have been corrupted.
10.5.10. RS-232 Communications
10.5.10.1. General RS-232 Troubleshooting
Teledyne Instruments analyzers use the RS-232 communications protocol to allow the instrument to be connected to a variety of computer-based equipment. RS-232 has been used for many years and as equipment has become more advanced, connections between various types of hardware have become increasingly difficult. Generally, every manufacturer observes the signal and timing requirements of the protocol very carefully.
Problems with RS-232 connections usually center around 4 general areas:
1. Incorrect cabling and connectors. See Section 6.11.2 for connector and pin-out information.
2. The BAUD rate and protocol are incorrectly configured. See Section 6.10.7.
3. If a modem is being used, additional configuration and wiring rules must be observed. See
Section 6.13.2.6
4. Incorrect setting of the DTE – DCE Switch is set correctly. See Section 6.10.5
5. Verify that cable (03596) that connects the serial COM ports of the CPU to J12 of the motherboard is properly seated
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10.5.10.2. Troubleshooting Analyzer/Modem or Terminal Operation
These are the general steps for troubleshooting problems with a modem connected to a Teledyne
Instruments analyzer.
1. Check cables for proper connection to the modem, terminal or computer.
2. Check to make sure the DTE-DCE is in the correct position as described in Section 6.10.5.
3. Check to make sure the set up command is correct (See Section 6.13.2.7)
4. Verify that the Ready to Send (RTS) signal is at logic high. The GFC 7000TA sets pin 7 (RTS) to greater than 3 volts to enable modem transmission.
5. Make sure the BAUD rate, word length, and stop bit settings between modem and analyzer match, See Section 6.10.7.
6. Use the RS-232 test function to send “w” characters to the modem, terminal or computer; See
Section 6.10.8.
7. Get your terminal, modem or computer to transmit data to the analyzer (holding down the space bar is one way); the green LED should flicker as the instrument is receiving data.
8. Make sure that the communications software or terminal emulation software is functioning properly.
Further help with serial communications is available in a separate manual “RS-232 Programming Notes”
Teledyne Instruments part number 013500000.
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10.6. Repair Procedures
This contains procedures that might need to be performed on rare occasions when a major component of the analyzer requires repair or replacement.
10.6.1. Repairing Sample Flow Control Assembly
The critical flow orifice is housed in the flow control assembly (Teledyne Instruments part number:
001760400) located on the top of the optical bench. A sintered filter protects the jewel orifice so it is unusual for the orifice to need replacing, but if it does, or the filter needs replacement please use the following procedure (see the Spare Parts list in Appendix B for part numbers and kits):
1. Turn off power to the analyzer.
2. Locate the assembly attached to the sample pump, see Figure 3–3.
3. Disconnect the pneumatic connection from the flow assembly and the assembly from the pump.
4. Remove the fitting and the components as shown in the exploded view in Figure 11.6.
5. Replace the o-rings (p/n OR000001) and the sintered filter (p/n FL000001).
6. If replacing the critical flow orifice itself (P/N 00094100), make sure that the side with the colored window (usually red) is facing upstream to the flow gas flow.
7. Apply new Teflon
®
tape to the male connector threads
8. Re-assemble in reverse order.
9. After reconnecting the power and pneumatic lines, flow check the instrument as described in
Section 9.3.4.
Pneumatic Connector, Male 1/8”
(P/N FT_70
O-Ring
(P/N OR_01)
Spring
(P/N HW_20)
Sintered Filter
(P/N FL_01)
Critical Flow Orifice
(P/N 00094100)
Make sure it is placed with the
jewel down)
Purge Housing
(P/N 000850000)
Figure 10-10: Critical Flow Restrictor Assembly Disassembly
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10.6.2. Removing/Replacing the GFC Wheel
When removing or replacing the GFC Wheel it is important to perform the disassembly in the following order to avoid damaging the components:
1. Turn off the analyzer.
2. Remove the top cover as described in “Getting Started” Section 3.1.
3. Open the instrument’s hinged front panel.
4. Locate the GFC wheel/motor assembly (see Figure 3-3).
5. Unplug the following electronic components:
The GFC wheel housing temperature sensor;
GFC wheel motor power supply
6. Unscrew the purge gas line hex nut and remove the 1/8 inch FEP purge gas line.
10
7
8
9
Figure 10-11: Opening the GFC Wheel Housing
7. Remove the two (2) screws holding the opto-pickup printed circuit assembly to the GFC wheel housing.
8. Carefully remove the opto-pickup printed circuit assembly.
9. Remove the four (4) screws holding the GFC wheel motor/heat sink assembly to the GFC wheel housing.
10. Carefully remove the GFC wheel motor/heat sink assembly from the GFC wheel housing.
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11. Remove the one (1) screw fastening the GFC wheel/mask assembly to the GFC motor hub.
11
12
Figure 10-12: Removing the GFC Wheel
12. Remove the GFC wheel/mask assembly.
13. Follow the previous steps in reverse order to put the GFC wheel/motor assembly back together.
10.6.3. Disk-On-Module Replacement Procedure
NOTE
Servicing of circuit components requires electrostatic discharge protection, i.e. ESD grounding straps, mats and containers. Failure to use ESD protection when working with electronic assemblies will void the instrument warranty. Refer to Section 11 for more information on preventing ESD damage.
Replacing the Disk-on-Module (DOM) will cause loss of all DAS data; it may also cause loss of some instrument configuration parameters unless the replacement DOM carries the exact same firmware version. Whenever changing the version of installed software, the memory must be reset. Failure to ensure that memory is reset can cause the analyzer to malfunction, and invalidate measurements. After the memory is reset, the A/D converter must be re-calibrated, and all information collected in Step 1 below must be re-entered before the instrument will function correctly. Also, zero and span calibration should be performed.
1. Document all analyzer parameters that may have been changed, such as range, auto-cal, analog output, serial port and other settings before replacing the DOM.
2. Turn off power to the instrument, fold down the rear panel by loosening the mounting screws.
3. When looking at the electronic circuits from the back of the analyzer, locate the Disk-on-Module in the right-most socket of the CPU board.
4. The DOM should carry a label with firmware revision, date and initials of the programmer.
5. Remove the nylon standoff clip that mounts the DOM over the CPU board, and lift the DOM off the CPU. Do not bend the connector pins.
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6. Install the new Disk-on-Module, making sure the notch at the end of the chip matches the notch in the socket.
7. It may be necessary to straighten the pins somewhat to fit them into the socket. Press the chip all the way in.
8. Close the rear panel and turn on power to the machine.
9. If the replacement DOM carries a firmware revision, re-enter all of the setup information.
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ESD Model GFC7000TA Carbon Dioxide Analyzer
11. A PRIMER ON ELECTRO-STATIC DISCHARGE
Teledyne Instruments considers the prevention of damage caused by the discharge of static electricity to be extremely important part of making sure that your analyzer continues to provide reliable service for a long time. This section describes how static electricity occurs, why it is so dangerous to electronic components and assemblies as well as how to prevent that damage from occurring.
11.1. How Static Charges are Created
Modern electronic devices such as the types used in the various electronic assemblies of your analyzer, are very small, require very little power and operate very quickly. Unfortunately, the same characteristics that allow them to do these things also make them very susceptible to damage from the discharge of static electricity. Controlling electrostatic discharge begins with understanding how electro-static charges occur in the first place.
Static electricity is the result of something called triboelectric charging which happens whenever the atoms of the surface layers of two materials rub against each other. As the atoms of the two surfaces move together and separate, some electrons from one surface are retained by the other.
Materials
Makes
Contact
Materials
Separate
+ + + +
P
ROTONS
= 3
E
LECTRONS
= 3
N ET C HARGE = 0
P
ROTONS
= 3
E
LECTRONS
= 3
N ET C HARGE = 0
P
ROTONS
= 3
E LECTRONS = 2
N ET C HARGE = -1
P ROTONS = 3
E LECTRONS = 4
N
ET
C
HARGE
= +1
Figure 11-1: Triboelectric Charging
If one of the surfaces is a poor conductor or even a good conductor that is not grounded, the resulting positive or negative charge cannot bleed off and becomes trapped in place, or static. The most common example of triboelectric charging happens when someone wearing leather or rubber soled shoes walks across a nylon carpet or linoleum tiled floor. With each step, electrons change places and the resulting electro-static charge builds up, quickly reaching significant levels. Pushing an epoxy printed circuit board across a workbench, using a plastic handled screwdriver or even the constant jostling of Styrofoam pellets during shipment can also build hefty static charges
TM
Table 11-1: Static Generation Voltages for Typical Activities
MEANS OF GENERATION
Walking across nylon carpet
Walking across vinyl tile
Worker at bench
65-90% RH
1,500V
250V
100V
10-25% RH
35,000V
12,000V
6,000V
Teledyne Analytical Instruments 255
ESD Model GFC7000TA Carbon Dioxide Analyzer
Poly bag picked up from bench
Moving around in a chair padded with urethane foam
1,200V 20,000V
1,500V 18,000V
11.2. How Electro-Static Charges Cause Damage
Damage to components occurs when these static charges come into contact with an electronic device.
Current flows as the charge moves along the conductive circuitry of the device and the typically very high voltage levels of the charge overheat the delicate traces of the integrated circuits, melting them or even vaporizing parts of them. When examined by microscope the damage caused by electro-static discharge looks a lot like tiny bomb craters littered across the landscape of the component’s circuitry.
A quick comparison of the values in Table 12-1 with the those shown in the Table 12-2, listing device susceptibility levels, shows why Semiconductor Reliability News estimates that approximately 60% of device failures are the result of damage due to electro-static discharge.
Table 11-2: Sensitivity of Electronic Devices to Damage by ESD
DAMAGE SUSCEPTIBILITY VOLTAGE
RANGE
DEVICE
DAMAGE BEGINS
OCCURRING AT
MOSFET 10
CATASTROPHIC
DAMAGE AT
100
VMOS 30
NMOS 60
GaAsFET 60
1800
100
2000
EPROM 100 100
JFET 140 7000
SAW 150 500
Op-AMP 190 2500
CMOS 200
Schottky Diodes 300
Film Resistors
This Film Resistors
300
300
3000
2500
3000
7000
ECL 500 500
SCR 500 1000
Schottky TTL 500 2500
Potentially damaging electro-static discharges can occur:
Any time a charged surface (including the human body) discharges to a device. Even simple contact of a finger to the leads of a sensitive device or assembly can allow enough discharge to cause damage. A similar discharge can occur from a charged conductive object, such as a metallic tool or fixture.
When static charges accumulated on a sensitive device discharges from the device to another surface such as packaging materials, work surfaces, machine surfaces or other device. In some cases, charged device discharges can be the most destructive.
A typical example of this is the simple act of installing an electronic assembly into the connector or wiring harness of the equipment in which it is to function. If the assembly is carrying a static charge, as it is connected to ground a discharge will occur.
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Whenever a sensitive device is moved into the field of an existing electro-static field, a charge may be induced on the device in effect discharging the field onto the device. If the device is then momentarily grounded while within the electrostatic field or removed from the region of the electrostatic field and grounded somewhere else, a second discharge will occur as the charge is transferred from the device to ground.
11.3. Common Myths About ESD Damage
I didn’t feel a shock so there was no electro-static discharge: The human nervous system isn’t able to feel a static discharge of less than 3500 volts. Most devices are damaged by discharge levels much lower than that.
I didn’t touch it so there was no electro-static discharge: Electro-static charges are fields whose lines of force can extend several inches or sometimes even feet away from the surface bearing the charge.
It still works so there was no damage: Sometimes the damaged caused by electro-static discharge can completely sever a circuit trace causing the device to fail immediately. More likely, the trace will be only partially occluded by the damage causing degraded performance of the device or worse, weakening the trace. This weakened circuit may seem to function fine for a short time, but even the very low voltage and current levels of the device’s normal operating levels will eat away at the defect over time causing the device to fail well before its designed lifetime is reached.
These latent failures are often the most costly since the failure of the equipment in which the damaged device is installed causes down time, lost data, lost productivity, as well as possible failure and damage to other pieces of equipment or property.
Static Charges can’t build up on a conductive surface: There are two errors in this statement.
Conductive devices can build static charges if they are not grounded. The charge will be equalized across the entire device, but without access to earth ground, they are still trapped and can still build to high enough levels to cause damage when they are discharged.
A charge can be induced onto the conductive surface and/or discharge triggered in the presence of a charged field such as a large static charge clinging to the surface of a nylon jacket of someone walking up to a workbench.
As long as my analyzer is properly installed, it is safe from damage caused by static discharges : It is true that when properly installed the chassis ground of your analyzer is tied to earth ground and its electronic components are prevented from building static electric charges themselves. This does not prevent discharges from static fields built up on other things, like you and your clothing, from discharging through the instrument and damaging it.
11.4. Basic Principles of Static Control
It is impossible to stop the creation of instantaneous static electric charges. It is not, however difficult to prevent those charges from building to dangerous levels or prevent damage due to electro-static discharge from occurring.
11.4.1. General Rules
Only handle or work on all electronic assemblies at a properly set up ESD station. Setting up an ESD safe workstation need not be complicated. A protective mat properly tied to ground and a wrist strap are all that is needed to create a basic anti-ESD workstation (see figure 12-2).
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ESD Model GFC7000TA Carbon Dioxide Analyzer
P r o t e c t iv e M a t
G r o u n d P o in t
W r is t S t r a p
Figure 11-2: Basic anti-ESD Work Station
For technicians that work in the field, special lightweight and portable anti-ESD kits are available from most suppliers of ESD protection gear. These include everything needed to create a temporary anti-ESD work area anywhere.
Always wear an Anti-ESD wrist strap when working on the electronic assemblies of your analyzer . An anti-ESD wrist strap keeps the person wearing it at or near the same potential as other grounded objects in the work area and allows static charges to dissipate before they can build to dangerous levels. Anti-ESD wrist straps terminated with alligator clips are available for use in work areas where there is no available grounded plug.
Also, anti-ESD wrist straps include a current limiting resistor (usually around one meg-ohm) that protects you should you accidentally short yourself to the instrument’s power supply.
Simply touching a grounded piece of metal is insufficient. While this may temporarily bleed off static charges present at the time, once you stop touching the grounded metal new static charges will immediately begin to re-build. In some conditions, a charge large enough to damage a component can rebuild in just a few seconds.
Always store sensitive components and assemblies in anti-ESD storage bags or bins:
Even when you are not working on them, store all devices and assemblies in a closed anti-Static bag or bin. This will prevent induced charges from building up on the device or assembly and nearby static fields from discharging through it.
Use metallic anti-ESD bags for storing and shipping ESD sensitive components and assemblies rather than pink-poly bags. The famous, “pink-poly” bags are made of a plastic that is impregnated with a liquid (similar to liquid laundry detergent) which very slowly sweats onto the surface of the plastic creating a slightly conductive layer over the surface of the bag.
While this layer may equalizes any charges that occur across the whole bag, it does not prevent the build up of static charges. If laying on a conductive, grounded surface, these bags will allow charges to bleed away but the very charges that build up on the surface of the bag itself can be transferred through the bag by induction onto the circuits of your ESD sensitive device. Also, the liquid impregnating the plastic is eventually used up after which the bag is as useless for preventing damage from ESD as any ordinary plastic bag.
Anti-Static bags made of plastic impregnated with metal (usually silvery in color) provide all of the charge equalizing abilities of the pink-poly bags but also, when properly sealed, create a Faraday cage that completely isolates the contents from discharges and the inductive transfer of static charges.
Storage bins made of plastic impregnated with carbon (usually black in color) are also excellent at dissipating static charges and isolating their contents from field effects and discharges.
Never use ordinary plastic adhesive tape near an ESD sensitive device or to close an anti-
®
ESD bag. The act of pulling a piece of standard plastic adhesive tape, such as Scotch tape, from its roll will generate a static charge of several thousand or even tens of thousands of volts on the tape itself and an associated field effect that can discharge through or be induced upon items up to a foot away.
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ESD Model GFC7000TA Carbon Dioxide Analyzer
11.4.2. Basic anti-ESD Procedures for Analyzer Repair and
Maintenance
11.4.2.1. Working at the Instrument Rack
When working on the analyzer while it is in the instrument rack and plugged into a properly grounded power supply.
1. Attach your anti-ESD wrist strap to ground before doing anything else.
Use a wrist strap terminated with an alligator clip and attach it to a bare metal portion of the instrument chassis. This will safely connect you to the same ground level to which the instrument and all of its components are connected.
2. Pause for a second or two to allow any static charges to bleed away.
3. Open the casing of the analyzer and begin work. Up to this point, the closed metal casing of your analyzer has isolated the components and assemblies inside from any conducted or induced static charges.
4. If you must remove a component from the instrument, do not lay it down on a non-ESD preventative surface where static charges may lie in wait.
5. Only disconnect your wrist strap after you have finished work and closed the case of the analyzer.
11.4.2.2. Working at an Anti-ESD Work Bench.
When working on an instrument of an electronic assembly while it is resting on an anti-ESD work bench:
1. Plug your anti-ESD wrist strap into the grounded receptacle of the work station before touching any items on the work station and while standing at least a foot or so away. This will allow any charges you are carrying to bleed away through the ground connection of the workstation and prevent discharges due to field effects and induction from occurring.
2. Pause for a second or two to allow any static charges to bleed away.
3. Only open any anti-ESD storage bins or bags containing sensitive devices or assemblies after you have plugged your wrist strap into the workstation.
Lay the bag or bin on the workbench surface.
Before opening the container, wait several seconds for any static charges on the outside surface of the container to be bled away by the workstation’s grounded protective mat.
4. Do not pick up tools that may be carrying static charges while also touching or holding an ESD
Sensitive Device.
Only lay tools or ESD-sensitive devices and assemblies on the conductive surface of your workstation. Never lay them down on any non-ESD preventative surface.
5. Place any static sensitive devices or assemblies in anti-static storage bags or bins and close the bag or bin before unplugging your wrist strap.
6. Disconnecting your wrist strap is always the last action taken before leaving the workbench.
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ESD Model GFC7000TA Carbon Dioxide Analyzer
11.4.2.3. Transferring Components from Rack to Bench and Back
When transferring a sensitive device from an installed Teledyne Instruments analyzer to an Anti-ESD workbench or back:
1. Follow the instructions listed above for working at the instrument rack and workstation.
2. Never carry the component or assembly without placing it in an anti-ESD bag or bin.
3. Before using the bag or container allow any surface charges on it to dissipate:
If you are at the instrument rack, hold the bag in one hand while your wrist strap is connected to a ground point.
If you are at an anti-ESD workbench, lay the container down on the conductive work surface.
In either case wait several seconds.
4. Place the item in the container.
5. Seal the container. If using a bag, fold the end over and fastening it with anti-ESD tape.
Folding the open end over isolates the component(s) inside from the effects of static fields.
Leaving the bag open or simply stapling it shut without folding it closed prevents the bag from forming a complete protective envelope around the device.
6. Once you have arrived at your destination, allow any surface charges that may have built up on the bag or bin during travel to dissipate:
Connect your wrist strap to ground.
If you are at the instrument rack, hold the bag in one hand while your wrist strap is connected to a ground point.
If you are at a anti-ESD work bench, lay the container down on the conductive work surface
In either case wait several seconds
11.4.2.4. Opening Shipments from Teledyne Instruments Customer Service.
Packing materials such as bubble pack and Styrofoam pellets are extremely efficient generators of static electric charges. To prevent damage from ESD, Teledyne Instruments ships all electronic components and assemblies in properly sealed anti-ESD containers.
Static charges will build up on the outer surface of the anti-ESD container during shipping as the packing materials vibrate and rub against each other. To prevent these static charges from damaging the components or assemblies being shipped make sure that you always unpack shipments from Teledyne
Instruments Customer Service by:
1. Opening the outer shipping box away from the anti-ESD work area.
2. Carry the still sealed ant-ESD bag, tube or bin to the anti-ESD work area.
3. Follow steps 6 and 7 of Section 11.4.2.3 above when opening the anti-ESD container at the work station.
4. Reserve the anti-ESD container or bag to use when packing electronic components or assemblies to be returned to Teledyne Instruments.
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ESD Model GFC7000TA Carbon Dioxide Analyzer
11.4.2.5. Packing Components for Return to Teledyne Instruments Customer
Service.
Always pack electronic components and assemblies to be sent to Teledyne Instruments Customer
Service in anti-ESD bins, tubes or bags.
WARNING
DO NOT
use pink-poly bags.
NEVER
allow any standard plastic packaging materials to touch the electronic component/assembly directly
This includes
,
but is not limited to, plastic bubble-pack, Styrofoam peanuts, open cell foam, closed cell foam, and adhesive tape
DO NOT use standard adhesive tape as a sealer. Use ONLY anti-ESD tape
1. Never carry the component or assembly without placing it in an anti-ESD bag or bin.
2. Before using the bag or container allow any surface charges on it to dissipate:
If you are at the instrument rack, hold the bag in one hand while your wrist strap is connected to a ground point.
If you are at an anti-ESD workbench, lay the container down on the conductive work surface.
In either case wait several seconds.
3. Place the item in the container.
4. Seal the container. If using a bag, fold the end over and fastening it with anti-ESD tape.
Folding the open end over isolates the component(s) inside from the effects of static fields.
Leaving the bag open or simply stapling it shut without folding it closed prevents the bag from forming a complete protective envelope around the device.
NOTE
:
If you do not already have an adequate supply of anti-ESD bags or containers available, Teledyne
Instruments’ Customer Service department will supply them. Follow the instructions listed above for working at the instrument rack and workstation.
Teledyne Analytical Instruments 261
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Table of contents
- 19 1. INTRODUCTION
- 19 1.1. Features
- 19 1.2. Using This Manual
- 23 2. SPECIFICATIONS AND APPROVALS
- 23 2.1. Specifications
- 25 2.2. CE Mark Compliance
- 27 3. GETTING STARTED
- 27 3.1. Unpacking and Initial Set Up
- 29 3.2. Front Panel
- 33 3.3. Rear Panel
- 35 3.4. Internal Layout
- 37 3.5. Electrical Connections
- 38 3.5.1. Power Connection
- 38 3.5.2. Connecting Analog Inputs (Option 64)
- 39 3.5.3. Connecting Analog Outputs
- 41 3.5.4. Connecting the Status Outputs
- 42 3.5.5. Connecting the Control Inputs
- 43 3.5.6. Connecting the Communications Interfaces
- 43 3.6. Pneumatic Connections
- 44 3.6.1. Basic Pneumatic Connections
- 48 3.6.2. Connections with Internal Valve Options Installed
- 50 3.6.3. Pneumatic Connections in Multipoint Calibration Applications
- 50 3.6.4. Setting the Internal Purge Air Pressure
- 51 3.7. Initial Operation
- 51 3.7.1. Startup
- 52 3.7.2. Warm Up
- 52 3.7.3. Warning Messages
- 54 3.7.4. Functional Check
- 55 3.8. Initial Calibration Procedure
- 58 Sensor Calibration Procedure
- 63 4. FREQUENTLY ASKED QUESTIONS
- 63 4.1. FAQ’s
- 64 4.2. Glossary
- 69 5. OPTIONAL HARDWARE AND SOFTWARE
- 69 5.1. Rack Mount Kits (Options 20A, 20B, 21 and 23)
- 69 5.2. Current Loop Analog Outputs (Option 41)
- 70 5.2.1. Converting Current Loop Analog Outputs to Standard Voltage Outputs
- 71 5.3. Expendable Kits (Options 42C, 42D and 43)
- 72 5.4. Calibration Valves Options
- 72 5.4.1. Ambient Zero/Pressurized Span Valve
- 73 5.4.2. Ambient Zero/Ambient Span Valve
- 75 5.5. Communication Options
- 75 5.5.1. Communications Cables
- 75 5.5.2. RS-232 Multidrop (Option 62)
- 76 5.6. Oxygen Sensor (OPT 65)
- 76 5.6.1. Theory of Operation
- 79 5.7. Special Features
- 79 5.7.1. Dilution Ratio Option
- 79 5.7.2. Maintenance Mode Switch
- 79 5.7.3. Second Language Switch
- 81 6. OPERATING INSTRUCTIONS
- 81 6.1. Overview of Operating modes
- 82 6.2. Sample Mode
- 83 6.2.1. Test Functions
- 85 6.2.2. Warning Messages
- 86 6.3. Calibration Mode
- 87 6.4. SETUP MODE
- 88 6.5. SETUP CFG: Viewing the Analyzer’s Configuration Information
- 88 6.6. SETUP ACAL: Automatic Calibration
- 89 6.7. SETUP DAS: Using the Data Acquisition System (DAS)
- 90 6.7.1. DAS Structure
- 92 6.7.2. Default DAS Channels
- 106 6.7.3. Remote DAS Configuration
- 107 6.8. SETUP RNGE: Analog Output Reporting Range Configuration
- 108 6.8.1. Physical Range versus Analog Output Reporting Ranges
- 108 6.8.2. Reporting Range Modes
- 110 6.8.3. Single Range Mode (SNGL)
- 111 6.8.4. Dual Range Mode (DUAL)
- 112 6.8.5. Auto Range Mode (AUTO)
- 113 6.8.6. Range Units
- 114 6.8.7. Dilution Ratio
- 115 6.9. SETUP PASS: Password Feature
- 117 6.10. SETUP CLK: Setting the Internal Time-of-Day Clock
- 119 6.11. SETUP MORE COMM: Using the Analyzer’s Communication Ports
- 119 6.11.1. Analyzer ID
- 120 6.11.2. COM Port Default Settings
- 123 6.11.3. RS-485 Configuration of COM
- 123 6.11.4. DTE and DCE Communication
- 124 6.11.5. COM Port Communication Modes
- 126 6.11.6. Remote Access via the Ethernet
- 132 6.11.7. Multidrop RS-232 Set Up
- 134 6.11.8. COM Port Baud Rate
- 135 6.11.9. COM Port Testing
- 136 6.12. SETUP MORE VARS: Internal Variables (VARS)
- 138 6.13. SETUP MORE DIAG: Using the Diagnostics Functions
- 139 6.13.1. Accessing the Diagnostic Features
- 139 6.13.2. Signal I/O
- 140 6.13.3. Analog Output Step Test
- 141 6.13.4. Analog I/O Configuration
- 154 6.13.5. Electric Test
- 155 6.13.6. Dark Calibration Test
- 156 6.13.7. Pressure Calibration
- 157 6.13.8. Flow Calibration
- 158 6.13.9. Test Channel Output
- 159 6.14. SETUP MORE ALRM: Using the Gas Concentration Alarms
- 160 6.14.1. Setting the Concentration Alarm Limits
- 160 6.15. Remote Operation of the Analyzer
- 160 6.15.1. Remote Operation Using the External Digital I/O
- 164 6.15.2. Remote Operation Using the External Serial I/O
- 171 6.15.3. Additional Communications Documentation
- 171 6.15.4. Using the GFC 7000TA with a Hessen Protocol Network
- 179 7. CALIBRATION PROCEDURES
- 179 7.1. Before Calibration
- 179 7.1.1. Zero Air and Span Gas
- 180 7.1.2. Calibration Gas Traceability
- 180 7.1.3. Data Recording Devices
- 180 7.2. Manual Calibration without Zero/Span Valves
- 183 7.3. Manual Calibration Checks
- 184 7.4. Manual Calibration with Zero/Span Valves
- 189 7.5. Manual Calibration Checks with Zero/Span Valves
- 190 7.5.1. Zero/Span Calibration on Auto Range or Dual Ranges
- 191 7.5.2. Use of Zero/Span Valves with Remote Contact Closure
- 191 7.6. Automatic Zero/Span Cal/Check (AutoCal)
- 194 7.6.1. AutoCal with Auto or Dual Reporting Ranges Modes Selected
- 194 7.7. Calibration Quality
- 197 8. MAINTENANCE SCHEDULE & PROCEDURES
- 197 8.1. Maintenance Schedule
- 201 8.2. Predicting Failures Using the Test Functions
- 202 8.3. Maintenance Procedures
- 202 8.3.1. Replacing the Sample Particulate Filter
- 203 8.3.2. Rebuilding the Sample Pump
- 203 8.3.3. Performing Leak Checks
- 204 8.3.4. Performing a Sample Flow Check
- 204 8.3.5. Cleaning the Optical Bench
- 204 8.3.6. Cleaning Exterior Surfaces of the GFC 7000TA
- 205 9. THEORY OF OPERATION
- 205 9.1. Measurement Method
- 205 9.1.1. Beer’s Law
- 205 9.1.2. Measurement Fundamentals
- 206 9.1.3. Gas Filter Correlation
- 208 9.1.4. Interference and Signal to Noise Rejection
- 211 9.2. Pneumatic Operation
- 212 9.2.1. Sample Gas Flow
- 212 9.2.2. Flow Rate Control
- 214 9.2.3. Purge Gas Pressure Control
- 214 9.2.4. Particulate Filter
- 214 9.2.5. Pneumatic Sensors
- 215 9.3. Electronic Operation
- 215 9.3.1. Overview
- 217 9.3.2. CPU
- 218 9.3.3. Optical Bench & GFC Wheel
- 220 9.3.4. Synchronous Demodulator (Sync/Demod) Assembly
- 223 9.3.5. Relay Board
- 225 9.3.6. Mother Board
- 228 C Data Bus
- 229 9.3.8. Power Supply/ Circuit Breaker
- 230 9.4. Front Panel Touchscreen/Display Interface
- 230 9.4.1. LVDS Transmitter Board
- 230 9.4.2. Front Panel Touchscreen/Display Interface PCA
- 231 9.5. Software Operation
- 231 9.5.1. Adaptive Filter
- 232 9.5.2. Calibration - Slope and Offset
- 232 9.5.3. Measurement Algorithm
- 233 9.5.4. Temperature and Pressure Compensation
- 233 9.5.5. Internal Data Acquisition System (DAS)
- 235 10. TROUBLESHOOTING & REPAIR PROCEDURES
- 235 10.1. General Troubleshooting Hints
- 236 10.1.1. Interpreting WARNING Messages
- 239 10.1.2. Fault Diagnosis with TEST Functions
- 241 10.1.3. Using the Diagnostic Signal I/O Function
- 242 10.1.4. Internal Electronic Status LEDs
- 246 10.2. Gas Flow Problems
- 247 10.2.1. GFC 7000TA Internal Gas Flow Diagrams
- 250 10.2.2. Typical Sample Gas Flow Problems
- 252 10.2.3. Poor or Stopped Flow of Purge Gas
- 253 10.3. Calibration Problems
- 253 10.3.1. Miscalibrated
- 254 10.3.2. Non-Repeatable Zero and Span
- 254 10.3.3. Inability to Span – Touchscreen SPAN Button Not Visible
- 255 10.3.4. Inability to Zero – Touchscreen ZERO Button Not Visible
- 256 10.4. Other Performance Problems
- 256 10.4.1. Temperature Problems
- 258 10.4.2. Excessive Noise
- 259 10.5. Subsystem Checkout
- 259 10.5.1. AC Mains Configuration
- 259 10.5.2. DC Power Supply
- 260 C Bus
- 260 10.5.4. Touchscreen Interface
- 260 10.5.5. LCD Display Module
- 261 10.5.6. Relay Board
- 261 10.5.7. Sensor Assembly
- 263 10.5.8. Motherboard
- 267 10.5.9. CPU
- 267 10.5.10. RS-232 Communications
- 269 10.6. Repair Procedures
- 269 10.6.1. Repairing Sample Flow Control Assembly
- 270 10.6.2. Removing/Replacing the GFC Wheel
- 271 10.6.3. Disk-On-Module Replacement Procedure
- 273 11. A PRIMER ON ELECTRO-STATIC DISCHARGE
- 273 11.1. How Static Charges are Created
- 274 11.2. How Electro-Static Charges Cause Damage
- 275 11.3. Common Myths About ESD Damage
- 275 11.4. Basic Principles of Static Control