Keithley 2001 TCSCAN Thermocouple Scanner Card, 2000, 2001, 2002, 2010 Multimeter, 7401 Type K Thermocouple Wire Kit, 8530 Centronics Printer Adapter, 8681 Miniature Surface RTD Probe Instruction Manual
Below you will find brief information for Thermocouple Scanner Card 2001 TCSCAN, Multimeter 2000, Multimeter 2001, Multimeter 2002, Multimeter 2010. The Keithley 2001-TCSCAN is a scanner card designed to be installed in the Keithley 2000, 2001, 2002, or 2010 Multimeter. Key features include a built-in reference junction (channel 1), low contact potential and offset current, input connectors that are in contact with an isothermal block to minimize temperature differences, nine channels of 2-pole relay input, four channel pairs configurable for 4-pole operation, and the ability to multiplex one of nine 2-pole, or one of four 4-pole channels into the DMM.
advertisement
Model 2001-TCSCAN
Scanner Card
Instruction Manual
Contains Operating and Servicing Information
WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility.
Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN
ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRU-
MENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POS-
SIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS
OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAM-
AGE TO PROPERTY.
Keithley Instruments, Inc.
• 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: 440-248-6168 • http://www.keithley.com
CHINA:
FRANCE:
Keithley Instruments China
• Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • Fax: 8610-62022892
Keithley Instruments SARL
• BP 60 • 3 Allée des Garays • 91122 Palaiseau Cédex • 33-1-60-11-51-55 • Fax: 33-1-60-11-77-26
GERMANY: Keithley Instruments GmbH
• Landsberger Strasse 65 • D-82110 Germering, Munich • 49-89-8493070 • Fax: 49-89-84930759
GREAT BRITAIN: Keithley Instruments, Ltd.
• The Minster • 58 Portman Road • Reading, Berkshire, England RG3 1EA • 44-1189-596469 • Fax: 44-1189-575666
ITALY: Keithley Instruments SRL
• Viale S. Gimignano 38 • 20146 Milano • 39-2-48303008 • Fax: 39-2-48302274
NETHERLANDS: Keithley Instruments BV
• Avelingen West 49 • 4202 MS Gorinchem • 31-(0)183-635333 • Fax: 31-(0)183-630821
SWITZERLAND: Keithley Instruments SA
• Kriesbachstrasse 4 • 8600 Dübendorf • 41-1-8219444 • Fax: 41-1-8203081
TAIWAN: Keithley Instruments Taiwan
• 1FL., 85 Po Ai Street • Hsinchu, Taiwan • 886-3-572-9077 • Fax: 886-3-572-9031
1/99
Model 2001-TCSCAN
Instruction Manual
©1993, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Second Printing, January 1997
Document Number: 2001-TCSC-901-01 Rev. B
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The
Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially. When a new Revision is created, all Addenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this print history page.
Revision A (Document Number 2001-TCSC-901-01) .................................................................... March 1993
Addendum A (Document Number 2001-TCSC-901-02) .......................................................November 1995
Revision B (Document Number 2001-TCSC-901-01) ................................................................. January 1997
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.
Safety Precautions
The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information carefully before using the product.
The types of product users are:
Responsible body
is the individual or group responsible for the use and maintenance of equipment, for ensuring that the equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators
use the product for its intended function. They must be trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel
perform routine procedures on the product to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.
Service personnel
are trained to work on live circuits, and perform safe installations and repairs of products. Only properly trained service personnel may perform installation and service procedures.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present.
A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring.
Users of this product must be protected from electric shock at all times. The responsible body must ensure that users are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human contact. Product users in these circumstances must be trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or above 1000 volts,
no conductive part of the circuit may be exposed.
As described in the International Electrotechnical Commission
(IEC) Standard IEC 664, digital multimeter measuring circuits
(e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are
Installation Category II. All other instruments’ signal terminals are
Installation Category I and must not be connected to mains.
Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground.
Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a lid interlock.
If a screw is present, connect it to safety earth ground using the wire recommended in the user documentation.
The
!
symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.
The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages.
The
WARNING
heading in a manual explains dangers that might result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
The
CAUTION
heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product.) If you are unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.
Rev. 2/99
HERMOCOUPLE
ENERAL
URPOSE
CANNER
ARD
PECIFICATIONS
Thermocouple Accuracy
Total Absolute Error
1
1 Year
Thermocouple
Type Range
Default
Resolution 18
°
–28
°
C
0
°
–18
°
C &
28
°
–50
°
C
1
J
K
T
E
R
S
B
–100 to 760
°
C
–100 to 1372
°
C
–100 to 400
°
C
–100 to 1000
°
C
0 to 1768
°
C
0 to 1768
°
C
350 to 1820
°
C
When used with Model 2001 Multimeter.
Specifications apply to channels 2–6. Add 0.06
°
C for each adjacent channel away from channel 6.
Extended range (Types J, K, T, E): -200. 0
°
C to -100. 1
°
C add
±
0.1
°
C.
Excluding thermocouple error.
0.1
°
C
0.1
°
C
0.1
°
C
0.1
°
C
1.0
°
C
1.0
°
C
1.0
°
C
±
0.65
°
C
±
0.70
°
C
±
0.68
°
C
±
0.67
°
C
±
1.31
°
C
±
1.30
°
C
±
1.65
°
C
±
1.08
°
C
±
1.32
°
C
±
1.22
°
C
±
1.11
°
C
±
3.06
°
C
±
3.02
°
C
±
4.14
°
C
Ordering Information
2001-TCSCAN 9 Channel Thermocouple/General Purpose Scanner
2001 High Performance 7 1 ⁄
2
-Digit Multimeter
2001/MEM1
2001/MEM2
Base 2001 plus additional memory. Store up to 6000 readings
Base 2001 plus additional memory. Store up to 30000 readings
7401
8530
8681
Type K Thermocouple Wire Kit (100 ft)
Centronics Printer Adapter
Miniature Surface RTD Probe
Specifications subject to change without notice.
Specifications
GENERAL: 9 channels of 2-pole analog input, 1 cold junction sensor.
FUNCTIONS: DCV, ACV, 4-wire
Ω
, Thermocouple, 2-wire
Ω
, 4-wire RTD, 2wire RTD, Frequency (can be mixed from channel to channel).
THERMOCOUPLE SCAN SPEED: 25 channels/second @ 0.1
°
C resolution;
43 channels/second @ 1
°
C resolution.
CAPABILITIES: Multiplex one of nine 2-pole or one of four 4-pole analog signals into Model 2001 DMM and/or any combination of 2- or 4-pole analog signals.
REFERENCE OUTPUT: +200
µ
V/
°
C (+54.63mV at 0
°
C).
ALL INPUTS
Maximum Signal Levels 2 :
DC: 110V DC, <1A switched, 30VA maximum (resistive load).
AC: 125V AC rms or 175V AC peak, 1A switched, 62.5VA maximum
(resistive load).
Contact Life: >10 5 cold switching.
operations at maximum signal level; >10 8 operations
Contact Resistance 2
: <1
Ω
at end of contact life.
Actuation Time: 2.5ms maximum on/off.
Contact Potential 3
: <
±
500nV typical per contact, 1
µ
V max.
Connector Type: Screw terminal, #22 AWG wire size (0.062 O.D.).
Isolation Between Any Two Terminals: >10 9 , <75pF.
Common Mode Voltage: 350V peak between any terminal and earth.
Maximum Voltage Between Any Two Terminals: 110VDC, 125VAC RMS.
DIMENSIONS, WEIGHT: 21mm high
×
72mm wide
×
221mm deep (0.83 in
×
2.83 in
×
8.7 in). Net weight 283g (10 oz).
2
3
Channels 5 and 10 maximum power = 0.25 VA maximum (factory installed
120
Ω
, 5%, 1/4W resistors. User may replace with jumper. See note in manual for complete instructions.)
Channels 5 and 10 contact potential =
±
1
µ
V typical, 2
µ
V max.
Channel 1
(Reference
Junction)
Channel 2-4
HI
Channel 5
LO
2-Pole
HI
LO
OUT A (To Model 2001
input jacks)
HI
LO
OUT B (To Model 2001
sense jacks)
4-Pole
Channel 6
HI
LO
Channel 7-9
HI
Channel 10
LO
Table of Contents
1 General Information
1.5
1.7
1.7.1
1.7.2
1.7.3
1.7.4
1.8
1.9
2 Card Connections and Installation
2.4.2
2.4.3
2.5
2.5.1
2.5.2
2.5.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.4
2.4.1
i
3 Operation
3.12
3.12.1
3.12.2
3.13
3.13.1
3.13.2
3.13.3
3.13.4
3.13.5
3.13.6
3.13.7
3.9.1
3.9.2
3.9.3
3.10
3.10.1
3.10.2
3.11
3.11.1
3.7.1
3.7.2
3.8
3.8.1
3.8.2
3.8.3
3.8.4
3.9
3.4.5
3.4.6
3.5
3.6
3.6.1
3.6.2
3.3
3.3.1
3.3.2
3.4
3.4.1
3.4.2
3.4.3
3.4.4
ii
4 Service Information
4.2
4.2.1
4.2.2
4.6.5
4.7
4.7.1
4.7.2
4.7.3
4.8
4.4.1
4.4.2
4.5
4.6
4.6.1
4.6.2
4.6.3
4.6.4
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.3.6
4.3.7
5 Replaceable Parts
5.5
A
A.1
A.2
A.3
A.4
B
Thermocouple Basics
Thermocouple Conversion Tables
iii
List of Illustrations
2
Figure 2-1
Figure 2-2
Figure 2-3
Figure 2-4
Figure 2-5
Figure 2-6
Figure 2-7
Figure 2-8
Figure 2-9
Figure 2-10
Figure 2-11
Card Connections and Installation
3
Figure 3-1
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10
Operation
v
4
Figure 4-1
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-8
Figure 4-9
Figure 4-10
Service Information
A
Figure A-1
Thermocouple Basics
vi
List of Tables
3
Table 3-1
Table 3-2
Table 3-3
Operation
4
Table 4-1
Table 4-2
Table 4-3
Service Information
5
Table 5-1
Table 5-2
Replaceable Parts
B
Table B-1
Thermocouple Conversion Tables
vii
General Information
1.1
Introduction
This section contains general information about the Model
2001-TCSCAN General Purpose/Thermocouple Scanner
Card, which is designed to be used with the Model 2000,
2001, 2002, and 2010 DMMs to make accurate multi-channel thermocouple measurements. The DMMs will automatically convert type J, K, T, E, R, S, and B thermocouple voltages to
Celsius, Fahrenheit, or Kelvin temperature readings.
The Model 2001-TCSCAN can also be used for a variety of nine-channel, mixed-signal switching applications. The
500nV-125V signal voltage range of the Model 2001-
TCSCAN makes it well suited for both low and high signal levels.
1.2
Features
The Model 2001-TCSCAN is a scanner card designed to be installed in the Model 2000, 2001, 2002, or 2010 Multimeter.
Key features include:
• Built-in reference junction (channel 1).
• Low contact potential and offset current.
• Input connectors are in contact with an isothermal block to minimize temperature differences.
• Nine channels of 2-pole relay input.
• Four channel pairs configurable for 4-pole operation.
• Multiplex one of nine 2-pole, or one of four 4-pole channels into the DMM.
Section 1 is arranged in the following manner:
1.2
Features
1.3
Warranty information
1.4
Manual addenda
1.5
Safety symbols and terms
1.6
Specifications
1.7
Unpacking and inspection
1.8
Repacking for shipment
1.9
Optional accessories
1.3
Warranty information
Warranty information is located on the inside front cover of this instruction manual. Should your Model 2001-TCSCAN require warranty service, contact the Keithley representative or authorized repair facility in your area for further information. When returning the scanner card for repair, be sure to fill out and include the service form at the back of this manual in order to provide the repair facility with the necessary information.
1-1
1.4
Manual addenda
Any improvements or changes concerning the scanner card or manual will be explained in an addendum included with the card. Addenda are provided in a page replacement format. Simply replace the obsolete pages with the new pages.
1.7
Unpacking and inspection
1.7.1 Inspection for damage
The Model 2001-TCSCAN is packaged in a re-sealable, anti-static bag to protect it from damage due to static discharge and from contamination that could degrade its performance. Before removing the card from the bag, observe the precautions below on handling.
1.5
Safety symbols and terms
The following symbols and terms may be found on an instrument or used in this manual.
!
The symbol on an instrument indicates that the user should refer to the operating instructions located in the instruction manual.
1.7.2 Handling precautions
• Always grasp the card by the side edges and covers. Do not touch the board surfaces or components.
• When the card is not installed in a DMM, keep the card in the anti-static bag, and store it in the original packing carton. After removing the card from its anti-static bag, inspect it for any obvious signs of physical damage.
Report any such damage to the shipping agent immediately.
The symbol an instrument shows that high voltage may be present on the terminal(s). Use standard safety precautions to avoid personal contact with these voltages.
The
WARNING
heading used in this manual explains dangers that might result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
The
CAUTION
heading used in this manual explains hazards that could damage the scanner card. Such damage may invalidate the warranty.
1.7.3 Shipment contents
The following items are included with every Model 2001-
TCSCAN order:
• Model 2001-TCSCAN Scanner Card
• Model 2001-TCSCAN Instruction Manual
• CA-109 test lead set for output connections (two red, two black)
• Additional accessories as ordered
1.6
Specifications
Model 2001-TCSCAN specifications are found at the front of this manual. All specifications except temperature accuracy are exclusive of the DMM specifications. Temperature accuracy specifications include DMM temperature accuracy.
Note that Model 2001-TCSCAN scan temperature accuracy is specified down to -100°C. For temperatures from -100.1°C and -200°C using type J, K, T, or E thermocouples, add an additional ±0.1°C of error.
1.7.4 Instruction manual
If an additional Model 2001-TCSCAN Instruction Manual is required, order the manual package, Keithley part number
2001-TCSC-901-00. The manual package includes an instruction manual and any pertinent addenda.
1-2
1.8
Repacking for shipment
Should it become necessary to return the Model 2001-TCSCAN for repair, carefully pack the unit in its original packing carton or the equivalent, and include the following information:
• Advise as to the warranty status of the scanner card.
• Write ATTENTION REPAIR DEPARTMENT on the shipping label.
• Fill out and include the service form located at the back of this manual.
1.9
Optional accessories
Model 7401
— The Model 7401 is a thermocouple wire kit that includes 30.5m (100 ft.) of type K (chromel-alumel) thermocouple wire.
1-3
Card Connections and Installation
2.1
Introduction
WARNING
The procedures in this section are intended only for qualified service personnel. Do not perform these procedures unless you are qualified to do so. Failure to recognize and observe normal safety precautions could result in personal injury or death.
2.2
Handling precautions
To maintain high impedance isolation between channels, care should be taken when handling the scanner card to avoid contamination from such foreign materials as body oils.
Such contamination can substantially lower leakage resistances, degrading card performance. To avoid possible contamination, always grasp the scanner card by the side edges or covers. Do not touch board surfaces, components, or areas adjacent to electrical contacts.
This section includes information on making connections to the Model 2001-TCSCAN and on installing the card in the
DMM. This section is arranged as follows:
2.2
Handling precautions:
Explains precautions that must be followed to prevent contamination to the scanner card assembly. Contamination could degrade the performance of the scanner card.
2.3
Connections:
Covers the basics for connecting external circuitry to the scanner card.
2.4
Typical connection schemes:
Provides some typical connection schemes for 2-pole and 4-pole operation, including thermocouple connections.
2.5
Card installation and removal:
Summarizes the procedure to install the scanner card in the DMM, outlines scanner card output connections, and describes how to remove the card.
Dirt build-up over a period of time is another possible source of contamination. To avoid this problem, operate the multimeter and scanner card in a clean environment. If the card becomes contaminated, it should be thoroughly cleaned as explained in paragraph 4.2.
2.3
Connections
This paragraph provides the information necessary to connect your thermocouples or other external test circuitry to the scanner card.
WARNING
The following connection information is intended to be used by qualified service personnel. Failure to recognize and observe standard safety precautions could result in personal injury or death.
2-1
Card Connections and Installation
NOTE
All connecting wires or leads must be connected to the card before it is installed in the DMM.
2.3.1 Card configuration
Figure 2-1 shows a simplified schematic diagram of the
Model 2001-TCSCAN. The scanner card has nine input channels and two outputs. Channel 1 is the reference junction used for thermocouple temperature measurements.
4-pole paired channels are as follows:
• Channels 2 and 7
• Channels 3 and 8
• Channels 4 and 9
• Channels 5 and 10
CAUTION
Do not attempt to pair channels 1 and 6.
Possible damage to the reference junction may result if a signal is applied to channel 6 if channels 1 and 6 are used together in the 4-pole mode.
Channel 1
(Reference
Junction)
Channel 2-4
HI
Channel 5
LO
2-Pole
HI
LO
OUT A (To DMM
input jacks)
HI
LO
OUT B (To DMM
sense jacks)
Channel 6
HI
LO
Channel 7-9
HI
Channel 10
LO
Figure 2-1
Model 2001-TCSCAN simplified schematic
2-2
4-Pole
Card Connections and Installation
2.3.2 Card connectors
Figure 2-2 shows the input/output connectors for the card.
Card connections include:
• CH 2-10 (channels 2-10): HI and LO input terminals are provided for each of the nine channels on the card.
NOTE
Channels 5 and 10 have current-limiting resistors installed. Path resistance for these two channels is approximately
240
Ω
.
• OUT A: HI and LO output connections for all nine channels in the 2-pole mode or channels 2-5 in the 4pole mode.
• OUT B: HI and LO output connections for channels 7-
10 in the 4-pole mode.
In order to gain access to the connections, first open the plastic shield by pressing in on the locking tab. Swing the shield away from the circuit board.
2.3.3 Wiring procedure
Perform the following procedure to wire circuitry to the screw terminals on the scanner card.
WARNING
Make sure all power is off and any stored energy in external circuitry is discharged before connecting or disconnecting wires.
CAUTION
Mechanical shock may open or close latching relays on the scanner card. Before enabling any external sources, open all relays by inserting the Model 2001-
TCSCAN into the DMM and turning on the power.
Reference Junction Sensor
Input/Output Connectors
HI LO
CH 2
HI LO
CH 3
HI LO
CH 4
HI LO
CH 5
HI LO
CH 6
HI LO
CH 7
HI LO
CH 8
HI LO
CH 9
HI LO
CH 10
HI LO HI LO
OUT A OUT B
Plastic Shield
Reference Junction Circuitry
Locking Tab
Figure 2-2
Card connectors
2-3
Card Connections and Installation
1. Open the plastic shield to gain access to the connectors.
2. Strip approximately
¼
” of insulation from the end of each wire.
NOTE
Standard thermocouple wire or #22 AWG stranded wire is recommended for scanner card connections.
3. Turn the screw terminal several turns counter-clockwise until the access hole is open. Insert the wire in the access hole.
4. While holding the wire in place, tighten the connector screw securely.
CAUTION
Be sure not to over tighten screw terminals, or the connectors may be damaged.
5. Repeat steps 2 through 4 for each wire to be connected.
6. Dress input wires through the cable clamp, as discussed in paragraph 2.3.5.
WARNING
If thermocouples are going to be floated above 30V RMS, 42.4V peak, 60VDC, make sure thermocouple wires have adequate insulation.
2.3.4 Output connections
Use the supplied test leads for scanner output connections.
Connect red leads to the output (OUT A and OUT B) HI terminals, and connect black leads to the output LO terminals.
See Figure 2-3 for details. Dress output test leads through the cable clamp, as described in paragraph 2.3.5. After all wires are connected and secure, close the plastic shield, and secure it with the locking tab.
NOTE
If you intend to use the scanner card only in the 2-pole mode, it is not necessary to connect output leads to both OUT A and
OUT B. Use only OUT A for the 2-pole mode.
After the scanner card is installed, the output leads must be connected to the multimeter rear panel input jacks. See paragraph 2.5.2 for details.
2.3.5 Dressing leads
After wires are connected to the terminal blocks, they should be dressed through the cable clamp as shown in Figure 2-4.
To do so, unlatch the clip that holds the cable clamp together, then route all wires flat against the lower half of the clamp.
Clamp the wires down, then secure the clamp with the metal clip unlatched earlier.
2-4
Red
HI
LO
To DMM
Input Jacks
Red
Black
Card Connections and Installation
HI
LO
To DMM
Sense Jacks
Black
HI LO
CH 2
HI LO HI LO
CH 3 CH 4
HI LO
CH 5
HI LO
CH 6
HI LO
CH 7
HI LO HI LO
CH 8 CH 9
HI LO
CH 10
HI LO HI LO
OUT A OUT B
Figure 2-3
Output connections
Note: OUT B connections not required
for 2-pole operation.
Metal Clip
HI LO
CH 2
HI LO
CH 3
HI LO
CH 4
HI LO
CH 5
HI LO
CH 6
HI LO
CH 7
HI LO
CH 8
HI LO
CH 9
HI LO
CH 10
HI LO HI LO
OUT A OUT B
Cable Clamp
Figure 2-4
Routing wires through cable clamp
2-5
Card Connections and Installation
2.4
Typical connecting schemes
The following paragraphs discuss typical connections for the scanner card.
2.4.1 Thermocouple connections
Figure 2-5 shows typical thermocouple connections. Note that thermocouples are connected to channels 2-10, and output connections are taken from the OUT A terminals.
CH 10
OUT A
OUT B
CH 7
CH 8
CH 9
CH 2
CH 3
CH 4
CH 5
CH 6
2001-TCSCAN Card
Figure 2-5
Typical connections for thermocouple scanning
-
+
-
+
-
+
+
-
+
-
+
-
+
-
+
-
+
Thermocouples
Thermocouples
-
HI
LO
To DMM Input Jacks
2-6
Card Connections and Installation
2.4.2 Voltage connections
Figure 2-6 shows typical connections for voltage measurements. Note that up to nine voltage sources can be switched with this configuration. This basic configuration can be used for the following types of measurements:
• DCV
• ACV
• Frequency
Channels (2-10) can be used with this configuration.
CH 10
OUT A
OUT B
CH 7
CH 8
CH 9
CH 2
CH 3
CH 4
CH 5
CH 6
2001-TCSCAN Card
Figure 2-6
Connections for voltage scanning
V
HI
LO
V
HI
LO
HI
V
LO
V
HI
LO
HI
V
LO
Voltages
Under Test
V
HI
LO
HI
V
LO
HI
V
LO
HI
LO
V
HI
LO
To DMM Input Jacks
2-7
Card Connections and Installation
2.4.3 Resistance connections
■
2-Pole connections
Figure 2-7 shows typical 2-pole resistor test connections.
The 2-pole resistance configuration can be used to test up to seven DUTs.
NOTE
Channels 5 and 10 should not be used to switch 2-wire resistance measurements because of the relatively high path resistance (
≅
240
Ω
) of these two channels due to the factory-installed current-limiting resistors. (Unless the card is modified; see paragraph 4.8.)
■
4-Pole connections
Typical 4-pole resistance connections are shown in Figure 2-
8. This general configuration can be used with channel pairs
2-5 and 7-10 to scan:
• 4-wire resistance measurements.
• 4-wire RTD temperature measurements.
CH 10
OUT A
OUT B
CH 7
CH 8
CH 9
CH 2
CH 3
CH 4
CH 5
CH 6
2001-TCSCAN Card
Figure 2-7
Typical connections for 2-wire resistance scanning
Resistors
Under Test
HI
LO
To DMM Input Jacks
NOTE: Do not use channels 5 and 10 for 2-wire resistance measurements
2-8
Card Connections and Installation
CH 10
OUT A
OUT B
CH 7
CH 8
CH 9
CH 2
CH 3
CH 4
CH 5
CH 6
2001-TCSCAN Card
Figure 2-8
Typical connections for 4-wire resistance scanning
Resistors
Under Test
HI
LO
HI
LO
To DMM Input Jacks
To DMM Sense Jacks
2-9
Card Connections and Installation
2.5
Card installation and removal
This paragraph explains how to install and remove the Model
2001-TCSCAN card assembly from the DMM.
2.5.1 Scanner card installation
Perform the following steps and refer to Figure 2-9 to install the card assembly in the DMM:
WARNING
Installation or removal of the Model
2001-TCSCAN should be performed only by qualified service personnel.
Failure to recognize and observe standard safety precautions could result in personal injury or death.
WARNING
Turn off power to all instrumentation
(including the DMM), and disconnect all line cords. Make sure all power is removed and any stored energy in external circuitry is discharged.
CAUTION
To prevent contamination to the scanner card that could degrade performance, handle the card assembly only by the card edges and covers.
NOTE
Wiring connections must made before installing the scanner card. See paragraph
2.4 for wiring details.
1. Remove the cover plate from the OPTION SLOT on the rear panel of the DMM. To do so, pry out the two fasteners, then remove the cover plate.
2. Slide the card edges into the guide rails inside the multimeter (solder side up).
3. With the ejector arms in the unlocked position, carefully push the card all the way forward until the arms engage the ejector clips. Push both arms inward to lock the card into the multimeter.
4. After installation, connect the output leads to the multimeter as discussed below.
2-10
Unlock card
Ejector Arms (2)
Figure 2-9
Card installation
Lock card
WARNING: Installation or removal
should be performed only
by qualified service personel.
Card Connections and Installation
2-11
Card Connections and Installation
2.5.2 Output connections to multimeter
After installation, connect the scanner card output leads to the DMM rear panel jacks as follows:
• For 2-pole operation, connect OUT A HI (red) to IN-
PUT HI, and connect OUT A LO (black) to INPUT LO.
See Figure 2-10.
• For 4-pole operation, connect OUT A HI (red) to IN-
PUT HI, and connect OUT A LO (black) to INPUT LO.
Also connect OUT B HI (red) to SENSE HI, and connect OUT B LO (black) to SENSE LO. See Figure 2-11.
2.5.3 Scanner card removal
Follow the steps below to remove the scanner card from the multimeter:
WARNING
Turn off power to all instrumentation
(including the DMM) and disconnect all line cords. Make sure all power is removed and any stored energy in external circuitry is discharged.
NOTE
Be sure to select the rear inputs with the
DMM front panel INPUTS switch when using the scanner.
1. Unlock the card by pulling the latches outward.
2. Carefully slide the card out of the multimeter.
3. If the multimeter is to be operated without a scanner card installed, install the cover plate over the OPTION
SLOT.
2-12
Input HI
Out A
HI (Red)
Use this configuration
for : DCV
ACV
2-wire
Ω
2-wire RTD
Frequency
Thermocouple
A. Models 2001 and 2002
Input LO
Out A
LO (Black)
Card Connections and Installation
Input HI
Input LO
Out A
LO (Black)
Use this configuration
for : DCV
ACV
2-wire
Ω
2-wire RTD (Model 2010)
Thermocouple
B. Models 2000 and 2010
Figure 2-10
2-pole output connections
Out A
HI (Red)
2-13
Card Connections and Installation
Input HI
Input LO
Sense HI
Out A
HI (Red)
Out B
HI (Red)
Use this configuration for : 4-wire ohms
4-wire RTD
Sense LO
Out A
LO (Black)
Out B
LO (Black)
A. Models 2001 and 2002
Sense HI
Input HI
Sense LO
Out B
HI (Red)
Out B
LO (Black)
Input LO
Use this configuration for : 4-wire ohms
4-wire RTD (Model 2010)
Out A
LO (Black)
Out A
HI (Red)
B. Models 2000 and 2010
Figure 2-11
4-pole output connections
2-14
Operation
3.1
Introduction
This section contains detailed information on front panel and
IEEE-488 bus operation of the Model 2001-TCSCAN. The information in this section is organized as follows:
3.2
Signal limitations:
Summarizes the maximum signals that can be applied to the Model 2001-TCSCAN.
3.3
Scanner card detection:
Discusses how the scanner card is detected and how to determine whether or not the card is installed with a bus command.
Models 2001 and 2002 operation:
3.4
Front panel scanner controls:
Gives an overview of the Models 2001 and 2002 Multimeter front panel controls used to control the scanner card.
3.5
IEEE-488 bus scanner commands:
Summarizes bus commands necessary to control the scanner card.
3.6
Opening and closing channels:
Covers the basic methods for closing and opening channels.
3.7
Scanning channels:
Details how to configure scan parameters and how to perform scanning.
3.8
Temperature measurements:
Describes using the scanner card to make temperature measurements using themocouples and RTD probes.
Models 2000 and 2010 operation
:
3.9
Basic front panel operation:
Explains how to use the
Models 2000 and 2010 to perform basic scanner card operations using the Model 2001-TCSCAN card.
3.10 Temperature measurements:
Explains how to use the scanner card with the Models 2000 and 2010 to make temperature measurements.
3.11 Remote operation:
Summarizes the SCPI commands necessary to control the scanner card and make temperature measurements.
Models 2000, 2001, 2002, and 2010
:
3.12 Typical applications:
Discusses typical applications for the Model 2001-TCSCAN.
3.13 Measurement considerations:
Discusses a number of measurement considerations that should be taken into account when using the scanner.
NOTE
Before using the Model 2001-TCSCAN scanner card, you should be thoroughly familiar with the operation of the Model
2001 Multimeter. See the Model 2001 Operator’s Manual for details.
3-1
3.2
Signal limitations
CAUTION
To prevent damage to the Model 2001-
TCSCAN, do not exceed the maximum signal level specifications of the card.
To prevent over-heating or damage to the relays, never exceed the following maximum input signal levels:
DC signals: 110V DC, 1A switched, 30VA (resistive load).
1
AC signals: 125V rms or 175V AC peak, 1A switched,
62.5VA (resistive load). (Channels 5 and 10 maximum power = 0.25VA due to factory installed current-limiting resistors. See paragraph 4.8 for modification.)
3.3
Scanner card detection
3.3.1
Power-up detection
The scanner card is detected only at power-on. If the card is plugged into the DMM after the power is turned on, the card will not be recognized as being present by the DMM.
CAUTION
Plugging in the scanner card with power turned on may result in damage to both the Model 2001-TCSCAN and the
DMM.
If the card is not present at power-on, scanner bus commands or queries will generate a “Missing hardware error”, and front panel operations pertaining to the scanner will inform you that no scanner is present.
Refer to the individual DMM operator’s manual for more details on using the *OPT? query.
3.4
Front panel scanner controls
NOTE
Use paragraphs 3.4 through 3.8 for scanner card operation using the Models 2001 and 2002 DMMs. Models 2000 and 2010
DMM operation is covered in paragraphs
3.9 through 3.11.
The following paragraphs give an overview of the various
Model 2001 Multimeter controls used with the scanner.
Figure 3-1 shows the front panel of the Models 2001 and
2002. Controls that affect Model 2001-TCSCAN operation include:
• CHAN: Allows you to open and close channels directly.
• CONFIG-CHAN: Defines the measurement functions for each scanner channel.
• CONFIG-SCAN: Selects internal/external scan list.
• SCAN: Enters scan configuration menu.
• and : Manually scans through channels.
• TEMP: Enables temperature measurements.
• CONFIG-TEMP: Selects sensor type, thermocouple type, and reference junctions.
3.3.2
Scanner option bus query
*OPT? is an IEEE 488.2 common query which will allow you determine whether or not the Model 2001-TCSCAN card is installed. The response to this query has two fields.
The first field identifies the presence or absence of expansion memory, and the second field indicates whether or not the scanner is present as follows:
• 0: Scanner not installed.
• 2001-SCAN: Model 2001-TCSCAN scanner card installed.
3.4.1
Open and close channels (CHAN)
The CHAN key allows you directly:
• Open any closed channel(s) immediately.
• Close a specific channel (or channel pair for 4-wire functions).
Pressing CHAN will display the following menu choices:
CHANNEL SELECTION
CLOSE-CHANNEL OPEN-ALL-CHANNELS
3-2
PREV
DISPLAY
NEXT
POWER
ERR REM TALK LSTN SRQ REAR REL FILT MATH 4W AUTO ARM TRIG SMPL
DCV ACV DCI ACI
Ω
2
Ω
4
REL TRIG
INFO LOCAL
STORE RECALL FILTER MATH
CHAN SCAN CONFIG MENU
FREQ TEMP
EXIT ENTER
RANGE
AUTO
RANGE
SENSE
Ω
4 WIRE
HI
INPUT
350V
PEAK
!
1100V
PEAK
INPUTS
F R
FRONT/REAR
LO
2A 250V
AMPS
CAL
500V
PEAK
CHAN
• Close channel
• Open channel
SCAN
• Scan configuration
CONFIG-CHAN
• Define internal channel functions
• Define external channel functions
• Define alternate function
CONFIG-SCAN
• Select internal scan list
• Select external scan list
TEMP
• Enable temperature measurements
CONFIG-TEMP
• Select sensor type
• Choose thermocouple type
• Define reference junction
• Manually scan channels
EXIT
• Disable scanning
Figure 3-1
Models 2001 and 2002 front panel scanner controls
■
OPEN-ALL-CHANNELS
Selecting OPEN-ALL-CHANNELS will immediately open any closed scanner card channel(s).
■
CLOSE-CHANNELS
Selecting CLOSE-CHANNEL will display the following message prompting you to select the channel to close:
ENTER CHAN#01 (1-10)
The field entry after “ENTER CHAN#” indicates the channel to close. To close a channel, simply use the cursor and range keys to select the number of the channel to close, then press ENTER. The number of the closed channel will be displayed on the front panel along with normal readings. Keep in mind that channel 1 is the reference junction.
Selecting a different channel from the one that is presently closed will cause the closed channel to open and allow a settling time before closing the selected channel.
Channel relays will be closed according to the presently selected function. If a 2-wire function is used, only the relay for that one channel will be closed. If a 4-wire function is selected, both the selected channel relay and the matching relay pair will close. For example, closing channel 2 will also close the channel 7 relay. Fixed 4-pole relay pairs are:
• 2 and 7
• 3 and 8
• 4 and 8
• 5 and 10.
3-3
3.4.2
Configure channels (CONFIG-CHAN)
CONFIG-CHAN allows you to:
• Select measurement functions for internal (Model
2001-TCSCAN) channels.
• Select measurement functions for channels in an external scanner used with the Model 2001/2002.
• Define an alternate measurement function which can then be assigned to specific channels.
corresponding paired channel 7-10. Once
Ω
4W is selected on channels 2 to 5, changing the assignment to a different function will de-assign the paired channel and change the function to “---” (none).
CAUTION
Four-wire functions should not be used with channels 1 and 6.
Pressing CONFIG then CHAN will display the following menu:
CONFIGURE CHANNELS
INTERNAL-CHANS EXTERNAL-INPUTS
SAVE-ALT-FCN RESTORE-ALT-FCN
TMP function:
Similarly, the TMP selection is valid only for channels 2-5 if the RTD temperature sensor is a 4-wire type. If a 2-wire RTD type is used, channels 6-10 could be assigned to the TMP function, but if the sensor type is later change to 4-wire RTD, any channel from 6-10 will then be set to “---” (none). Thermocouple TMP measurements can be assigned to channels 2-10.
■
INTERNAL-CHANS
The INTERNAL-CHANS selection allows you to set the measuring function for each of the Model 2001-SCAN channels while scanning. When this selection is made, the following submenu will be displayed:
SET INTERNAL CHANS
1=DCV 2=DCV 3=DCV 4=DCV 5=DCV
6=DCV 7=DCV 8=DCV 9=DCV 10=DCV
No function (---):
Selecting none (---) effectively removes that channel from the scan list. When scanning, the instrument will skip any channels that have no function defined.
JN functions:
JN1 through JN5 are used to assign a reference junction to a channel. With the Model 2001-TCSCAN, the reference junction must be assigned to channel 1.
With this menu displayed, use the cursor keys to select the channel, and use the up arrow and down arrow (range) keys to select the desired measuring function for each channel:
DCV: DC volts
ACV: AC volts
Ω
2W: 2-wire ohms
Ω
4W: 4-wire ohms
FRQ: frequency
TMP: temperature
ALT: alternate function (see below)
JN1 – JN5: Reference junctions
--- : None
Ω
4W function:
The
Ω
4W function is valid only for channels 2-5. If selected, “PRD” (paired) will be shown on the
■
EXTERNAL-INPUTS
This menu item allows you to select measurement functions for an external scanner used with the Model 2001/2002 Multimeter. See the Model 2001/2002 Operator’s Manual for details.
■
SAVE-ALT-FCN/RESTORE-ALT-FCN
An ALT (alternate) function is one that cannot be directly accessed with one of the eight function keys. For example, assume that you select the ACV peak function using CONFIG-
ACV. You can then use SAVE-ALT to assign peak ACV to the ALT function. Whenever the ALT function is encountered in the scan list, the instrument will switch to the ACV peak function for that channel even if the instrument is measuring a different type of ACV (RMS for example).
You can also use the ALT function to store an existing main function but with a different set of operating parameters. For
3-4
example, you could set up thermocouple operating parameters for the TMP function and RTD setup parameters as the
ALT function. This arrangement allows you to specify changes in virtually any measurement parameter from channel to channel even if the measurement functions are the same.
3.4.4
Using SCAN to configure scan parameters and start scanning
Once the internal or external scan list is enabled, use the
SCAN key to configure scan count, scan interval, and enable buffer storage. The steps below outline the basic procedure for using the SCAN key to configure internal scanner operation.
SAVE-ALT-FCN:
Stores the presently selected function and all its configured settings as the ALT function.
RESTORE-ALT-FCN:
Restores the function that was saved as the ALT function and all associated settings as if a normal function change were taking place.
3.4.3
Scan configuration (CONFIG-SCAN)
CONFIG-SCAN allows you to select the internal or external channel list for scanning.
Pressing CONFIG-SCAN will display the following menu:
SCAN OPERATION
INTERNAL EXTERNAL RATIO DELTA
These choices select the action the instrument will take when it is triggered.
■
INTERNAL
This selection enables scanning with the internal Model
2001- TCSCAN scanner card.
■
EXTERNAL
This menu selection enables scanning with an external scanner card located in a switching mainframe. This selection operates in a manner similar to INTERNAL except that the internal scanner card is not used.
■
RATIO/DELTA
RATIO and DELTA should not be used with the Model
2001-TCSCAN. These selections are intended for use with a different scanner card.
1. From normal display, press CONFIG-SCAN. The instrument will display the following:
SCAN OPERATION
INTERNAL EXTERNAL RATIO DELTA
2. Select INTERNAL, then press ENTER.
3. Press SCAN. The unit will display the following message:
SCAN COUNT = 00010
4. Using the range and cursor keys, select the number of scan sequences, then press ENTER. The instrument will display the following:
USE SCAN TIMER?
YES NO
5. If you do not wish to use the scan timer (interval between scans), select NO, then press ENTER, and go on to step 7. If you wish to use and program the interval between scans, select YES, then press ENTER. The instrument will display the following:
INTRVL = 000002.500
6. Using the range and cursor keys, select the desired interval (in seconds) between scan sequences, then press EN-
TER.
7. The instrument will then prompt you as to whether or not you wish to store data in the buffer as follows:
DATA TO MEMORY?
YES NO
8. To store scanned data in the buffer, select YES; otherwise choose NO, then press ENTER.
3-5
9. If you elected to store data in memory, the instrument will prompt you as follows:
00100 RDGS TO BUFFER
Press ENTER to continue.
NOTE
Use CONFIG-STORE to program the number of readings to store.
3.4.5
Using EXIT to stop scanning
To disable scanning while in progress, press the EXIT key.
3.4.6
Manual scanning
The and keys can be used to manually scan through channels. In order to use this feature, first close a channel using the CHAN key. Use to increment channels, or use to decrement channels. To view adjacent channels simultaneously, turn on the multiple displays with the NEXT key.
10. Press ENTER to begin scanning at the following prompt:
Press ENTER to begin
0010 scans of 10 channels
11. The instrument will then scan using selected scanning parameters. If you elected to store data in memory, the instrument will display the reading number on the bottom line of the display as readings are stored.
12. After readings are stored, the following will be displayed:
SCAN COMPLETE
RECALL-DATA SCAN-AGAIN EXIT
13. Select the desired operation, then press ENTER.
3.5
IEEE-488 bus scanner commands
Table 3-1 summarizes commands that are typically used for scanning and temperature measurements over the IEEE-488 bus. Note that the query form for most of the listed commands is not included. For more information on these and other bus commands, refer to the Model 2001 or 2002 User’s
Manual.
Programming examples in paragraphs 3.6, 3.7, and 3.8.4 are provided using both HP BASIC and QuickBASIC 4.5 languages. The QuickBASIC examples use the HP-style Universal Language Driver (CECHP).
3-6
Table 3-1
Summary of SCPI commands (Models 2001 and 2002 )
Command Description
FORMat command summary
:FORMat
:ELEMents <item list>
Command to specify data elements to send over the bus:
Specify data elements (READing, CHANnel, RNUMber, UNITs,
TIMEstamp, STATus).
ROUTe command summary
:ROUTe
:CLOSe <list>
:STATe?
:CLOSe? <list>
:OPEN <list>|ALL
:ALL
:OPEN? <list>
:SCAN
[:INTernal] <list>
:FUNCtion <list>, <function>
:LSELect <name>
SENSe command summary
[:SENSe[1]]
:FUNCtion <name>
:ALTernate [1]
:SAVe
:RECall
Commands to control 2001-TCSCAN:
Close specified channels.
Query closed channels.
Query specified channels (1=closed, 0=open).
Open specified channels or all channels.
Open all channels.
Query specified channels (1=open, 0=closed).
Path to scan channels.
Configure internal scan list.
Assign function to specified channels (see NOTE at end of table).
Select scan list (INTernal, NONE).
Commands to configure measurements:
Select function (‘TEMPerature’, ‘VOLTage:AC’, ‘VOLTage:DC’,
‘RESistance’, ‘FRESistance’, ‘FREQuency’).
Program alternate function.
Save alternate function.
Recall alternate function.
:TEMPerature
:TRANsducer <name>
:RTD
:TYPE <name>
:RZERo <NRf>
:ALPHa <NRf>
:BETA <NRf>
:DELTa <NRf>
:TCouple
:TYPE <name>
:RJUNctionX
:RSELect <name>
:SIMulated <n>
:REAL
:TCOefficient <n>
:OFFSet <n>
:ACQuire
Path to configure temperature measurements:
Select transducer (RTD, FRTD, or TCouple).
Configure RTD temperature measurements:
Select RTD sensor type (PT100, D100, F100, PT3916, PT385 or USER).
Specify constant for USER type (0 to 1000).
Specify constant for USER type (0 to 0.01).
Specify constant for USER type (0 to 1.00).
Specify constant for USER type (0 to 5.00).
Configure thermocouple sensor.
Select thermocouple type (J,K,T,E,R,S, or B).
Configure reference junction; where X=1 for Model
2001-TCSCAN.
Select reference type (SIMulated or REAL).
Specify simulated temperature in˚C (0 to 50).
Configure real reference junction:
Specify temp coefficient (-0.09999 to 0.09999).
Specify voltage coefficient at 0˚C (-0.09999 to 0.09999).
Update reference temperature.
3-7
Table 3-1 cont.
Summary of SCPI commands (Models 2001 and 2002)
Command Description
TRACe command summary
:TRACe
:POINts <n>
:AUTO <b>
:FEED <name>
:CONTrol <name>
:DATA?
Trigger command summary
:INITiate
[:IMMediate]
:CONTinuous <b>
Commands to configure buffer:
Specify buffer size.
Enable or disable auto buffer sizing (uses :trigger:count).
Select source of readings (SENSe[1], CALCulate [1], NONE).
Select buffer control mode (NEVer, NEXT, ALWays).
Read all readings in the buffer.
Initiation commands:
Initiate one trigger cycle.
Enable or disable continuous initiation.
:TRIGger
:COUNt <n>
:SOURce <name>
:TIMer <n>
UNITs command summary
Trigger layer commands:
Specify total number of channels to scan (1 to 99999).
Select control source (IMMediate, TIMer, MANual).
Set timer interval (0 to 999999.999 seconds).
:UNIT
:TEMPerature <name>
Command to select temperature units:
Select temperature measurement units (C, CEL, F, FAR, K).
NOTE:
The SCAN:INTernal <function> parameter (ROUTe command summary) is one of the following:
VOLTage:DC DC volts
VOLTage:AC
TEMPerature
AC volts
Temperature
FREQuency
RESistance
FRESistance
RJUNctionX
NONE
ALTernate[1]
Frequency
2-wire ohms
4-wire ohms
Reference junction (X = 1 to 5)
No function (skips listed channel during scan).
Alternate function.
3-8
3.6
Closing and opening channels
Individual scanner card channels are closed and opened using the CHAN key. The following paragraphs discuss closing and opening channels from the front panel as well as with bus commands.
3.6.1
Closing channels
■
Front panel
Use the front panel CHAN key to close specific channels as follows:
1. From normal display, press the CHAN key. The instrument will display the following menu:
CHANNEL SELECTION
CLOSE-CHANNEL OPEN-ALL-CHANNELS
2. Select CLOSE-CHANNEL, then press ENTER. The
Model 2001 will display the following prompt:
ENTER CHANNEL# 01 (1-10)
3. Use the cursor and range keys to select the channel you wish to close (1-10), then press ENTER. Any previously closed channel will open, and the selected channel will close.
NOTE
Once a channel is closed, use the or key to manually scan through channels. Also, you can use the NEXT display to view three successive channels simultaneously.
■
IEEE-488 bus
Use the :ROUT:CLOSE command to close the desired channel. For example, either of the following program statements could be used to close channel 3.
HP BASIC
OUTPUT 716; “:rout:close (@3)”
QuickBASIC 4.5
PRINT #1, “output 16; :rout:close (@3)”
3.6.2
Opening channels
■
Front panel
Use the front panel CHAN key to open any closed channels as follows:
1. Press the CHAN key. The instrument will display the following menu:
CHANNEL SELECTION
CLOSE-CHANNEL OPEN-ALL-CHANNELS
2. Select OPEN-ALL-CHANNELS, then press ENTER.
The closed channel will open immediately.
■
IEEE-488 bus
Use the :ROUT:OPEN command to open the closed channel.
For example, either of the following program statements could be used to open channel 3:
HP BASIC
OUTPUT 716; “:rout:open (@3)”
QuickBASIC 4.5
PRINT #1, “output 16; :rout:open (@3)”
(You can also use :ROUT:OPEN:ALL or :ROUT:OPEN ALL to open channels.)
3.7
Scanning channels
Channels are scanned by configuring channels and programming the Model 2001/2002 to perform a scan. The following paragraphs outline step-by-step procedures for performing basic scanning from the front panel and over the IEEE-488 bus.
3.7.1
Front panel scanning
Step 1: Configure channels
Use CONFIG-CHAN to select the measurement functions for each of the scanner channels as follows:
1. Press CONFIG-CHAN. The instrument will display the following menu:
CONFIGURE CHANNELS
INTERNAL-CHANS EXTERNAL-INPUTS
3-9
2. Select INTERNAL-CHANS, then press ENTER. The multimeter will display the following menu:
SET INTERNAL CHANS
1=DCV 2=DCV 3=DCV 4=DCV 5=DCV
3. Using the cursor keys, select the desired channel (press the right cursor key to display channels 6 through 10).
4. Using the range keys, select the desired measurement function: DCV, ACV,
Ω
2W,
Ω
4W, FRQ, TMP, JN1-
JN5, ALT, --- (None).
5. Repeat steps 3 and 4 for each of the channels you wish to scan. NOTE: Select --- (none) to omit a channel from the scan list.
6. After selecting all measurement functions, press ENTER.
7. Press EXIT to return to normal display.
Step 2: Configure and start scan
Configure the scan as follows:
1. Press CONFIG-SCAN. The Model 2001/2002 will display the following:
SCAN OPERATION
INTERNAL EXTERNAL RATIO DELTA
2. Select INTERNAL, then press ENTER.
3. Press SCAN, and follow the prompts to configure scanning. See paragraph 3.4.4 for details.
3.7.2
IEEE-488 bus scanning
Step 1: Program channel functions
Use :ROUT:SCAN:INT:FUNC to program functions for the selected channels. For example, assume that you want to measure DC volts on channel 2, AC volts on channel 3, and
2-wire resistance on channel 6. The commands are as follows:
HP BASIC
OUTPUT 716; “:rout:scan:int:func (@2), ‘volt:dc’”
OUTPUT 716; “:rout:scan:int:func (@3), ‘volt:ac’”
OUTPUT 716; “:rout:scan:int:func (@6), ‘res’”
QuickBASIC 4.5
PRINT #1, “output 16; :rout:scan:int:func (@2), ‘volt:dc’”
PRINT #1, “output 16; :rout:scan:int:func (@3), ‘volt:ac’”
PRINT #1, “output 16; :rout:scan:int:func (@6), ‘res’”
If you wish to use the same function (for example DCV) on all three channels, either of the following commands can be used:
HP BASIC
OUTPUT 716; “:rout:scan:int:func (@2,3,6), ‘volt:dc’”
QuickBASIC 4.5
PRINT #1, “output 16; :rout:scan: int:func (@2,3,6),volt:dc’”
Step 2: Program internal scan list and start scan
Use the :ROUT:SCAN:INT command to program a scan list
(channels you wish to scan). For example, assume that you wish to scan channels 2, 3, and 6. This scan list can be programmed using either of the following commands:
HP BASIC
OUTPUT 716; “:rout:scan:int (@ 2,3,6)”
QuickBASIC 4.5
PRINT #1, “output 16; :rout:scan:int (@2,3,6)”
Scanning will begin immediately when this command is sent.
To disable scanning, send the :ROUT:SCAN:LSEL NONE command:
HP BASIC
OUTPUT 716; “:rout:scan:lsel none”
QuickBASIC 4.5
PRINT #1, “output 16; :rout:scan:lsel none”
3-10
3.8
Temperature measurements
The following paragraphs discuss using the Model 2001-
TCSCAN for making temperature measurements using thermocouples and RTD probes.
3.8.1
Thermocouple temperature measurements
The Model 2001-TCSCAN can be used to make temperature measurements with the following thermocouple types: J, K,
T, E, R, S, B. Measurements can be made either by automatic scanning, or by manually closing specific channels. The following paragraphs outline the procedures for making thermocouple temperature measurements using both of these methods. For more detailed information on temperature measurements in general, refer to the Model 2001/2002 Operator’s manual.
■ Thermocouple scanning
Follow the steps below to automatically scan through thermocouples and make temperature measurements.
Step 1: Connect thermocouples
Connect your thermocouples to the scanner input connectors using the general scheme shown in Figure 2-5 in Section 2.
4. Choose THERMOCOUPLE-TYPE, then press ENTER.
The list of supported thermocouple types will be displayed:
THERMOCOUPLE TYPE
J K T E R S B
5. Select the thermocouple type to match those you are using, then press ENTER. Select REF-JUNCTIONS on the displayed menu, then press ENTER. The Model
2001 will display the following:
CONFIGURE REFJCNS
JCN1 JCN2 JCN3 JCN4 JCN5
6. Select the desired reference junction (for example,
JCN1), then press ENTER. The instrument will display the following message:
REFERENCE JUNCTION#1
CONFIGURE ACQUIRE-REF-TEMP
7. Select CONFIGURE, then press ENTER. The following will be displayed:
CONFIGURE REFJCN#1
SIMULATED-TEMP REAL-JUNCTION
8. Select REAL-JUNCTION, then press ENTER. The instrument will prompt you to enter the reference junction coefficient:
REFJCN#1=+00.20mV/
°
C
Step 2: Select thermocouple type and reference junction parameters
1. From normal display, press CONFIG-TEMP. The instrument will display the following:
CONFIG TEMPERATURE
SENSOR UNITS SPEED FILTER RESLN
2. Select SENSOR, then press ENTER. The following will be displayed:
TEMP SENSOR TYPE
4-WIRE-RTD RTD THERMOCOUPLE
3. Select THERMOCOUPLE, then press ENTER. The
Model 2001 will then display the thermocouple setup menu:
THERMOCOUPLE SETUP
THERMOCOUPLE-TYPE REF-JUNCTIONS
9. If necessary, set the displayed value to +200
µ
V/
°
C
(+0.20mV/
°
C), then press ENTER. The unit will then prompt you for the reference offset:
OFFSET1=+54.63mV@0
°
C
10. If necessary, set the offset to +54.63mV @ 0
°
C, then press ENTER.
11. Press EXIT as necessary to return to the CONFIG TEM-
PERATURE menu, then select your UNITS, SPEED,
FILTER, and RESLN, as required.
12. Press EXIT to return to normal display.
3-11
Step 3: Configure channels
1. Press CONFIG-CHAN, select INTERNAL-CHANS, then press ENTER. The display will appear as follows:
SET INTERNAL CHANS
1=DCV 2=DCV 3= DCV 4=DCV 5=DCV
2. Using the range and cursor keys, set the channel functions as follows:
Channel 1: JN1 (or JN2-JN5 if using those junctions)
Channels 2-10: TMP for thermocouple channels, --- for unused channels, or other valid function if used.
3. After setting all channel functions, press ENTER to return to normal display.
Step 4: Configure and scan channels
1. From normal display, press CONFIG-SCAN. The instrument will display the following:
SCAN OPERATION
INTERNAL EXTERNAL RATIO DELTA
2. Select INTERNAL, then press ENTER.
3. Press SCAN, then follow the prompts to begin scanning.
See paragraph 3.4.4 for details.
■ Manual temperature measurements
In addition to scanning through channels to make temperature measurements, you can also make such measurements manually. In order to do so, you must first acquire the reference junction temperature and then manually close or scan through thermocouple channels. Note that the reference junction acquisition process should be repeated often, particularly if the ambient temperature changes; otherwise, temperature reading accuracy will be reduced.
NOTE
If you attempt to measure thermocouple temperature before acquiring the reference junction, the front panel “ERR” annunciator will indicate that an error has occurred.
Step 1: Connect Thermocouples
Connect your thermocouples to the desired channels, as covered in Figure 2-5, Section 2.
Step 2: Acquire reference junction temperature
1. Press the TEMP key to place the instrument in the temperature measurement mode.
2. Press CHAN. The unit will display the following:
CHANNEL SELECTION
CLOSE-CHANNEL OPEN-ALL-CHANNELS
3. Select CLOSE-CHANNEL, then press ENTER. The display will appear as follows:
ENTER CHAN#01 (1-10)
4. If necessary, use the range and cursor keys to select channel 1 (reference junction channel), then press EN-
TER. The unit will return to normal display, and it should indicate that channel 1 is closed.
5. Press CONFIG-TEMP. The Model 2001/2002 will display the following message:
CONFIG TEMPERATURE
SENSOR UNITS SPEED FILTER RESOLN
6. Choose SENSOR, then press ENTER. The unit will display the sensor type menu:
TEMP SENSOR TYPE
4-WIRE-RTD RTD THERMOCOUPLE
7. Select THERMOCOUPLE, then press ENTER. The thermocouple setup menu will be displayed:
THERMOCOUPLE SETUP
THERMOCOUPLE-TYPE REF-JUNCTIONS
8. Select THERMOCOUPLE-TYPE, then press ENTER.
Select your thermocouple type as outlined above. Select
REF-JUNCTIONS, then press ENTER. The following will be displayed:
CONFIGURE REFJCNS
JCN1 JCN2 JCN3 JCN4 JCN5
3-12
9. Choose JCN1, then press ENTER. The selection menu below will be displayed:
REFERENCE JUNCTION#1
CONFIGURE ACQUIRE-REF-TEMP
10. Select ACQUIRE-REF-TEMP, then press ENTER. The reference junction temperature has now been acquired.
11. Press EXIT as necessary to return to the CONFIG TEM-
PERATURE menu, then select the UNITS, SPEED,
FILTER, and RESLN, as required.
12. Press EXIT to return to normal display after completing temperature configuration.
Step 3: Close channels and display temperature
Close the desired channel (2-10) to display the temperature for that channel. Use the CHAN key and CLOSE-CHAN-
NEL menu selection to close a specific channel. Once a channel is closed, you can manually scan through channels using the and keys. Keep in mind that the reference junction temperature should be acquired often to assure measurement accuracy, especially if the ambient temperature changes. Remember that the TEMP function must be selected, and channel 1 must be closed to acquire the reference junction temperature.
3.8.2
RTD temperature measurements
The following paragraphs outline the procedures for making temperature measurements from the front panel using the scanner. For more detailed information on temperature measurements in general, refer to the Model 2001/2002 Operator’s manual.
Do not use channels 5 and 10 for 2-wire probes because of the higher path resistance of these channels.
Step 2: Select sensor type and units
1. From normal display, press CONFIG-TEMP. The instrument will display the following:
CONFIG TEMPERATURE
SENSOR UNITS SPEED FILTER RESLN
2. Select SENSOR, then press ENTER. The following will be displayed:
TEMP SENSOR TYPE
RTD 4-WIRE-RTD THERMOCOUPLE
3. Select RTD or 4-WIRE-RTD as appropriate for the sensor type you are using, then press ENTER. The instrument will display the following:
SET RTD TYPE
PT385 PT3916 USER-RTD
4. Select the RTD type from among the displayed types, then press ENTER.
5. Select UNITS, then press ENTER. The unit will display the following selections:
SET TEMP UNITS
DEG-C DEG-F K
6. Choose the type of temperature units you desire to use:
°
C,
°
F, or K, then press ENTER.
7. Before exiting the temperature configuration menu, select speed, filter, and resolution operating modes, if desired.
8. Press EXIT to return to normal display.
Step 1: Connect RTD probes
Connect RTD probes to the scanner using the basic resistance connections outlined in Section 2. For 4-wire probes, pair the connections as follows:
• Channels 2 and 7: probe #1
• Channels 3 and 8: probe #2
• Channels 4 and 9: probe #3
• Channels 5 and 10: probe #4
Step 3: Configure channels
1. Press CONFIG-CHAN. The instrument will display the following:
CONFIGURE CHANNELS
INTERNAL-CHANS EXTERNAL-INPUTS
3-13
2. Select INTERNAL-CHANS. The Model 2001/2002 will display the following:
SET INTERNAL CHANS
1=DCV 2=DCV 3=DCV 4=DCV 5=DCV
3. Use the cursor and range keys to select channels and functions. Set the function type to TMP for all channels connected to RTD probes. Select --- (none) for channels with no connections.
4. Press ENTER to return to normal display.
Step 4: Configure scan and scan channels
1. From normal display, press CONFIG-SCAN. The instrument will display the following:
SCAN OPERATION
INTERNAL EXTERNAL RATIO DELTA
2. Select INTERNAL, then press ENTER.
3. Press SCAN, then follow the prompts. See paragraph
3.4.4 for details.
2. Select SENSOR, then press ENTER. The unit will display the following:
TEMP SENSOR TYPE
4-WIRE-RTD RTD THERMOCOUPLE
3. Select 4-WIRE-RTD or RTD as appropriate, then press
ENTER. The instrument will then prompt for RTD type:
SET RTD TYPE
PT385 PT3916 USER-RTD
4. Choose the appropriate RTD type, then press ENTER.
5. Choose the desired UNITS, SPEED, FILTER, and
RESLN for the RTD measurements.
6. Press EXIT to return to normal display.
7. Press TEMP to select the temperature function.
8. Press CONFIG-CHAN. The Model 2001/2002 will display the following:
CONFIGURE CHANNELS
INTERNAL-CHANS EXTERNAL-INPUTS
SAVE-ALT-FCN RESTORE-ALT-FCN
9. Select SAVE-ALT-FCN, then press ENTER. The unit will inform you that the temperature function has been saved as the alternate function:
TMP settings saved as the ALT function
10. Press EXIT to return to normal display.
3.8.3
Using RTD and thermocouple sensors together
RTD and thermocouple sensors can be used together with the scanner. To do so, setup the TMP function for one type of temperature sensor, and configure the ALT function for the other type of temperature sensor. In the example below, the thermocouple sensor type is assigned to the TMP function, and the
RTD temperature sensor is assigned to the ALT function.
Step 1: Connect temperature sensors
Connect your RTD probes and thermocouples to the scanner input connectors using the general scheme shown in Section
2. Be sure to use the appropriate 2-wire or 4-wire connections for the RTD probes. (Do not use channels 5 and 10 for
2-wire probes because of the higher path resistance of these two channels.)
Step 2: Assign RTD sensor type to the ALT function
1. From normal display, press CONFIG-TEMP. The model will display the following:
CONFIG TEMPERATURE
SENSOR UNITS SPEED FILTER RESLN
Step 3: Select thermocouple type and reference junction parameters
1. From normal display, press CONFIG-TEMP. The instrument will display the following:
CONFIG TEMPERATURE
SENSOR UNITS SPEED FILTER RESLN
2. Select SENSOR, then press ENTER. The unit will display the following:
TEMP SENSOR TYPE
4-WIRE-RTD RTD THERMOCOUPLE
3-14
3. Select THERMOCOUPLE, then press ENTER. The
Model 2001/2002 will then display the thermocouple setup menu:
THERMOCOUPLE SETUP
THERMOCOUPLE-TYPE REF-JUNCTIONS
4. Choose THERMOCOUPLE-TYPE, then press ENTER.
The list of supported thermocouple types will be displayed:
THERMOCOUPLE TYPE
J K T E R S B
5. Select the thermocouple type to match those you are using, then press ENTER. Select REF-JUNCTIONS on the displayed menu, then press ENTER. The Model
2001/2002 will display the following:
CONFIGURE REFJCNS
JCN1 JCN2 JCN3 JCN4 JCN5
6. Select the desired reference junction (for example,
JCN1), then press ENTER. The instrument will display the following message:
REFERENCE JUNCTION#1
CONFIGURE ACQUIRE-REF-TEMP
7. Select CONFIGURE, then press ENTER. The following will be displayed:
CONFIGURE REFJCN1
SIMULATED-TEMP REAL-JUNCTION
8. Select REAL-JUNCTION, then press ENTER. The instrument will prompt you to enter the reference junction coefficient:
REFJCN#1=+00.20mV/
°
C
9. If necessary, set the displayed value to +200
µ
V/
°
C
(+0.20mV/
°
C), then press ENTER. The unit will then prompt you for the reference offset:
REFJCN#1=+54.63mV@
°
C
10. If necessary, set the offset to +54.63mV @ 0
°
C, then press ENTER.
11. Press EXIT as necessary to return to the CONFIG TEM-
PERATURE menu, then select your UNITS, SPEED,
FILTER, and RESLN, as required.
12. Press EXIT to return to normal display.
Step 4: Configure channels
1. Press CONFIG-CHAN. The display will appear as follows:
SCAN OPERATION
1=DCV 2=DCV 3-DCV 4=DCV 5=DCV
2. Using the range and cursor keys, set the channel functions as follows:
Channel 1: JCN1 (or JCN2-JCN5 if using those junctions)
Channels 2-10: TMP for thermocouple channels, ALT for RTD channels, --- for unused channels, or other valid function if used.
3. After setting all channel functions, press ENTER to return to normal display.
Step 5: Configure and scan channels
1. From normal display, press CONFIG-SCAN. The instrument will display the following:
SCAN OPERATION
INTERNAL EXTERNAL RATIO DELTA
2. Select INTERNAL, then press ENTER.
3. Press SCAN, then follow the prompts to begin scanning.
See paragraph 3.4.4 for details.
3.8.4
IEEE-488 programming example (temperature measurements)
A programming example to scan channels is provided to demonstrate how to perform temperature measurements using the Model 2001-TCSCAN card.
3-15
The program is written in Microsoft QuickBASIC 4.5 using the Keithley KPC-488.2 (or Capital Equipment Corporation)
IEEE interface and the HP-style Universal Language Driver
(CECHP). Note that before the program can be run, the
Universal Language Driver must first be installed. To install the driver, enter cechp at the DOS prompt.
If the CECHP command is in your AUTOEXEC.BAT file, the driver will automatically be installed each time you turn on your computer.
■ Open drivers and set terminator
The following program statements are required at the beginning of the program. They open the driver files and set the input terminator for CRLF.
OPEN ‘‘ieee’’ FOR OUTPUT AS #1
OPEN ‘‘ieee’’ FOR INPUT AS #2
PRINT #1, ‘‘interm crlf’’
‘Comments
1 Returns the instrument to the *RST default conditions.
Selects the TEMP function.
2
3 through 5 Configures instrument for type K thermocouple temperature measurements using ˚F
6 units.
Selects the REAL reference junction type.
The *RST command (line 1) sets the real reference junction coefficient to 0.20m V/˚C
7 and 8 and sets the reference offest to 54.63mV @0˚C.
Selects channel 1 for the reference junction and channels 2 through 6 for temperature measurements.
9 through 11 Acquires the reference junction temperature
(channel 1).
■ Configure temperature measurements
After opening the drivers and setting the terminator, add the following program statements to configure the Model 2001/
2002 to make Type K thermocouple temperature measurements:
PRINT #1, ‘‘output 16; *rst’’
‘Comments
‘1
PRINT #1, ‘‘output 16; func ‘temp’’’ ‘2
PRINT #1, ‘‘output 16; temp:tran tc’’ ‘3
PRINT #1, ‘‘output 16; temp:tc:type k’’
PRINT #1, ‘‘output 16; unit:temp f’’
‘4
‘5
PRINT #1, ‘‘output 16; temp:rjun:rsel real’’ ‘6
PRINT #1, ‘‘output 16; rout:scan:func
(@1), ‘rjun1’’’
‘7
PRINT #1, ‘‘output 16; rout:scan:func
(@2:6), ‘temp’’’
PRINT #1, ‘‘output 16; rout:clos (@1)’’
PRINT #1, ‘‘output 16; temp:rjun1:acq’’
PRINT #1, ‘‘output 16; rout:open:all’’
‘8
‘9
‘10
‘11
■ Configure and perform automatic scanning
Add the following statements to the program to configure and perform two scans of five channels (2 through 6):
PRINT #1, ‘‘output 16; trig:coun 10’’
PRINT #1, ‘‘output 16; trig:sour tim’’
PRINT #1, ‘‘output 16; trig:tim 0.5’’
‘Comments
‘12
‘13
‘14
PRINT #1, ‘‘output 16; rout:scan (@2:6)’’ ‘15
PRINT #1, ‘‘output 16; rout:scan:lsel int’’ ‘16
PRINT #1, ‘‘output 16; trac:poin:auto on’’ ‘17
PRINT #1, ‘‘output 16; trac:feed sens’’ ‘18
PRINT #1, ‘‘output 16; trac:feed:cont next’’ ‘19
PRINT #1, ‘‘output 16; form:elem read, ‘20 chan, unit’’
PRINT #1, ‘‘output 16; init’’
PRINT #1, ‘‘output 16; trac:data?’’
PRINT #1, ‘‘enter 16’’
LINE INPUT #2, A$
PRINT A$
END
‘21
‘22
‘23
‘24
‘25
3-16
‘Comments
12
13 and 14
15
Sets trigger count to 10 (two scans of five channels).
Selects Timer and sets it for 0.5 seconds.
This is the delay period between scanned channels.
Configures the scan list for channels 1 through 6.
16 Selects internal scanning.
17 through 19 Configures buffer to store 10 temperature
20 readings.
Includes channel number and temperature
21 units with readings over the bus.
Starts scanning operation.
22 through 25 After the two scans are finished, the 10 temperature readings are sent to the computer where they are displayed.
■ Open and close channels
Manual scanning can be performed by using the following programming statements to open and close channels. The following statements assume that the previous scanning program has been run. Remember that the timer was set to
0.5 seconds. Therefore, once a temperature measurement channel is closed, the temperature readings will update at that rate.
NOTE
The reference junction temperature (channel 1) needs to be acquired often to assure accurate temperature measurements.
PRINT #1, ‘‘output 16; init:cont on’’
PRINT #1, ‘‘output 16; :rout:clos (@1)’’
PRINT #1, ‘‘output 16; temp:rjun1:acq’’
PRINT #1, ‘‘output 16; :rout:clos (@ 3)’’
PRINT #1, ‘‘output 16; :rout:open:all’’
‘Comments
‘1
‘2
‘3
‘4
‘5
‘Comments
1
2 and 3
4
5
Enables continuous initiation.
Closes channel 1 and acquires the reference junction temperature.
Opens channel 1 and closes channel 3. The temperature reading for channel 3 is displayed.
Opens channel 3.
3-17
3.9
Basic front panel operation
Paragraphs 3.9 through 3.11 provide information on scanner card operation using the Models 2000 and 2010 DMMs.
Models 2001 and 2002 DMM operation is covered in paragraph 3.4 through 3.8
Figure 3-2 shows the front panel of the Models 2000 and 2010.
Controls that affect Model 2001-TCSCAN operation include:
• and — Lets you manually step through consecutive internal card channels.
• OPEN and CLOSE — Lets you selectively open and close internal card channels.
• SHIFT-CONFIG — Use to configure stepping/scanning.
• STEP — Starts a stepping operation of consecutive channels, where the output triggers are sent after every channel closure.
• SCAN — Starts a scanning operation of consecutive channels, where an output trigger is sent at the end of the scan list.
• SHIFT-HALT — Stops stepping or scanning and restores the trigger model to a non-scanning mode.
3.9.1
Configure stepping and scanning
The SHIFT-CONFIG key combination lets you:
• Select the step/scan type (internal or external).
• Set the step/scan list length by specifying the first and last channels in the step/scan.
• Specify the time period between stepped channels and scans.
• Specify the number of readings to store in the buffer
(reading count).
Perform the following steps to configure stepping or scanning:
1. Press SHIFT and then CONFIG to access the step/scan configuration.
2. Select INTernal scan by using the and keys and pressing ENTER.
SHIFT TEMP
OPEN CLOSE
CONFIG HALT
STEP SCAN
OPEN and CLOSE
• Open channel
• Close channel
and
• Manually step through channels
STEP
• Start stepping
operation
SHIFT-CONFIG
• Select internal or external scanning
• Select first and last channels in the scan list
• Set time between stepped channels or scans
• Set number of readings to store in buffer
Figure 3-2
Models 2000 and 2010 front panel scanner controls
SCAN
• Start scanning operation
SHIFT-HALT
• Stop stepping or
scanning operation
TEMP
• Enable temperature
measurements
3-18
3. Set the step/scan list length:
• Select the first channel in the step/scan list (MINimum
CHANnel) by using the and keys and pressing
ENTER.
• Select the last channel in the step/scan list (MAXimum
CHANnel) and press ENTER. Step/scan list length =
(MAX CHAN - MIN CHAN) + 1.
4. The next selection configures the timer (this is the Timer control source in the trigger model). With the timer disabled (OFF), the time period between each stepped or scanned channel depends on how the trigger model Delay is configured.
When stepping, the Timer determines the time period between stepped channels. Note that if the trigger model
Delay period is larger than the Timer period, the Delay period will instead be in effect.
When scanning, the Timer determines the time period between scans. It has no effect on the time period between each scanned channel. For example, assume that the instrument is configured to perform two scans and the Timer is set for 10 minutes. The first scan will start when the SCAN key is pressed. The second scan will start 10 minutes after the completion of the first scan.
The time period between each scanned channel is determined by the trigger model Delay.
After enabling the timer (ON), the Model 2000/2010 prompts for a time period:
00H:00M:00.000S
Use the , , , and keys to select a time period and press ENTER.
5. Next, you are prompted for a reading count (RDG
CNT). The reading count determines how many channels are stepped/scanned and how many readings are stored in the buffer. This can be less than, equal to, or greater than the step/scan list length (up to 1024).
• Stepping — The reading count specifies the number of channels stepped. For example, assume the step list length is 10 and the reading count is 15. After stepping through the 10 channels, the stepping process wraps back to the first channel and continues until channel 5 is stepped. The readings for the 15 stepped channels are stored in the buffer.
• Scanning — The reading count determines the number of scans to be performed. If the reading count number is not a multiple of the scan list length, then an additional scan will be performed to accommodate the extra channel(s). For example, assume that the scan list length is 10 and the reading count is 25. Three scans will be performed to acquire the 25 readings. Even though 30 channels will be scanned, only 25 readings will be stored in the buffer.
6. Press ENTER to return to the normal display.
The present trigger model Delay setting may have an effect on time periods for stepping and scanning. When stepping, the trigger model Delay will be in effect if its time period is larger than the Timer period. Otherwise, the Timer determines the time delay between stepped channels. When scanning, the Delay determines the time period between scanned channels. Delay has no effect on the time between scans, which is determined by the Timer.
The trigger model Delay is set by pressing SHIFT and then
DELAY. With AUTO Delay selected, the nominal delay period is only long enough to let the relays settle. With MANual Delay selected, you can manually specify the Delay (up to 99H:99M:99.999S).
3.9.2
Open and close channels
and
keys — These keys can be used to manually scan through channels on the internal scanner card. With a scanner card installed in the option slot, press the key to manually increment channels, or the key to manually decrement channels. The annunciator of the closed channel is lit. Hold down either key to manually scan through channels continuously. Press OPEN to open all channels. Remember that channel 1 is the reference junction.
3-19
OPEN and CLOSE keys — These keys also control channels on the internal scanner card. The keys let you directly:
• Close a specific channel (or channel pair for 4-wire configuration).
• Immediately open any closed channel (or channel pair for 4-wire configuration).
With a scanner card installed in the option slot, the following prompt is displayed when the close key is pressed:
CLOSE CHAN:01
3.9.3
Start stepping or scanning
The STEP key is used to start the stepping process. When
STEPping, an output trigger is sent after each channel is closed. Stepping will stop after the last reading count (RDG
CNT) channel closes.
The SCAN key is used to start the scanning process. When
SCANning, an output trigger is sent at the end of the scan list. Thus, if 3 scans are performed, 3 output triggers will occur. The specified reading count (RDG CNT) determines the number of scans performed. The instrument will perform enough scans to accommodate the specified reading count
(RDG CNT). Scanning will stop after the last scan list channel (of the last scan) closes.
Use the , , , and keys to display the desired channel (1 to 10) and press ENTER. The annunciator of the closed channel will be displayed on the front panel along with normal readings. Selecting a different channel from the one presently closed will cause the closed channel to open and allow a settling time before closing the selected channel.
Remember that channel 1 is the reference junction.
NOTE
When finished, press SHIFT and then
HALT to exit from the STEP/SCAN mode.
Channel relays will be closed according to the presently selected function. If a 4-wire function is selected, both the selected channel relay and the matching pair relay will be closed. Valid 4-pole channel pairs are:
• 2 and 7
• 3 and 8
• 4 and 9
• 5 and 10
CAUTION
Do not use channel pair 1 and 6. Channel 1 is the temperature reference junction. Applying a signal to channel 6 could damage the reference junction.
3.10 Temperature measurements
The following paragraphs explain how to make temperature measurements from the front panel using the Model 2001-
TCSCAN installed in the Model 2000/2010. Measurements can be made by either automatic stepping/scanning or by manually closing specific channels. Sensors that can be used for temperature measurements include:
• Model 2000: Thermocouples types - J, K, or T
• Model 2010: Thermocouple types - J, K, T, or N
RTD types - PT100, USER, PT3916,
PT385, F100, or D100
NOTE
The Model 2000 can only use thermocouples to make temperature measurements.
Pressing OPEN will immediately open any closed scanner card channel or channel pair for a 4-wire function.
3-20
3.10.1 Temperature measurement configuration
Use the following menu structure to configure the Model
2000/2010 for temperature measurements.
Press SHIFT and then TEMP. The following choices are available using the and keys:
• UNITS — C, K, or F (Centigrade, Kelvin, Fahrenheit).
Use to select the displayed units for temperature measurements.
• SENSOR (Model 2010 only) — TCOUPLE or 4W-
RTD (sensor type). Use to select the sensor type for the
Model 2010.
• TYPE — Use to specify the sensor that you are using:
Model 2000 - J, K, or T (thermocouple type).
Model 2010 - J, K, T, or N (thermocouple type) or
PT100, USER, PT3916, PT385, F100 or D100 (4W-
RTD type).
• JUNC — SIM or CH1 (simulated or referenced to channel 1). Select CH1 to reference measurements to the reference junction of the Model 2001-TCSCAN card.
3.10.2 Temperature measurement procedure
Perform the following steps to perform temperature measurements:
Step 1: Connect sensors
Thermocouples — Connect the thermocouples to the scanner input connectors using the scheme shown in Figure 2-5 in Section 2.
RTDs (Model 2010 only) — If using RTD probes, connect them to the scanner using the basic resistance connection schemes provided in Section 2. For 4-wire probes, pair the connections as follows:
• Channels 2 and 7: probe #1
• Channels 3 and 8: probe #2
• Channels 4 and 9: probe #3
• Channels 5 and 10: probe #4
Step 2: Configure temperature measurements
As previously explained (see ‘‘Temperature measurement configuration’’), configure the Model 2000/2010 for temperature measurements.
Step 3: Configure stepping/scanning
As explained in paragraph 3.9, configure the Model 2000/
2010 for internal stepping/scanning. From the SHIFT/CON-
FIG menu structure, you can also modify the step/scan list, specify the time between stepped channels and scans, and set the reading count.
Step 4: Step or scan channels
Manual stepping — Use the and keys to manually step through channels on the Model 2001-TCSCAN card.
The OPEN and CLOSE keys can also be used to control channels. See ‘‘Open and close channels’’ in paragraph 3-9 for details on manually stepping through channels.
Automatic stepping/scanning — The STEP key is used to start automatic stepping, and the SCAN key is used to start automatic scanning. When STEPping, an output trigger is sent after each channel is closed. When SCANning, an output trigger is sent at the end of the scan list.
Step 5: Stop automatic stepping/scanning
When finished, exit from the stepping/scanning mode by pressing SHIFT and then HALT.
3.11 Remote operation
Tables 3-2 and 3-3 summarize commands typically used for scanning and temperature measurements over the IEEE-488 bus and the RS-232 Interface. The commands in Table 3-2 apply to both the Model 2000 and the Model 2010, while the additional commands for the TEMP function in Table 3-3 apply only to the Model 2010. For more detailed information on these and other bus commands, refer to the Model 2000 or 2010 User's Manual.
Do not use channels 5 and 10 for 2-wire probes because of the higher path resistance of these channels.
3-21
Summary of SCPI commands (Models 2000 and 2010)
Command
FORMat command summary
:FORMat
:ELEMents <item list>
ROUTe command summary
:ROUTe
:CLOSe <list>
:STATe?
:OPEN:ALL
:MULTiple
:CLOSe <list>
:STATe?
:OPEN <list>
:SCAN
[:INTernal] <list>
:LSELect <name>
SENSe command summary
[SENSe[1]]
:TEMPerature
:TCouple
:TYPE <name>
:RJUNction
:RSELect <name>
:SIMulated <n>
:REAL
:TCOefficient <n>
:OFFSet <n>
TRACe command summary
:TRACe
:POINts <NRf>
:FEED <name>
:CONTrol <name>
:DATA?
Trigger command summary
:INITiate
[:IMMediate]
:CONTinuous <b>
Command to specify data elements to send over the bus.
Specify data elements (READing, CHANnel, UNITs).
Commands to control scanner card:
Close specified channel (or channel pair).
Query closed channel (or channel pair).
Open all channels.
Path to close and open multiple channels:
Close specified channels.
Query closed channels.
Open specified channels.
Path to scan channels.
Configure internal scan list.
Select scan list (INTernal, EXTernal, or NONE) and start scan.
Sense subsystem.
Description
Path to configure temperature measurements:
Configure thermocouple sensor:
Select thermocouple type (J, K, T (also N for Model 2010)).
Configure reference junction:
Select reference type (SIMulated or REAL).
Specify simulated temperature in
°
C (0 to 50).
Configure real reference junction:
Specify temp coefficient (-0.09999 to 0.09999).
Specify voltage coefficient at 0
°
C (-0.09999 to 0.09999).
Commands to configure buffer:
Specify buffer size (2 to 1024).
Select source of readings (SENSe[1], CALCulate[1], NONE).
Select buffer control mode (NEVer or NEXT).
Read all readings in buffer.
Initiation commands:
Initiate one trigger cycle.
Enable or disable continuous initiation.
:TRIGger
:COUNt <n>
:DELay <n>
:AUTO <b>
:SOURce <name>
:TIMer <n>
UNITs command summary
:UNIT
:TEMPerature <name>
Trigger layer commands:
Specify total number of channels to scan (1 to 9999).
Set delay between scanned channels (0 to 999999.999 sec).
Enable or disable auto delay.
Select control source (IMMediate, TIMer, MANual, BUS, EXTernal).
Set timer interval (0 to 999999.999 sec).
Command to select temperature units:
Select temperature measurement units (C, F, or K).
3-22
Table 3-3
Additional SCPI commands for the Model 2010
Command Description
SENSe command summary:
[:SENSe[1]]
:TEMPerature
:TRANsducer <name>
:FRTD
:TYPE <name>
:RZERo <NRf>
:ALPHa <NRf>
:BETA <NRf>
:DELTa <NRf>
Commands to select transducer type and configure RTD
temperature measurements:
Select transducer type:
Configure RTD temperature measurements:
Select RTD sensor type (PT100, D100, F100, PT3916, PT385, or USER).
Specify constant for USER type (0 to 10000).
Specify constant for USER type (0 to 0.01).
Specify constant for USER type (0 to 1.00).
Specify constant for USER type (0 to 5.00).
3.11.1 IEEE-488 programming example
(temperature measurements)
The following programming example is provided to demonstrate how to perform temperature measurements using the
Model 2001-TCSCAN card.
It is written in Microsoft QuickBASIC 4.5 using the Keithley
KPC-488.2 (or Capital Equipment Corporation) IEEE interface and the HP-style Universal Language Driver (CECHP).
Note that before the programming example can be run, the
Universal Language Driver must first be installed. To install the driver from the DOS prompt, enter the cechp command.
If the CECHP command is in your AUTOEXEC.BAT file, the driver will automatically be installed each time you turn on your computer.
■ Open drivers and set terminator
The following program statements are required at the beginning of the program. They open the driver files and set the input terminator for CRLF.
OPEN ‘‘ieee’’ FOR OUTPUT AS #1
OPEN ‘‘ieee’’ FOR INPUT AS #2
PRINT #1, ‘‘interm crlf’’
■ Configure temperature measurements
After opening the drivers and setting the terminator, add the following program statements to configure the Model 2000/
2010 to make Type K thermocouple temperature measurements:
‘Comments
PRINT #1, ‘‘output 02; *rst’’ ‘1
PRINT #1, ‘‘output 02; func ‘temp’’’ ‘2
PRINT #1, ‘‘output 02; unit:temp f’’ ‘3
PRINT #1, ‘‘output 02; temp:tc:type k’’ ‘4
PRINT #1, ‘‘output 02; temp:tc:rjun:rsel real’’ ‘5
‘Comments
1 Returns the instrument to the *RST default
conditions. For the Model 2010, this
command selects the thermocouple trans
ducer type.
2 Selects the TEMP function.
3
4
Selects ˚F temperature measurement units.
Selects type K thermocouple.
5 Selects the REAL reference junction type.
The *RST command (line 1) sets the real
reference junction coefficient to 0.20mV/˚C
and sets the reference offset to 54.63mV @
0˚C.
3-23
■ Configure and perform automatic scanning
Remote scanning resembles front panel stepping rather than front panel scanning. For this reason, the front panel STEP annunciator is on for remote scanning.
• A trigger is output after every channel is scanned and measured.
• The time period between scanned channels can be set using the trigger model Timer or the trigger model Delay. When using the Timer, the larger of the time periods (Timer or Delay) is in effect for scanning.
Add the following statements to the program to configure and perform two scans of six channels.
NOTE
Channel 1 is included in the scan list because the reference junction temperature needs to be acquired to assure measurement accuracy for the temperature measurement channels (2 through 6).
‘Comments
PRINT #1, ‘‘output 02; init:cont off’’
PRINT #1, ‘‘output 02; trig:coun 12’’
PRINT #1, ‘‘output 02; trig:sour tim’’
‘6
‘7
‘8
PRINT #1, ‘‘output 02; trig:tim 0.5’’
PRINT #1, ‘‘output 02; rout:scan (@1:6)
‘9
‘10
PRINT #1, ‘‘output 02; rout:scan:lsel int’’ ‘11
PRINT #1, ‘‘output 02; trac:poin 12’’ ‘12
PRINT #1, ‘‘output 02; trac:feed sens’’ ‘13
PRINT #1, ‘‘output 02; trac:feed:cont next’’ ‘14
PRINT #1, ‘‘output 02; form:elem read, chan, unit’’
‘15
PRINT #1, ‘‘output 02; init’’
PRINT #1, ‘‘output 02; trac:data?
PRINT #1, ‘‘enter 02’’
LINE INPUT #2, A$
‘16
‘17
‘18
‘19
PRINT A$ ‘20
PRINT #1, ‘‘output 02; rout:scan:lsel none’’ ‘21
PRINT #1, ‘‘output 02; rout:open:all’’
END
‘22
‘Comments
6
7
8 and 9
Disables continuous intiation.
Sets trigger count to 12 (2 scans of 6 channels).
Selects TIMER and sets it for 0.5 seconds.
This is the delay period between scanned channels.
Configures the scan list for channels 1 10
11 through 6.
Selects internal scanning.
12 through 14 Configures buffer to store 12 temperature readings.
15 Includes channel number and temperature
units with readings over the bus.
16 Starts scanning operation.
17 through 20 After the 2 scans are finished, the 12
21
22 temperature readings are sent to the computer where they are displayed.
Disables the scanning mode of operation.
Opens the last scanned channel (6).
■ Open and close channels
Manual scanning can be performed by using the
:ROUTe:CLOSe/OPEN commands. The following programming statements used to measure temperature at channel 3 assume the instrument is already configured to make temperature measurements. The previous programming example configures the instrument to make type K thermocouple temperature measurements (˚F).
NOTE
Channel 1 (reference junction) needs to be read often to ensure accurate temperature measurements.
‘Comments
PRINT #1, ‘‘output 02; :rout:clos (@1)’’
PRINT #1, ‘‘output 02; :rout:clos (@ 3)’’
PRINT #1, ‘‘output 02; :rout:open:all’’
‘Comments
1
2
3
‘1
‘2
‘3
Closes channel 1 to acquire the reference junction temperature.
Opens channel 1 and closes channel 3. The temperature for channel 3 is displayed on the instrument.
Opens channel 3.
3-24
Note that when a four-wire function is selected (
Ω
4 or 4W-RTD for the Model 2010), closing a channel (1 through 5) will also close the paired channel. For example, if you close channel 2, channel 7 will also close.
CAUTION
With a 4-wire function selected, do not connect anything to channel 6. In the 4pole mode, channel 1 (which is the reference junction) is paired with channel 6. Therefore, when channel 1 is closed, channel 6 also closes. Applying a signal to channel 6 could damage the reference junction.
The ROUTe:MULTiple:CLOSe/OPEN commands can also be used to control scanner card channels. As the name implies, you can specify multiple channels to be closed at the same time. Note that channel 11 is the 2-pole/4-pole relay (see Figure 2-1). Closing channel 11 selects the 2-pole operating mode. With channel 11 open, the 4-pole mode is selected.
■
2-wire resistance tests
Figure 3-3 shows a typical test setup for making 2-wire resistance measurements. The Model 2001-TCSCAN card provides the switching function, while the resistance measurements are made by a DMM. Since only 2-pole switching is required for this application, one Model 2001-TCSCAN card can be used to switch up to seven resistors. Note, however, that the 240
Ω
on resistance of channels 5 and 10 may affect the measurement accuracy of 2-wire resistance measurements made using these channels. Generally, channels 5 and 10 should not be used for
2-wire resistance measurements unless the card is modified.
(See paragraph 4.8 in Section 4.)
Measurement accuracy can be optimized by minimizing residual resistance: make connecting wires as short as possible, and limit the number of connectors to minimize path resistance. Another technique is to short one of the scanner channel inputs, close the shorted channel, and then enable the multimeter REL feature to null out path resistance. Leave
REL enabled for the entire test.
CAUTION
When closing multiple channels, make sure that you do not inadvertently connect the reference junction (channel 1) to other channels. Applying a signal to a channel that is connected to channel 1 could damage the reference junction.
3.12 Typical applications
NOTE
The information in the following paragraphs pertains to the Models 2000, 2001,
2002, and 2010.
DMM
2001-TCSCAN
Input HI
Input LO
Out A
A. Test Configuration
2
9
2
3-4, 6-8
9
DUTs
(7)
Ω
R
3.12.1 Resistor testing
The Model 2001-TCSCAN can be used to test up to seven resistors using 2-wire measurements, or up to four resistors using 4-wire measurements. Such tests use the Model 2001
Ω
2 and
Ω
4 resistance functions.
DMM
2001-TCSCAN
B. Simplified Equivalent Circuit
Figure 3-3
2-wire resistance test connections
DUT
3-25
■
4-wire resistance tests
More precise measurements over a wider range of system and DUT conditions can be obtained by using the 4-wire measurement scheme shown in Figure 3-4. Here, separate sense leads from the DMM are routed through the scanner to the resistor under test. The extra set of sense leads minimizes the effects of voltage drops across the test leads, greatly reducing measurement errors with lower DUT resistances.
Note, however, that an extra two poles of switching are required for each resistor tested. For this reason, only four resistors can be tested using this configuration.
2001-TCSCAN
DMM
Input HI
Sense HI
Input LO
Sense LO
Out A
HI
Sense
HI
2
5
1
4
DUTs
(4)
LO
Sense
LO
Out B
7
10
A. Test Configuration
Figure 3-4
4-wire resistance test connections
3-26
HI
Sense HI
Ω
DMM
Sense LO
LO
2001-TCSCAN
B. Simplified Equivalent Circuit
DUT
R
DMM
Input HI
Input LO
Out A
HI
LO
2001-TCSCAN
CH 2
CH 3
CH 4
Sense HI
Sense LO
Out B
HI
LO
CH 5
CH 6
CH 7
CH 8
CH 9
CH 10
DUT's (6)
Figure 3-5
Combining 2-pole and 4-pole switching
■ Combining 2-pole and 4-pole switching
The Model 2001-TCSCAN can combine 2- and 4-pole switching in various combinations. For example, you might require 4-pole switching for only two resistors, while the remaining resistors could be tested using conventional 2-pole switching.
Figure 3-5 shows a test configuration using mixed 2-pole and
4-pole switching. Four-pole switching is used only for the device connected to channels 2 and 7. Five more resistors are tested using 2-pole switching. In order to use this configuration, configure the channels for
Ω
2 and
Ω
4 functions as appropriate.
3-27
3.12.2 Resistor temperature coefficient testing
Temperature coefficient is the rate of change of resistance with respect to temperature, typically expressed as ppm/
°
C
(parts per million per degree centrigrade).
For example, a resistor that measures exactly 100
Ω
at 25
°
C with a temperature coefficient of 100ppm/
°
C should not change more than 10m
Ω
per
°
C of temperature change. That resistor measured at 35
°
C should read between 99.900 and
100.100
Ω
(100
Ω±
100m
Ω
).
Temperature coefficient is calculated from the following equation:
TC =
( ∆
R
( )
)
(
(
10
∆
T
6
)
) where:
TC = temperature coefficient in ppm/
°
C
∆
R = change in resistance (reference resistance – test resistance)
R = actual resistance at the reference temperature
∆
T = change in temperature (reference temperature – test temperature)
Typically, several samples of a particular resistor from a vendor will be tested to verify the specifications. The temperature coefficient is usually checked at several temperature points to ensure its integrity over a range of temperatures.
Evaluation of resistors can be done with a Model 2001-TC-
SCAN card in a DMM to make temperature and 4-terminal resistance measurements. Temperature coefficients are calculated with respect to the resistance measurement made at a reference temperature. Thermal EMFs generated by connections in the test circuit are cancelled by the offset-compensated ohms feature of the DMM.
Figure 3-6 shows a system that can test accuracy and temperature coefficient of up to seven resistors that have the same specifications (resistance and temperature coefficient.)
The thermocouple is connected to channel 2, while a short is connected to channel 3 to allow for offset compensation. The
HI terminals of the resistors are connected to channels 3-10, while the LO terminals are connected to the DMM LO terminals.
3-28
DMM
Input HI
Sense HI
Sense LO
Input LO
Model 2001-TCSCAN
1
REF
JCN
2
A. Test Configuration
3
4 - 10
Short
Source HI
Sense HI
Sense LO
Source LO
Thermocouple
DUT
t
°
DMM
2001-TCSCAN
TC
Ω
DMM DUT
B. Simplified Equivalent Circuit
Figure 3-6
Resistor temperature coefficient testing
2001-TCSCAN
R
DUT
3-29
3.13 Measurement considerations
Many measurements made with the DMM are subject to various effects that can seriously affect low-level measurement accuracy. The following paragraphs discuss these effects and ways to minimize them.
channels. Adjacent channels will have no more than the following gradient between them:
• Channels 2–6: 0.05
°
C
• Channels 7–10: 0.07
°
C
3.13.1 Thermocouple measurement error sources
The temperature measurement accuracy specification of the
Model 2001-TCSCAN is the sum of the following error sources:
• Reference junction sensor error
• Temperature gradient across the card
• Relay offset voltage
• DMM measurement accuracy
• DMM temperature conversion algorithm
■ Relay offset voltage
The primary source of offset voltage is the contact potential of the relay, typically <500nV. Channels 2–4, 6–9 have the lowest offset (1
µ
V worst case), and channels 5 and 10 have a somewhat higher offset (<2
µ
V). For a type K thermocouple, 1
µ
V offset produces 0.024
°
C of error.
■ Measurement accuracy
The voltage measurement accuracy and temperature conversion algorithm determine the accuracy of the instrument. The
DMM has these parameters combined with scanner card errors. For type K thermocouples, the DMM has 0.7
°
C accuracy. The Model 2001-TCSCAN card is responsible for no more than 0.48
°
C of these errors.
You can achieve better card performance by understanding how these error sources contribute to the specification.
■ Temperature conversion algorithm
The DMM temperature conversion algorithm will contribute
0.07
°
C of error for a type K thermocouple.
■ Reference junction sensor
The primary factor determining reference junction accuracy is the operating temperature. By using the Model 2001-
TCSCAN in the 18
°
C to 28
°
C range, maximum sensor performance is achieved. The Model 2001-TCSCAN may also be used over 0
°
C to 18
°
C and 28
°
C to 50
°
C with somewhat reduced accuracy. See the specifications at the front of this manual for details.
■ Thermocouple wire errors
In most cases, the major source of error is the thermocouple wire. For the standard grade of type K thermocouple wire, the error is 2.2
°
C or 0.75%, whichever is greater. For the special grade of type K wire, the error is 1.1
°
C or 0.4% error.
■ Temperature gradient
Although the isothermal block minimizes temperature gradients, a temperature gradient develops across the connectors. This gradient contributes to the reference error and is as follows:
• Channels 2–6: 0.22
°
C
• Channels 7–10: 0.55
°
C
■ Low-temperature accuracy
Model 2001-TCSCAN temperature accuracy specifications are given down to -100
°
C. For temperatures from -100.1
°
C and -200
°
C using type J, K, T, or E thermocouples, add an additional
±
0.1
°
C of error.
When making relative temperature measurements and not absolute measurements, it is advantageous to use adjacent
3-30
3.13.2 Path isolation
The path isolation is simply the equivalent impedance between any two test paths in a measurement system. Ideally, the path isolation should be infinite, but the actual resistance and distributed capacitance of cables and connectors results in less than infinite path isolation values for these devices.
E
DUT
R
DUT
R
PATH
E
OUT
Path isolation resistance forms a signal path that is in parallel with the equivalent resistance of the DUT, as shown in
Figure 3-7. For low-to-medium device resistance values, path isolation resistance is seldom a consideration; however, it can seriously degrade measurement accuracy when testing high-impedance devices. The voltage measured across such a device, for example, can be substantially attenuated by the voltage divider action of the device source resistance and path isolation resistance, as shown in Figure 3-8. Also, leakage currents can be generated through these resistances by voltage sources in the system.
R
DUT
E
OUT
=
E
DUT
R
PATH
R
DUT
+ R
PATH
Figure 3-8
Voltage attenuation by path isolation resistance
3.13.3 Channel resistance
The on resistance of channels 5 and 10 is approximately
<240
Ω
. For this reason, you should not use channels 5 and
10 for low-to-medium 2-wire resistance measurements
(<100k
Ω
). For example, measuring a 1k
Ω
resistor using channel 5 or channel 10 will result in an error of more than
25%.
R
PATH
R
IN
V
E
DUT
DUT
Scanner
Card
Model 2001
R
DUT
= Source Resistance of DUT
E
DUT
= Source EMF of DUT
R
PATH
= Path Isolation Resistance
R
IN
= Input Resistance of Model 2001
Figure 3-7
Path isolation resistance
3.13.4 Magnetic fields
When a conductor cuts through magnetic lines of force, a very small current is generated. This phenomenon will frequently cause unwanted signals to occur in the test leads of a scanning system. If the conductor has sufficient length, even weak magnetic fields like those of the earth can create sufficient signals to affect low-level measurements. Two ways to reduce these effects are: (1) reduce the lengths of the test leads, and (2) minimize the exposed circuit area. In extreme cases, magnetic shielding may be required. Special metal with high permeability at low flux densities (such as mu metal) is effective at reducing these effects.
3-31
Even when the conductor is stationary, magnetically induced signals may still be a problem. Fields can be produced by various signals such as the AC power line voltage. Large inductors such as power transformers can generate substantial magnetic fields, so care must be taken to keep the switching and measuring circuits a good distance away from these potential noise sources. At high current levels, even a single conductor can generate significant fields. These effects can be minimized by using twisted pairs, which will cancel out most of the resulting fields.
3.13.5 Electromagnetic Interference (EMI)
The electromagnetic interference characteristics of the
Models 2000/2001/2002 Multimeters comply with the electromagnetic compatibility (EMC) requirements of the European Union (EU) directives as denoted by the
CE mark. However, it is still possible for sensitive measurements to be affected by external sources. In these instances, special precautions may be required in the test setup.
Sources of EMI include:
• Radio and television /broadcast transmitters.
• Communications transmitters, including cellular phones and handheld radios.
• Devices incorporating microprocessors and highspeed digital circuits.
• Impulse sources as in the case of arcing in highvoltage environments.
The instrument, measurement leads, and other cables should be kept as far away as possible from any EMI sources. Shielding measurement leads and the multimeter may reduce EMI to acceptable levels. In extreme cases, a specially constructed screen room may be required to sufÞciently attenuate troublesome signals.
Many instruments incorporate internal Þltering that may help reduce EMI effects. In some cases, additional external Þltering may be required. Keep in mind, however, that Þltering may have detrimental effects on the measurement.
3.13.6 Ground loops
When two or more instruments are connected together, care must be taken to avoid unwanted signals caused by ground loops. Ground loops usually occur when sensitive instrumentation is connected to other instrumentation with more than one signal return path such as power line ground.
As shown in Figure 3-9, the resulting ground loop causes current to flow through the instrument LO signal leads and then back through power line ground. This circulating current develops a small but undesirable voltage between the
LO terminals of the two instruments. This voltage will be added to the source voltage, affecting the accuracy of the measurement.
Instrument 1
Ground Loop
Current
Figure 3-9
Power line ground loops
Signal Leads
Instrument 2
Figure 3-10
Eliminating ground loops
Power Line Ground
Instrument 3
Figure 3-10 shows how to connect several instruments together to eliminate this type of ground loop problem. Here, only one instrument is connected to power line ground.
Ground loops are not normally a problem with instruments having isolated LO terminals. However, all instruments in the test setup may not be designed in this manner. When in doubt, consult the manual for all instrumentation in the test setup.
Instrument 1 Instrument 2
Power Line Ground
Instrument 3
3-32
3.13.7 Keeping connectors clean
As is the case with any high-resistance device, the integrity of connectors can be compromised if they are not handled properly. If connector insulation becomes contaminated, the insulation resistance will be substantially reduced, affecting high-impedance measurement paths. Oils and salts from the skin can contaminate connector insulators, reducing their resistance. Also, contaminants present in the air can be deposited on the insulator surface. To avoid these problems, never touch the connector insulating material. In addition, the scanner card should be used only in clean, dry environments to avoid contamination.
If the connector insulators should become contaminated, either by inadvertent touching, or from air-borne deposits, they can be cleaned with a cotton swab dipped in clean methanol.
After thoroughly cleaning, they should be allowed to dry for several hours in a low-humidity environment before use, or they can be dried more quickly using dry nitrogen.
3-33
3-34
Service Information
WARNING
The information in this section is intended only for qualified service personnel. Some of the procedures may expose you to hazardous voltages that could result in personal injury or death. Do not attempt to perform these procedures unless you are qualified to do so.
4.6
Principles of operation:
Briefly discusses circuit operation.
4.7
Troubleshooting:
Presents some troubleshooting tips for the Model 2001-TCSCAN including relay replacement precautions.
4.8
Scanner card modification:
Explains the procedure for removing the current-limiting resistors in channels
5 and 10.
4.1
Introduction
This section contains information necessary to service the
Model 2001-TCSCAN scanner card and is arranged as follows:
4.2
Handling and cleaning precautions:
Discusses handling precautions and methods to clean the card should it become contaminated.
4.3
Performance verification:
Covers the procedures necessary to determine if the scanner card meets stated specifications.
4.4
Calibration:
Describes calibrating the card reference junction to its specified accuracy.
4.5
Special handling of static-sensitive devices:
Reviews precautions necessary when handling staticsensitive devices.
4.2
Handling and cleaning precautions
Because of the high-impedance areas on the Model 2001-
TCSCAN, care should be taken when handling or servicing the card to prevent possible contamination. The following precautions should be observed when servicing the card.
4.2.1
Handling precautions
• Handle the card only by the edges and shields.
• Do not touch any board surfaces or components not associated with the repair.
• Do not touch areas adjacent to electrical contacts.
• When servicing the card, wear clean cotton gloves.
• Do not store or operate the card in an environment where dust could settle on the circuit board.
4-1
• Use dry nitrogen gas to clean dust off the board if necessary.
4.3.1
Environmental conditions
All verification measurements should be made at an ambient temperature between 18
°
and 28
°
C, and at a relative humidity of less than 70%.
4.2.2
Soldering precautions
Should it become necessary to use solder on the circuit board, observe the following precautions:
• Use an OA-based (organic activated) flux, and take care not to spread the flux to other areas of the circuit board.
• Remove the flux from the work areas when the repair has been completed. Use pure water along with clean cotton swabs or a clean, soft brush to remove the flux.
• Once the flux has been removed, swab only the repaired area with methanol, then blow dry the board with dry nitrogen gas.
• After cleaning, the card should be allowed to dry in a
50
°
C low-humidity environment for several hours before use.
4.3.2
Recommended equipment
Table 4-1 summarizes the equipment needed for performance verification and calibration (covered in paragraph 4.4). The
Model 2001 DMM is used in the procedures. However, you can also use the Model 2000, 2002, or 2010. If using the Model 2000 or 2010, you may have to alter some procedure steps slightly.
4.3.3
Scanner card connections
Jumper wires or connecting cables can simply be hard-wired directly to the screw terminals of the Model 2001-TCSCAN.
Detailed connection information is provided in Section 2.
4.3
Performance verification
The following paragraphs discuss performance verification procedures for the Model 2001-TCSCAN, including reference junction, path resistance, contact potential, and isolation.
CAUTION
Contamination will degrade the performance of the card. To avoid contamination, always grasp the card by the side edges and covers. Do not touch connector insulators, board surfaces, or components.
NOTE
Failure of any performance verification test may indicate that the scanner card is contaminated. See paragraph 4.2 for information on cleaning the card.
4.3.4
Reference junction test
This procedure verifies that the Model 2001-TCSCAN card is operating within its temperature specification. The Model
2001 Multimeter is used to close Channel 1 of the card.
A second DMM must be used to make the voltage measurements because the Model 2001 will not meet specifications with the cover removed.
1. Remove the top shield from the Model 2001-TCSCAN, and install it in the first Model 2001. Remove the Model
2001 cover to allow access to the card (see paragraph
4.7.2).
2. Turn on the second Model 2001, and set it to the
200mVDC range. Short the test lead ends together. Zero the multimeter after the thermals have stabilized (one hour if from cold-start).
3. Set up the test equipment as shown in Figure 4-1, and let it warm up one hour. Be sure to protect the card from air drafts. Use a probe with a specified accuracy of
±
0.005
°
C. The combination of the probe and reference thermometer should be accurate to
±
0.03
°
C.
4-2
4. Coat the probe with a thermally conductive compound, and insert it into the 0.110” hole marked “CAL” on the
Model 2001-TCSCAN printed circuit board.
5. Use the Model 2001 #1 front panel CHAN key to close
Channel 1.
6. Take a reading from the reference thermometer (T
J
). Use the following equation to calculate the equivalent reference junction output voltage (V
REF
):
V
REF
= (T
J
+ 273.15)
×
0.0002
7. Read the voltage across the output of OUT A (Model
2001 #2). Compare the measured and calculated voltages. If they differ by more than 72
µ
V (0.36
°
C), perform the calibration procedure of paragraph 4.4.1.
Table 4-1
Verification and calibration equipment
Description
DMM*
Electrometer w/voltage source
Sensitive Digital Voltmeter
Triax cable (unterminated)
Model or part
Keithley Model 2001
Keithley Model 6517
Specifications
20
Ω
, 72ppm
200k
Ω
, 90ppm
200mV, 37ppm
20pA, 200pA; 1.6%
200V source; 0.05%
3mV; 60ppm
Low thermal cable (unterminated)
Thermistor probe
Reference thermometer
Distilled water ice bath
(Dewar flask or Thermos)
#22 AWG solid copper wire
#22 AWG Teflon-insulated stranded wire
Keithley Model 182
Keithley Model 237-
ALG-2
Keithley Model 1484
Thermometrics Series
CSP A207A
—
—
—
—
—
—
±
±
±
0.005
0.01
0.1
—
—
°
°
C
°
C accuracy
C w/thermistor
* Two DMMs are required for thermistor calibration method and reference junction test.
Applications
Path resistance
Calibration
Reference junction, calibration
Offset current, path isolation
Contact potential
Offset current
Contact potential
Reference junction, calibration
Reference junction, calibration
Calibration
Path resistance
Path isolation
4-3
Model 2001-TCSCAN installed in
Model 2001#1 (Not shown)
Reference
Thermometer
Thermistor
Probe
Input
HI
PREV
DISPLAY
NEXT
POWER
SENSE
Ω
4 WIRE
HI
INPUT
350V
PEAK
1100V
PEAK
DCV ACV DCI ACI
Ω
2
Ω
4
REL TRIG STORE RECALL FILTER MATH
INFO LOCAL CHAN SCAN CONFIG MENU
2001 MULTIMETER
FREQ TEMP
RANGE
AUTO
RANGE
EXIT ENTER
F
INPUTS
LO
R
FRONT/REAR
2A 250V
AMPS
500V
PEAK
CAL
Input
LO
Copper Wires
Model 2001 #2
(Measure DCV)
Figure 4-1
Connections for reference junction test
OUT A HI
OUT A LO
4.3.5
Path resistance tests
Perform the following steps to verify that the path resistance of each channel is with specified values.
1. Connect the HI and LO terminals of all nine channel inputs together using #22AWG solid copper jumper wires
(see Figure 4-2).
NOTE
Make sure that all jumper wires are clean and free of oxides.
2. Connect the output cables to OUT A HI and LO, as shown in Figure 4-2.
3. With the power off, install the scanner card in the Model
2001 Multimeter.
4-4
4. Turn on the Model 2001, and allow it to warm up for one hour before proceeding.
5. Select the
Ω
2W function and the 20
Ω
range on the Model 2001.
6. Temporarily connect a second set of output leads, identical in length and type to the leads connected to the scanner card output, to the Model 2001 rear panel HI and LO INPUT jacks. Be sure to select the rear panel terminals with the front panel INPUTS switch.
7. Short the free ends of the temporary leads together, and allow the reading to settle. Enable the Model 2001 REL mode after settling, and leave REL enabled for the remainder of the path resistance tests.
8. Disconnect the temporary leads from the multimeter, and connect the output leads from the scanner card to the rear panel HI and LO INPUT jacks (see Figure 4-2).
9. Close channel 2 as follows;
A. From normal display, press CHAN. The instrument will display the following:
CHANNEL SELECTION
CLOSE-CHANNEL OPEN-ALL-CHANNELS
B. Select CLOSE-CHANNEL, then press ENTER.
The Model 2001 will display the following:
ENTER CHAN#01 (1-10)
C. Using the range and cursor keys, select channel 02, then press ENTER.
D. Press EXIT to return to normal display.
10. Note the resistance reading on the Model 2001. Verify that the reading is <2
Ω
.
11. Repeat steps 9 and 10 for channels 3-10. Verify that the path resistance for each channel is as follows:
• Channels 2-4, 6-9: <2
Ω
.
• Channels 5 and 10: <252
Ω
.
NOTE
Change to the 2k
Ω
resistance range when measuring channels 5 and 10. Always use the lowest possible range for best accuracy.
12. After completing the tests, turn off the Model 2001 power, remove the scanner card, and remove all jumper wires (leave HI and LO shorted for each channel if you intend to perform contact potential tests).
4.3.6
Contact potential tests
These tests check the EMF (contact potential) generated by each relay contact pair (HI and LO) for each channel. The tests use a sensitive digital voltmeter (Model 182) to measure the contact potential.
Perform the following procedure to check contact potential of each channel.
1. Connect 1” #22AWG copper jumper wires between the
HI and LO terminals of each channel input (see Figure
4-3).
2. Connect the Model 182 to OUT A HI and LO using the low-thermal cable (see Figure 4-3).
3. With the power off, install the scanner card in the Model
2001 Multimeter.
4. Turn on the Model 2001 and the Model 182 Sensitive
Digital Voltmeter. Allow the Model 182 to warm up for two hours before measurement.
5. Select the 3mV range on the Model 182.
6. Select the DCV function on the Model 2001.
7. Using the CHAN key, close channel 2 (see paragraph
4.3.5 for procedure).
8. Verify that the Model 182 reading is <1
µ
V.
9. Repeat steps 7 and 8 for all nine channels. The reading for channels 2-4 and 6-9 should be <1 ing for channels 5 and 10 should be <2
µ
µ
V, and the read-
V.
10. After completing all measurements, turn off the Model
2001 power, remove the scanner card, and disconnect all jumpers and test leads.
4-5
Jumper HI and LO of All Nine Channels
Channel 1
REF
JCN
Channel 2
HI
LO
Channel 3-4
Channel 5
HI
LO
4-Pole
Channel 6
HI
LO
Channel 7-9
Channel 10
HI
LO
Model 2001-TCSCAN
2-Pole
HI
LO
OUT A
HI
LO
OUT B
Input
HI
Input
LO
Model 2001
Rear Panel
Figure 4-2
Connections for path resistance checks
4-6
Model 1484
Low Thermal Cable
(Unterminated)
KEITHLEY 182 SENSITIVE DIGITAL VOLTMETER
TRG
SRQ
REM
TALK
LSTN
Connect bare copper jumpers between HI and LO
Model 182
Channel 1
REF
JCN
Channel 2
HI
LO
Channel 3-4
Channel 5
HI
LO
4-Pole
Channel 6
HI
LO
Channel 7-9
Channel 10
HI
LO
Model 2001-TCSCAN
2-Pole
HI
LO
OUT A
HI
LO
OUT B
Figure 4-3
Connections for contact potential tests
4-7
4.3.7
Isolation tests
These tests check the leakage resistance (isolation) between all HI and LO terminals and from HI and LO terminals to chassis ground. In general, the test is performed by applying a voltage (100V) across the terminals and then measuring the leakage current. The isolation resistance is then calculated as
R = V/I. In the following procedure, the Model 6517 functions as a voltage source and as an ammeter. In the resistance (R) function, the Model 6517 internally calculates the resistance from the known voltage and current levels, and displays the resistance value.
Perform the following steps to check isolation:
1. Connect a 4” length of Teflon-insulated #22AWG stranded wire to every HI and LO terminal on the scanner card (both inputs and outputs). Mark the free end of each wire so you can identify wires when the scanner card is installed.
2. With the power off, install the scanner card in the multimeter.
3. Turn on the Model 2001 power.
4. Turn on the Model 6517, and allow the unit to warm up for one hour for rated accuracy.
5. With the V-Source in standby (OPERATE indicator off) and zero check enabled (Zero Check displayed), configure the Model 6517 to make >1G
Ω
resistance (R) measurements using a V-Source value of +100V. Refer to the
Model 6517 User’s manual for details on electrometer operation.
WARNING
The following steps use high voltage
(100V). Be sure the V-Source is in standby before making connection changes.
6. With the Model 6517 in standby, connect the electrometer to OUT A HI and LO terminals of the scanner card, as shown in Figure 4-4.
7. Close channel 2 using the CHAN key (see paragraph
4.3.5 for details).
8. On the Model 6517, disable zero check, and press OPER to source 100V.
9. After allowing the reading on the Model 6517 to settle, verify that the reading is >1G
Ω
(10
9
Ω
). This measurement represents the isolation resistance between the HI and LO terminals of channel 2.
10. Place the Model 6517 in standby, and enable zero check.
11. Repeat steps 7 through 10 for channels 3 through 10. Be sure that the channel under test is closed.
12. With the Model 6517 voltage source in standby, connect the electrometer to the HI terminals of scanner card channels 2 and 3, as shown in Figure 4-5.
13. Close channel 2 using the CHAN key.
14. On the Model 6517, disable zero check, and press
OPER to source 100V.
15. After allowing the reading on the Model 6517 to settle, verify that the reading is >1G
Ω
(10
9
Ω
). This measurement represents the isolation resistance between the HI terminals of channels 2 and 3.
16. Place the Model 6517 in standby, and enable zero check.
17. Repeat steps 12 through 16 to measure isolation resistance between the channel 2 HI terminal and channels 4 through 10 HI terminals. Be sure that the electrometer is connected to the HI terminals of the two channels being tested, and that channel 2 is closed.
18. Repeat steps 12 through 17 for the LO terminals of channels 2 through 10. Be sure the electrometer is connected to the LO terminals of the two channels being tested, and that channel 2 is closed.
19. With the electrometer voltage source in standby, connect the electrometer to channel 2 HI and chassis ground, as shown in Figure 4-6.
20. Program the Model 2001 to close channel 2.
21. On the Model 6517, disable zero check, and press
OPER to source +100V.
22. After allowing the reading on the Model 6517 to settle, verify that it is >1G
Ω
(10
9
Ω
).
23. Put the electrometer in standby, and enable zero check.
24. Repeat steps 19 through 23 for channels 3 through 10.
One electrometer lead should be connected to the HI terminal of the channel being testing, and the other lead should be connected to chassis ground.
25. Repeat steps 19 through 24 for channels 2 through 10
LO terminals. One electrometer lead should be connected to the LO terminal of the channel being tested, and the other lead should be connected to chassis ground. In addition, channel 2 should be closed.
4-8
Model 237-ALG Triax Cable
HI
(Red)
Banana Cable
Ground
Link
Removed
Input Common
LO
V-Source
HI
Model 6517
Banana Cable (one end unterminated)
Channel 1
REF
JCN
Channel 2
HI
LO
Channel 3-4
Channel 5
HI
LO
4-Pole
Channel 6
HI
LO
Channel 7-9
Channel 10
HI
LO
Model 2001-TCSCAN
2-Pole
HI
LO
OUT A
HI
LO
OUT B
Figure 4-4
Connections for same-channel isolation tests
Model 237-ALG Triax Cable
HI
(Red)
Banana Cable
Ground
Link
Removed
Input Common
LO
V-Source
HI
Model 6517
Banana Cable (one end unterminated)
Channel 1
REF
JCN
Channel 2
HI
LO
Channel 3-4
Channel 5
HI
LO
4-Pole
Channel 6
HI
LO
Channel 7-9
Channel 10
HI
LO
Model 2001-TCSCAN
2-Pole
HI
LO
OUT A
HI
LO
OUT B
Figure 4-5
Connections for channel-to-channel isolation tests
4-9
Model 237-ALG Triax Cable
HI
(Red)
Banana Cable
Ground
Link
Removed
Input Common
LO
V-Source
HI
Model 6517
Banana Cable (one end unterminated)
Model 2001
Chassis Ground
Channel 1
REF
JCN
Channel 2
HI
LO
Channel 3-4
Channel 5
HI
LO
4-Pole
Channel 6
Channel 7-9
HI
LO
Channel 10
HI
LO
Model 2001-TCSCAN
HI
LO
OUT A
2-Pole
HI
LO
OUT B
Figure 4-6
Connections for HI and LO terminal to chassis ground isolation tests
4.4
Calibration
There are two calibration procedures given here. The first procedure establishes the specified accuracy of the Model
2001-TCSCAN card with a calibrated thermistor probe monitoring the temperature of the isothermal block. The second procedure establishes an ice-point reference for a piece of thermocouple wire from the spool intended for a Model
2001-TCSCAN application.
2001 Multimeter being used for normal applications.
4.4.1
Calibration with thermistor probe
This procedure requires a calibrated thermistor probe (Thermometrics Series CSP A207A or equivalent). The test can be automated with a bus controller.
Both calibration procedures should be performed at an ambient temperature of 23
°
C
±
3
°
C, and a relative humidity of less than 70%.
NOTE
It is recommended that the Model 2001-
TCSCAN be calibrated in the same Model
Bench reset conditions are assumed for the Model 2001. In general, the procedure has the followings steps:
1. Set the Model 2001 Multimeter to the 200k
Ω
range.
(The short circuit current is 7
µ
A. Due to the self-heating effects of the thermistor probe at higher current, do not
4-10
use a lower resistance range.) Let the Model 2001 warm up for one hour.
2. Set another Model 2001 to the 200mV DC range. Insert a 2-terminal low thermal shorting bar into the voltage inputs. Zero the Model 2001 after one hour, and remove the shorting bar.
3. Set up the test equipment as shown in Figure 4-7. Remove the cover of the Model 2001 as explained in paragraph 4.7.2.
4. Remove the card top shield and cable clamp. Insert the card into the Model 2001, and protect it from air drafts.
5. Coat the probe with a thermally conductive compound, and insert it into the 0.110-inch hole marked “CAL” on the PC board.
6. Take a reading of the probe resistance when it stabilizes.
7. Using the lookup tables for the CSP A207A probe, find the Celsius temperature that corresponds to the above probe resistance. This value is the temperature of the isothermal block as measured by the probe.
8. The following equation calculates the equivalent reference junction output voltage (V
REF
):
V
REF
= (T
J
+ 273.15)
×
0.0002
9. Close Channel 1 on the Model 2001-TCSCAN card, and read the output voltage; it should equal the V
REF
voltage just calculated. Adjust trimmer R151 until the equivalent temperature equals: probe temp.
±
0.05
°
C
10. Check the probe resistance again, and find the corresponding temperature with the lookup tables. If the new value differs by more than 0.01
°
C from the temperature found in step 7, repeat steps 8 and 9.
4.4.2
Calibration with thermocouple wire
This procedure compensates for errors of the reference junction circuitry and establishes a compensation factor for the offset of the particular piece of thermocouple wire. Because of an inherent error source, (the thermocouple wire used in measuring the ice-point), absolute calibration accuracy cannot be guaranteed.
Assuming the homogeneity of the thermocouple wire spool, errors due to thermocouple offset voltages will be significantly reduced for the entire system. For subsequent applications of this particular Model 2001-TCSCAN card, the same spool of wire should be used on the same channel; otherwise the Model 2001-TCSCAN should be recalibrated. This example uses channel 2. Change connections and setup appropriately for other channels.
This procedure assumes bench reset conditions on the Model
2001.
1. On the Model 2001-TCSCAN, connect the thermocouple positive lead to Channel 2 HI and the negative lead
(red insulation) to Channel 2 LO. Connect copper wires to the HI and LO terminals of OUT A. Remove the cable clamp, and insert a non-metallic screwdriver to adjust trimmer R151. See Figure 4-8.
2. Insert the Model 2001-TCSCAN into a Model 2001.
Connect the output wires to the INPUT HI and LO terminals of the Model 2001.
3. Turn on the instrument, and allow it to warm up for at least one hour.
4. Fill a Dewer flask or Thermos half full with pea-sized ice made from distilled water. Fill up the flask with distilled water. Stir the contents.
5. Place a twisted or welded thermocouple junction into the volume of the flask occupied by ice. Cover the flask, and stir contents occasionally. Allow 20 minutes for temperature stabilization. Add more ice as necessary.
6. On the Model 2001, select the TEMP function and configure it as follows:
• Select a thermocouple temperature sensor, and choose the appropriate type.
• Configure reference junction #1 (JCN1) with the temperature coefficient (+00.20mV/
°
C) and offset voltage (+54.63mV @ 0
°
C) for the Model 2001-
TCSCAN.
• Select temperature units of DEG-F (to yield better resolution than DEG-C).
7. From the CONFIG-CHAN menu of the Model 2001, select internal inputs, the JN1 function for Channel 1, and the TMP function for Channel 2. (Set all other channels to ---.)
4-11
PREV
DISPLAY
NEXT
POWER
Ω
SENSE
4 WIRE
HI
INPUT
DCV ACV DCI ACI
Ω
2
Ω
4
REL TRIG
INFO LOCAL
STORE RECALL FILTER MATH
CHAN SCAN CONFIG MENU
350V
PEAK
1100V
PEAK
2001 MULTIMETER
FREQ TEMP
RANGE
AUTO
RANGE
F
INPUTS
LO
R
FRONT/REAR
2A 250V
AMPS
500V
PEAK
CAL
EXIT ENTER
Sense
Ω
HI
Input HI
Input LO
Sense
Ω
LO
Model 2001 #1
(Measure 4-wire ohms)
Thermistor
Probe
Input HI
Input LO
R151 CAL adjustment
Model 2001 #2
(Measure DCV)
Copper Wires
OUT A HI
OUT A LO
Note : Install card in Model 2001 #2
Figure 4-7
Calibration with thermistor probe
8. Start scanning as follows:
A. Press SCAN, enter a SCAN COUNT of 99999, then press ENTER.
B. Select SCAN TIMER operation, then press EN-
TER.
C. Choose a scan INTRVL of 1.5, then press ENTER.
D. Choose NO DATA TO MEMORY, then press
ENTER.
E. Press ENTER to begin scanning.
9. Note the reading on the Model 2001 display when Channel 2 is closed. If the display reads other than 32.0
°
F, adjust trimmer R151 on the Model 2001-TCSCAN card until the Model 2001 reads 32.0
°
F,
±
1 count.
10. Press EXIT on the Model 2001 to stop the scan.
4-12
Channel 2 HI
Channel 2 LO
OUT A LO
OUT A HI
Model 2001-TCSCAN in Model 2001
R151 Cal
Adjustment
Ice Bath
Copper Wires
Input
HI
Input
LO
Model 2001
(Measure Temperature)
Figure 4-8
Calibration with thermocouple wire
4.5
Special handling of static-sensitive devices
CMOS and other high-impedance devices are subject to possible static discharge damage because of the high-impedance levels involved. When handling such devices, use the precautions listed below.
3. Handle the devices only by the body; do not touch the pins or terminals.
4. Any printed circuit board into which the device is to be inserted must first be grounded to the bench or table.
5. Use only anti-static type de-soldering tools and grounded-tip soldering irons.
NOTE
In order to prevent damage, assume that all parts are static-sensitive.
4.6
Principles of operation
The following paragraphs discuss the basic operating principles for the Model 2001-TCSCAN, and can be used as an aid in troubleshooting the card. The schematic drawing of the card is located at the end of Section 5.
1. Such devices should be transported and handled only in containers specially designed to prevent or dissipate static build-up. Typically, these devices will be received in anti-static containers made of plastic or foam. Keep these parts in their original containers until ready for installation or use.
2. Remove the devices from their protective containers only at a properly grounded workstation. Also, ground yourself with an appropriate wrist strap while working with these devices.
4.6.1
Block diagram
Figure 4-9 shows a simplified block diagram of the Model
2001-TCSCAN. Key elements include the relay drivers and relays, and the power-up reset circuit. These various elements are discussed in the following paragraphs.
4-13
To 2001
Multimeter
Clock
Data
Strobe
Relay
Drivers
U101-U103
Relays,
Enable
Power-on
Reset
U104
K101-K113
User Connections
+5V
4.6.5
Reference junction
The reference junction for cold junction compensation is made up of U105 and associated components. Calibration adjustment is provided by R151.
Figure 4-9
Block diagram
4.7
Troubleshooting
4.7.1
Troubleshooting equipment
Table 4-2 summarizes recommended equipment for troubleshooting the Model 2001-TCSCAN.
4.6.2
Relay control
Card relays are controlled by serial data transmitted via the relay DATA line. A total of three bytes are shifted in serial fashion into latches located in the card relay driver ICs. The serial data is clocked in by the CLOCK line. As data overflows one register, it is fed out the Q’S line of the register down the chain.
Table 4-2
Recommended troubleshooting equipment
Description
Multimeter
Oscilloscope
Manufacturer and model
Keithley 2001
TEK 2243
Application
DCV checks
View logic waveforms
Once all three bytes have shifted into the card, the STROBE line is set high to latch the relay information into the Q outputs of the relay drivers, and the appropriate relays are energized (assuming the driver outputs are enabled, as discussed below). Note that a relay driver output goes low to energize the corresponding relay.
4.6.3
Switching circuits
Relays K101 through K106 and K108 to K113 perform input switching, while K107 configures the card for 2-pole or 4pole operation.
4.6.4
Power-on safeguard
A power-on safeguard circuit, made up of U104 and associated components, ensures that relays do not change state on power-up and power-down. This circuit disables all relay actuation during power-up and power-down periods by holding the OE (output enable lines) high during these periods.
4.7.2
Troubleshooting access
In order to gain access to the scanner card circuit board to measure voltages under actual operating conditions, perform the following steps:
1. Turn off the Model 2001 power, and disconnect the line cord and all other equipment.
2. If wires are connected to the scanner card, remove the scanner card from the multimeter.
3. Remove the Model 2001 cover as follows:
A. Remove the handle by rotating it to align the arrows on the handle mounting ears. Pull out and remove the handle.
B. Remove the screws that secure the handle mounting ears, then remove the ears.
C. Remove the screws that attach the rear bezel to the case, then remove the bezel.
D. Remove the bottom screw that grounds the case to the chassis.
4-14
WARNING
Be sure to install and tighten the grounding screw after replacing the cover.
E. Remove the cover by pulling it off towards the rear.
4. Disconnect any wires connected to the scanner card terminal blocks.
5. Install the scanner card in the multimeter.
6. Connect the line cord, and turn on the power to measure voltages (see following paragraph).
4.7.3
Troubleshooting procedure
Table 4-3 summarizes scanner card troubleshooting steps.
Refer to the schematic diagram and component layout drawings at the end of Section 5 for component locations.
WARNING
Lethal voltages are present within the
Model 2001. Some of the procedures may expose you to hazardous voltages.
Observe standard safety precautions for dealing with live circuits. Failure to do so could result in personal injury or death.
CAUTION
Observe the following precautions when troubleshooting or repairing the scanner card:
1. To avoid contamination, which could degrade card performance, always handle the card only by the side edges and covers. Do not touch edge connectors, board surfaces, or components on the card. Also, do not touch areas adjacent to electrical contacts on connectors.
2. Use care when removing relays from the PC board to avoid pulling traces away from the circuit board. Before attempting to remove a relay, use an
4.8
appropriate de-soldering tool, such as a solder sucker, to clear each mounting hole completely free of solder. Each relay pin must be free to move in its mounting hole before removal. Also, make certain that no burrs are present on the ends of the relay pins.
3. If the bottom shield must be replaced, make sure that the overlay, which contains warning messages, is also replaced.
4. Removing the isothermal block will damage the conductive RTV adhesive. The RTV adhesive must be replaced if the isothermal block is removed.
Scanner card modification
Channels 5 and 10 include 120
Ω
resistors in series with the
HI and LO terminals in order to avoid possible card damage should the high-speed multiplexing, ratio, or delta modes be inadvertently selected. (Damage may occur because breakbefore-make operation for channels 5 and 10 cannot be guaranteed when the high-speed scanning modes of the Model
2001 Multimeter are selected). These resistors can be removed and replaced with jumper wires in cases where the nominal 240
Ω
path resistance may affect signals switched through channels 5 and 10.
CAUTION
Use extreme care after replacing current-limiting resistors with jumper wires. External sources connected to channels 5 and 10 should be currentlimiting to a maximum current of 1A, and the ratio, delta, and high-speed multiplexing modes of the Model 2001
Multimeter should not be used with the
Model 2001-TCSCAN.
Figure 4-10 shows the location of the factory-installed current-limiting resistors. R152 and R153 provide current limiting for channel 5, while R154 and R155 perform the same function for channel 10. To make the modification, simply
4-15
unsolder the current-limiting resistors, then solder jumpers wires in their places. Jumper part number J-3 may be ordered directly from Keithley Instruments, Inc.
NOTE
Observe the soldering and cleaning precautions discussed in paragraph 4.2.2
when making board modifications. Circuit board contamination may degrade card performance.
4
5
2
3
6
Table 4-3
Troubleshooting procedure
Step Item/component
1 Digital ground P1034, pin 1, 3, 5
7
P1034, pin 9
U101, pin 2
U101, pin 3
U101, pin 7
U101-U103, pins 10-18
U105, pin 2
Required condition
+5VDC
CLOCK pulses
DATA pulses
STROBE pulse
Low when relay state is changed. High when relay is not changing state.
+54.63mV @ 0
°
C, or +59.23mV
@ +23
°
C
Comments
All voltages referenced to digital ground.
Card power supply voltage.
Serial clock pulses.
Serial data pulses.
End of relay update sequence.
Relay driver outputs.
Reference junction output (see paragraph 4.3.4).
HI LO
CH 2
HI LO
CH 3
HI LO
CH 4
HI LO
CH 5
HI LO
CH 6
HI LO
CH 7
HI LO
CH 8
HI LO
CH 9
HI LO
CH 10
HI LO HI LO
OUT A OUT B
Figure 4-10
Current-limiting resistor locations
Channel 5
Current-limiting
Resistors
4-16
Channel 10
Current-limiting
Resistors
Replaceable Parts
5.1
Introduction
This section contains replacement parts information, schematic diagram, and component layout drawing for the Model
2001-TCSCAN.
5.2
Parts list
A parts list for the scanner card is included in a table integrated with schematic diagram and component layout drawing for the board. Parts are listed alphabetically in order of circuit designation.
5.4
Factory service
If the card is to be returned to Keithley Instruments for repair, perform the following:
• Call the Instruments Division Repair Department at 1-
800-552-1115 for a Return Material Authorization
(RMA) number.
• Complete the service form at the back of this manual, and include it with the card.
• Carefully pack the card in the original packing carton.
• Write ATTENTION REPAIR DEPT and the RMA number on the shipping label.
5.3
Ordering information
To place an order, or to obtain information concerning replacement parts, contact your Keithley representative or the factory (see inside front cover for addresses). When ordering parts, be sure to include the following information:
• Card model number (2001-TCSCAN)
• Card serial number
• Part description
• Circuit description, if applicable
• Keithley part number
NOTE: It is not necessary to return the Model 2001 Multimeter with the card.
5.5
Component layout and schematic diagram
A component layout drawing and schematic diagram are included on the following pages integrated with the parts list for the Model 2001-TCSCAN.
5-1
Table 5-1
Electrical parts
Circuit desig.
C101-103,105,106,108,109
C104
C107
E104
J1035
J1036
K101-111
K112,113
P1034
R134
R147
R148
R149
R150
R151
R152-155
U101-103
U104
U105
Description
CAP,.1UF,20%,50V,CERAMIC
CAP, 10UF, 20%, 50V, ALUM ELEC
CAP,100UF,20%,25V,ALUM ELEC
SURGE ARRESTOR CG2-300L
CONN, FEMALE 16-PIN
CONN, FEMALE 12-PIN
RELAY, MINATURE (DPDT) TQ2E-L2-5V
RELAY, ULTRA-SMALL POLARIZED TF2E-5V
CONN, FEMALE, DUAL 16-PIN
RES,1K,5%,1/4W,COMPOSITION OR FILM
RES,4.7K,5%,1/4W,COMPOSITION OR FILM
RES,5.62K,1%,1/8W,METAL FILM
RES, 205, .1%, 1/10W, METAL FILM
RES,100,5%,1/4W,COMPOSITION OR FILM
POT,10K,10%,.75W,NON-WIREWOUND
RES, 120, 5%, 1/4W, COMPOSITION OR FILM
IC, 8-BIT SERIAL-IN LATCH DRIVER,5841A
IC,SUPPLY VOLTAGE SUPERVISOR,TL7705AC
IC, TEMPERATURE TRANSDUCER, AD590MH
Part number
C-365-.1
C-489-10
C-413-100
SA-2
TE-118-10
TE-118-12
RL-155
RL-149
CS-455
R-76-1K
R-76-4.7K
R-88-5.62K
R-263-205
R-76-100
RP-89-10K
R-76-120
IC-536
IC-602
IC-892
5-2
Table 5-2
Mechanical parts
Description
CLIP, STRAIN RELIEF
COPPER ISOTHERMAL BLOCK
STRIP, POLYURETHANE
STRAIN RELIEF, TOP
SHIELD, TOP
STRAIN RELIEF, BOTTOM
BOTTOM SHIELD
CARD EJECTOR, PLASTIC
SLEEVED BANANA PLUG TEST LEAD
CHIPLOC BAG STATIC SHIELDING
OVERLAY, BOTTOM SHIELD
THERMAL RTV
Part Number
2001-351A
2001-TCSCAN-302A
2001-345-1B
2001-349A
1801-307A
2001-344B
2001-TCSCAN-304A
FA-237
CA-109A
PO-13-1
2001-TCSCAN-305A
CE-16
5-3
Thermocouple Basics
A.1
Definitions
The following terms are defined as they relate to thermocouple circuits and thermocouple switching cards:
Cold junction —
The junction that is held at a stable known temperature. Also known as the reference junction.
Hot junction —
The junction of two dissimilar metals that is used to measure an unknown temperature. Also known as the measurement junction.
Isothermal block or cover —
The metal block or cover that equalizes the temperature of thermocouple connections on a switching card.
Reference accuracy —
The maximum error between sensor and channel inside the isothermal environment. Also known as temperature offset.
Reference channel —
The channel that measures the temperature of the isothermal environment.
Reference output —
The output signal that represents the temperature of the reference channel. Commonly specified by a temperature coefficient of µV/°C and an offset voltage in millivolts at 0°C.
A.2
Theory
A thermocouple is a junction formed between two dissimilar metals. If the temperature of the thermocouple junction connected to the Model 2001-TCSCAN is T, a voltage E is developed between leads A and B as shown in Figure A-1.
When connected to a voltmeter, two more junctions (C and
D) are formed with the meter terminals. The measured voltage is proportional to the difference between temperatures T and T
1
.
T
A
B
E
Figure A-1
Thermocouple measurement
Isothermal
Terminal
Er
T1
Terminal
Copper
Et
Copper
Et = E - Er
C
V
D
To determine the difference, the thermoelectric properties of the thermocouple are needed. Data is available to determine the voltage versus temperature relationship based on a reference temperature (T
1
) of 0°C. Thus, if the thermocouple-tocopper junctions were maintained at 0°C, it would be possible to determine T by referring to the Thermocouple Reference Tables. (See NIST Nomograph 125.) The tables list temperature as a function of the meter reading E t
. Since these junctions are not 0°C, a voltage E r
is introduced, where:
E t
= E - E r
A-1
A.3
Measurement procedure
The temperature of a thermocouple junction is determined by the following summarized procedure:
• Measure the reference voltage (E
1
).
• Calculate the reference temperature (T
1
).
• Determine the reference correction voltage (E r
).
• Measure the thermocouple voltage (E t
).
• Calculate the thermocouple correction voltage (E).
• Determine the thermocouple temperature (T).
The complete step-by-step procedure follows:
1. Read the voltage (E
1
) developed by the Model 2001-TC-
SCAN reference junction. Assuming a temperature coefficient of +200µV/°C, and an offset voltage of
+54.63mV at 0°C, convert the voltage reading to temperature (T
1
) with the formula:
T
1
= (E
1
= 54.63mV) / 0.2mV per °C
T
1
represents the temperature of the Model 2001-TCS-
CAN isothermal connections.
2. Using the thermocouple lookup tables or the following formula, convert the temperature (T
1
) from step 1 to a voltage. Use tables matching the type of thermocouple connected to the Model 2001-TCSCAN. E r
corresponds to the reference voltage that would result if an actual thermocouple were used as a reference junction.
E r
= a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
3. Make a measurement of the voltage (E t
) developed by the thermocouple connected to the Model 2001-TCS-
CAN.
4. Add the reference voltage derived in step 2 to the thermocouple voltage measured in step 3.
E = E r
+ E t
5. Convert the voltage sum (E) from step 4 to a temperature
(T) using either thermocouple lookup tables or the formula:
T = a
0
+ a
1
E + a
2
E 2 + a
3
E 3 + a
4
E 4
The values for a
0
through a
4
for the supported thermocouples are listed in tables located in Appendix B.
A.4
Measuring example
A measurement setup uses a Type J thermocouple. The voltage developed by the reference junction (channel 1) is
61.83mV. The voltage read from the thermocouple is
14476µV.
1. Find the temperature of the isothermal connections. The voltage from the reference sensor is 61.83mV.
(61.83mV – 54.63mV) / 0.2mV per °C = 36°C
2. Using the appropriate formula or thermocouple lookup tables (see Table 6.3.2 of NIST Monograph 125), find the equivalent voltage developed by a Type J thermocouple at 36°C. This voltage is found to be 1849.1µV.
The formula shown in step 2 above would yield
1849.085µV.
3. The voltage developed by the thermocouple is measured as 14476µV.
4. The sum of the voltage is 14476 + 1849.1, or
16325.1µV.
5. Using the appropriate formula or thermocouple lookup tables (see Table A6.2.1 of NIST Monograph 125), find the temperature for a Type J thermocouple corresponding to 16325.1µV. This temperature is 300.0°C. The formula shown in step 5 above would yield 299.995°C.
NOTE
It is not necessary to make these calculations when using the Model 2001 Multimeter, which performs temperature conversion automatically.
A-2
Thermocouple Conversion Tables
The following thermocouple conversion tables are included as a convenience for those who wish to use the Model 2001-
TCSCAN to make thermocouple temperature measurements with other instruments. Note that the Model 2001 Multimeter does not use these tables for temperature conversion but relies instead on piecewise linear analysis to provide more accurate temperature measurements.
B-1
Thermocouple Conversion Tables
Table B-1
NIST Quartic Coefficients for Types S, R, B, E, J, K, and T
Type S
Thermocouples
1
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-50 to 900
0 to 1100
0 to 1400
0 to 1650
0 to 1768
400 to 1100
400 to 1400
400 to 1650
1050 to 1400
1050 to 1650
1400 to 1550
1400 to 1650
1666 to 1768
Reference
Junction
Correction
0 to 50
-3.8051591
-5.2412524
-5.0061921
1.4352322
1.3054176
1.8695088
1.0863331
1400 to 1768 -7.4180405
8.2703440
5.5439639
5.8791282
6.2516859
6.5554932
+2
+2
+2
+3
+3
+2
+3
+4
6.6834421
8.7228147
9.5827994
9.4591354
2.9873073
3.4129348
6.4091373
3.9952876
2.0043202
+4 -1.3532278
5.3994446
+0
+0
+0
+0
+0
+0
+0 -1.2077351
+0 -9.7986687
+0
+0
+0
+0
+2 -1.8607781
+2 8.0243878
+0
1.0103667
7.9098118
5.8347856
4.4519908
3.9334084
6.2984807
6.9951678
6.4741403
3.4664812
5.8939317
1.2467754
-2 -1.0944499
-3 -6.7450002
-3 -3.4351369
-3 -1.6378513
-3 -1.0384046
-4
-3
-4
9.0526670
2.5723104
2.3967559
-3 -1.8986036
-3 -1.6163524
-3 -2.7553724
-3 -1.3595782
-1 8.1899566
-2 -1.0633404
-2 1.9934168
-5
-6
-6
-6
-6
-7
-6
-6
-6
-6
-7
-6
-5
-5
-5
4.9628963
2.5247577
9.4022202
2.4140360
3.4244511
-2.9241601
-8.3681057
-7.8837971
6.5006637
7.9103746
-2.1606150
-3.4675031
-1.3556030
-1.7212343
-9
-9
-10
-10
-11
-10
-10
-10
-11
-12
-10
-11
-8
-9
1
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
-0.01 to +0.01
Error
Range (µV)
Exact-
Approx.
-7 to 14
-16 to 12
-35 to 25
-55 to 35
-60 to 35
-.7 to .5
-1.6 to 1.5
-1.8 to 1.9
-.05 to .05
-.05 to .05
-.05 to .05
-.05 to .05
-1.0 to 1.3
-.05 to .05
Type S
Thermocouples
2
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Error
Range (¡C)
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-50 to 900
0 to 1100
0 to 1400
0 to 1650
0 to 1768
400 to 1100
400 to 1400
400 to 1650
1050 to 1400 -3.0938374
1050 to 1650
1400 to 1550
1400 to 1650
1400 to 1768
1666 to 1768
4.1137317
4.4507790
4.1670535
1.2226507
1.3866867
1.3923740
4.5133695
2.3131446
1.6414048
1.5445376
1.4713897
1.4260554
+1
+1
+1
+1
+1
+2
+2
1.4087955
1.1599785
1.1373998
1.1543356
1.4106560
1.2706383
9.3486676
9.3267401
+3 -1.0046437
+4 -5.4122671
-1 -2.0241757
-1 -1.3349067
-1 -9.0783455
-1 -7.0073775
-1 -6.3195007
-1 -1.8642979
-1 -1.3349811
-1 -1.6782780
-1 -4.9794442
-1 -3.2873314
-2
-2
+0
+0
4.8592708
7.7266682
1.0322002
4.9347196
-5
-5
-6
-6
-6
-6
2.7849728
1.3626587
-9 -1.4172102
-13
-9 -5.3270847
-14
6.5660913
-10 -1.8499175
-14
3.8981279
-10 -8.3047780
-15
3.1267454
-10 -5.7422562
1.2643267
-11
-6 -3.9224680
-11
-6 -1.0845801
-11
8.4828836
2.6563405
1.8379726
15
-16
15
-15
Exact-
Approx.
-11 to 3
-3 to 6
-5 to 9
-6 to 11
-6 to 12
-.05 to .07
-.08 to .08
-.2 to .2
-6
-6
1.7334256
-10 -1.9262160
15
8.3038098
-11 -1.3019379
-16
-8 -6.3885209
-11
-8 -6.5458208
-11
2.2896541
2.3208160
-15
-15
-.003 to .003
-.010 to .010
-.0005 to .0005
-.0005 to .0005
-4 -4.3637046
-4 -1.9681943
-9
-8
6.9361610
-14 -.13 to .10
2.9430179
-13 -.0005 to .0005
2
Quartic approximations to the data as a function of voltage in selected temperature ranges (¡C).
The expansion is of the form T = a
0
+ a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
B-2
Thermocouple Conversion Tables
Type R
Thermocouples
3
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-50 to 900
0 to 1100
0 to 1400
0 to 1650
0 to 1768
400 to 1100
400 to 1400
400 to 1650
1050 to 1400
1050 to 1650
1400 to 1550
1400 to 1650
-4.0674108
-5.6047484
-5.4505828
1.6618159
1.5132838
2.4008703
1.5787334
1400 to 1768 -7.1904948
1666 to 1768
Reference
Junction
Correction
0 to 50
8.8532076
5.4295008
5.7622558
6.1429772
6.4615269
+2
+2
+2
+3
+3
+3
+3
+4
6.5962120
8.7490294
9.6731111
9.5942872
2.3048526
2.7958847
4.1604579
2.6321144
1.9442383
+4 -1.5014129
5.2891411
+0
+0
+0
+0
+0
+0
+0
+0
-1
+0
+0
1.1446885
9.2715271
7.1515857
5.7010917
5.1559203
1.7115155
+0 -2.6994046
+0 -1.2813352
8.7635426
8.1571403
1.0549178
8.3100314
+2 -1.7913090
+2 9.5376167
1.3844426
-2 -1.1295306
-3 -7.1346883
-3 -3.7539447
-3 -1.8683292
-3 -1.2385309
-3
-4
-4
7.5039035
2.5536988
2.4468512
-3 -2.3016819
-3 -1.9701159
-2 -3.0383621
-3 -2.0332036
-1 7.9264764
-2 -1.6644901
-2 -2.0889531
-5
-6
-6
-6
-6
-6
-6
-6
-5
5.0020496
2.5877458
9.6963832
-10
2.3636365
-10
-6 1.8827643
-11
-7 -3.0096280
-10
-6 -8.9155491
-10
-6 -8.6286756
-10
7.4284923
6.5568964
1.8540516
1.6260416
-9
-9
-11
-12
-10
-11
-5 -1.3187245
-8
-5 -8.3062870
-10
3
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
-0.01 to +0.01
Error
Range (µV)
Exact-
Approx.
-7 to 15
-16 to 12
-35 to 25
-55 to 35
-65 to 35
-.4 to .5
-1.7 to 1.6
-2.1 to 1.8
-.05 to .05
-.05 to .05
-.05 to .05
-.05 to .05
-1.0 to 1.3
-.05 to .05
Type R
Thermocouples
4
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Error
Range (¡C)
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-50 to 900
0 to 1100
0 to 1400
0 to 1650
0 to 1768
400 to 1100
400 to 1400
400 to 1650
1050 to 1400 -4.1134459
1050 to 1650
1400 to 1550
1400 to 1650
1400 to 1768
1666 to 1768
4.5509556
4.9160016
4.8343651
3.7487318
8.0559850
1.4180146
3.1758093
1.2883437
1.6251434
1.5239494
1.4441607
1.3944190
+1
+1
+1
+0
+1
+1
+2
1.3752883
1.1284875
1.1054589
1.1098270
1.2738464
1.1519304
1.0442877
9.0181346
+3 -5.8922431
+4 -2.6747958
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-2
-1
+0
-2.0454379
-1.3755675
-9.5014952
-7.4485484
-6.7651171
-2.8603978
-2.3559046
-2.4353890
-4.3132296
-2.9827002
-1.9827500
-7.4068329
5.6190639
2.2334214
-5
-5
-6
-6
-6
-6
-6
-6
2.5404935
1.2610922
-9 -1.1767904
-13
-9 -4.4281251
-14
6.2073358
-10 -1.5622497
-14
3.8266182
-10 -7.4517277
-15
3.1420473
-10 -5.4254872
-15
8.5173702
-11 -1.1440038
-15
3.9276248
-11
4.5164488
-11
3.3369324
1.8172612
-16
-16
Exact-
Approx.
-13 to 3
-4 to 7
-6 to 10
-7 to 13
-7 to 14
-.04 to .04
-.08 to .09
-.10 to .12
-6
-6
1.3863582
-10 -1.5283798
-15
7.4538667
-11 -3.7809957
-16
-6 3.3603790
-11
-7 -1.4487255
-11
2.4513433
9.4290495
-16
-16
-.002 to .002
-.011 to .011
-.0005 to .0005
-.0005 to .0005
-5 -2.1303241
-4 -8.0565860
-9
-9
3.0369250
-14 -.11 to .08
1.0882779
-13 -.0007 to .0007
4
Quartic approximations to the data as a function of voltage in selected temperature ranges (¡C).
The expansion is of the form T = a
0
+ a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
B-3
Thermocouple Conversion Tables
Type B
Thermocouples
5
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
0 to 900
0 to 1100
0 to 1400
0 to 1650
0 to 1820
400 to 1100 1.3740347
400 to 1400 -2.5321108
400 to 1650 -1.1708354
1050 to 1400 -9.8446259
1050 to 1650
1400 to 1550
-1.3702395
-4.7644591
1400 to 1650 -6.4878929
Reference
Junction
Correction
0 to 50
+2
+3
+2
+2
-2.3614224
-2.3893338
-2.3476301
-1.9185893
-1.3749133
+1 -3.2914888
+1 -9.9736579
+2 3.9860894
3.3670688
4.6252371
2.2890832
2.7380621
-2.4673839
-1
-1
-2
-1
-1
-1
-1
-1
-1
5.7496551
5.7684447
5.7480761
5.5578879
5.3446673
5.9766638
5.4976533
4.5539656
+0 8.2282215
+0 -7.0976836
+0
+0
1.5749253
1.1375302
5.9050303
-3 -5.6339756
-3 -5.9963692
-3 -5.7165679
-3 -3.3057924
-3 -9.1094186
-3 -8.0141311
-3 -3.7806912
-3
-4
-4
-3
-3
-3
3.6623964
2.4061224
3.2325686
2.2417410
2.4305578
-1.2267180
-7
-7
-7
-7
-8
-7
-7
-7
-6
-6
-6
-6
-6
-1.1808558
-9.7041131
-1.0838193
-2.0018428
-2.8098361
-2.7203972
-1.6156824
-3.6969100
-7.7901142
-9.4548852
-7.8471224
-8.1518033
-10
-11
-10
-10
-10
-11
-10
-10
-10
-10
-10
-10
5
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
-0.01 to +0.01
Error
Range (µV)
Exact-
Approx.
-.22 to .14
-.18 to .20
-.7 to 1.0
-4 to 5
-8 to 9
-.05 to .05
-.5 to .5
-2.0 to 1.8
-.05 to .05
-.05 to .05
-.05 to .05
-.05 to .05
Type B
Thermocouples
6
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
0 to 900
0 to 1100
0 to 1400
0 to 1650
0 to 1820
400 to 1100
400 to 1400
400 to 1650
1050 to 1400
1050 to 1650
1400 to 1550
1400 to 1650
1.8946288
2.0949015
2.2354664
3.2188156
3.4418084
3.7140306
3.9253848
+2
+2
+2
+2
+2
+2
+2
8.9244743
7.2874066
5.7822214
4.9929130
4.6255054
3.0966136
2.7222162
2.4988761
1.8282378
1.7031473
1.5828913
1.4979551
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-5.7447033
-3.1771931
-1.6039309
-1.0349686
-8.2176262
-5.8100680
-3.6930932
-2.7160312
-1.1561743
-8.9696912
-7.0050689
-5.7276293
-4
-4
-4
-4
-5
-5
-5
-5
-5
-6
-6
-6
1.8053618
6.8254996
2.2187592
1.0792281
7.3717195
8.2483967
3.6830239
2.1299660
-7
-8
-8
-8
-9
-9
-9
-9
-1.9719121
-5.1002233
-1.0678514
-3.9111456
-2.2913665
-4.7591774
-1.4483702
-6.4220755
-11
-12
-12
-13
-13
-13
-13
-14
6.4320083
-10 -1.4544375
-14
4.0789445
-10 -6.6410259
-15
2.6714849
-10 -2.9082072
-15
1.8192801
-10 -7.8042686
-16
6
Quartic approximations to the data as a function of voltage in selected temperature ranges (¡C).
The expansion is of the form T = a
0
+ a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (¡C)
Exact-
Approx.
-30 to 75
-35 to 90
-45 to 110
-50 to 120
-50 to 130
-.09 to 1.0
-3 to 3
-5 to 5
-.003 to .003
-.025 to .020
-.001 to .001
-.001 to .001
B-4
Thermocouple Conversion Tables
Type E
Thermocouples
7
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-270 to 0
-200 to 0
-200 to 800
-20 to -500
0 to 400
0 to 1000
400 to 1000 -8.5384268
600 to 800 -1.3839633
850 to 1000 -5.1503130
Reference
Junction
Correction
0 to 50
+2
+3
5.9287179
5.8754764
5.8043714
5.8318735
5.8327591
5.8734597
6.5022632
6.7211126
+4 -1.6691278
5.8637565
+1
+1
+1
+1
+1
+1
+1
+1
+2
+1
7.0983783
5.7443085
5.6118501
5.4292960
5.3761106
5.0789891
3.4354900
3.1669230
4.1877018
4.6720025
-2
-2
-2
-2
-2
-2
-2
-2
-1
-2
5.2421843
-5.0637772
-5.9506584
-5.6288941
-5.2870656
-4.7821793
-2.9769494
-2.9237913
-3.1228607
-1.4438022
-5
-5
-5
-5
-5
-5
-5
-5
-4
-5
3.8137875
1.3960921
2.2327737
2.0825828
1.5352840
1.4659118
7.6039401
8.1514671
8.5283044
-8
-8
-9
-9
-8
-7
-7
-8
-8
7
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (µV)
Exact-
Approx.
-5 to 5
-.5 to .4
-60 to 30
-8 to 4
-3 to 4
-18 to 17
-2 to 2.5
-.03 to .03
-.06 to .06
-.12 to +.24
Type E
Thermocouples
8
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Error
Range (¡C)
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-270 to 0
-200 to 0
-200 to 800
-20 to 500
0 to 400
0 to 1000
400 to 1000
600 to 800
850 to 1000
1.9669452
2.5192188
-7.1102114
+1
+1
+2
2.8168878
1.5726646
1.8432856
1.6970287
1.7022525
1.6410783
1.4207735
1.3909529
5.6554599
-3
-2
-2
-2
-2
-2
-2
-2
-2
-8.5940057
-1.2102152
-3.2311582
-2.0830603
-2.2097240
-1.3560189
-5.1844510
-4.7201133
-9.7013068
-6 -1.4930918
-9 -8.7987588
-14
-6 -1.9577799
-10 -1.6696298
-14
-7
-7
-7
-7
-8
-8
-7
6.9795810
4.6512717
5.4809314
1.8600342
-12
-12
-12
-12
-5.1106852
-4.1805785
-5.7669892
-8.5537337
-17
-17
-17
-18
Exact-
Approx.
-9 to 6
-.3 to .3
-8 to 7
-.18 to .12
-.05 to .04
-.9 to 1.4
5.6361365
-13 -1.5646343
-18 -.03 to .03
5.5638718
-13 -1.7775228
-18 -.0005 to .0005
9.3938146
-12 -3.3333675
-17 -.001 to .001
8
Quartic approximations to the data as a function of voltage in selected temperature ranges (¡C).
The expansion is of the form T = a
0
+ a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
B-5
Thermocouple Conversion Tables
Type J
Thermocouples
9
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-200 to 0
-200 to 760
-200 to 1200
-20 to 500
0 to 400
0 to 760
0 to 1200
400 to 760
400 to 1200
600 to 760
760 to 1200
Reference
Junction
Correction
0 to 50
-5.7931005
7.1127371
-2.5724435
3.9064962
5.0408743
4.9502533
4.7062907
5.0465304
5.0452399
5.1258213
+3
+3
+4
5.5861877
9.7718575
1.8969007
2.2157898
+4 -1.4765017
5.0373743
+1
+1
+1
+1
+1
+1
3.2009063
3.2898022
2.5522650
2.8062596
2.8409137
2.0040854
+1 -1.4207954
+1 -1.1658430
+1
+2
+2
+1
5.3862730
-4.0418097
3.6470921
3.0167011
-2 -6.3493968
-2 -6.9936031
-2 -2.2198295
-2 -6.5666305
-2 -6.7556436
-2 -4.2235982
-2
-1
-2 -2.2171472
-1
-1
-2
3.1325181
1.3184454
4.2749984
-2.7029005
-7.4293513
-5
-5
-5
-5
-5
-5
-5
-4
-4
-5
2.5174022
5.1112729
7 1373907
5.3587106
5.6382040
3.2819408
-5 -1.5023710
-4 -4.8218788
-8
-8
-8
-8
-7
-8
-9
-8
1.8445398
-10
1.6174242
-7
7.2113090
-8
9
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (µV)
Exact-
Approx.
-.2 to .3
-100 to 80
-500 to 600
-1.5 to 3.0
-.8 to .5
-24 to 36
-210 to 160
-2.5 to 2.8
-110 to 100
-.1 to .1
-11 to 11
-.06 to +.06
Type J
Thermocouples
10
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-200 to 0
-200 to 760
-200 to 1200
-20 to 500
0 to 400
0 to 760
0 to 1200
400 to 760 9.2808351
400 to 1200 -1.1075293
600 to 760 1.8020713
760 to 1200 -6.3828680
+1
+2
+2 -4.5284199
+2
1.8843850
2.1155170
2.1676850
1.9745056
1.9750953
1.9323799
1.8134974
5.4463817
2.8651303
7.4068749
-2 -1.2029733
-2 -3.3513149
-2 -2.1844464
-2 -1.8094256
-2 -1.8542600
-2 -1.0306020
-2 -5.6495930
-3
-2
-3
-2
6.5254537
-2.9758175
1.0769294
-1.7177773
-6 -2.5278593
-10 -2.5849263
-14
-7
-7
-7
-7
-7
-7
-6
1.2443997
3.9094347
7.8777919
2.1771293
-11
-12
-12
-11
-1.5227150
-2.4303017
-1.1897222
-9.9502571
-16
-17
-16
8.3683958
-12 -1.3280568
-16
3.7084018
-12 -5.1031937
-17
-8 -2.4644023
-12
-7 -1.3987013
-11
2.1141718
9.9364476
-17
-17
2.5945419
-12 -4.9012035
-18
-6 -2.1962321
-11 1.5521511
-16
-17
10
Quartic approximations to the data as a function of voltage in selected temperature (¡C).
The expansion is of the form T = a
0
+ a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (¡C)
Exact-
Approx.
-.4 to .5
-6 to 7
-14 to 10
-.07 to .06
-.03 to .05
-.9 to .7
-3 to 4
-.03 to .03
-1.3 to 1.6
-.001 to .001
-.15 to .11
B-6
Thermocouple Conversion Tables
Type K
Thermocouples
11
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-270 to 0
-200 to 0
-200 to 800
-20 to 500
0 to 400
0 to 1370
400 to 1000 1.3223524
400 to 1370 -3.5456236
600 to 800 2.1326086
850 to 1000 -9.0373549
1050 to 1150 -2.5972816
Reference
Junction
Correction
0 to 50
+3
+1
+3
+2
+3
3.9575518
3.9478446
3.6762217
4.0999640
4.0981103
3.9443859
3.0191663
3.8349319
2.5608012
4.0577145
5.2075276
3.9448872
+1
+1
3.1063355
2.8256412
+1 2.4544587
+1 -3.2619221
+1 -1.5992510
+1 5.8953822
+1
+1
+1
+1
+1 -1.4576419
+1
2.7508912
9.9993329
3.7091744
9.5092149
2.4548362
-2 -9.1607995
-2 -1.1488433
-2 -4.3081993
-3
-4 -1.2525700
-3 -4.2015132
-2 -2.4734437
-3 -8.7444446
-2
-3
-2
-2
8.5714137
-3.3517324
-1.0989249
9.4854151
-9.0918433
-5
-6
-5
-6
-5 3.0006628
-4 -2.8153447
-5 2.5127588
-6 -1.6912373
-5
-5
-5
3.2784725
1.3917059
6.9799332
1.7108618
9.9607405
3.0753213
-6 -3.1178779
-9
-9
-9
-8
-8
-8
-9
-8
-10
-9
-9
11
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (µV)
Exact-
Approx.
-1.1 to 1.2
-.08 to .05
-180 to 200
-25 to 45
-25 to 20
-60 to 110
-.9 to 1.4
-12 to 11
-.05 to .07
-.05 to .03
-.05 to .05
-.06 to +.14
Type K
Thermocouples
12
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Error
Range (¡C)
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-270 to 0
-200 to 0
-200 to 800
-20 to 500
0 to 400
0 to 1370
400 to 1000 -2.4707112
400 to 1370 6.2300671
600 to 800 -3.9480992
850 to 1000 -3.1617495
1050 to 1150 2.3615582
+1
+0
+1
+0
+2
1.2329875
2.3783697
2.8346886
2.4363851
2.4383248
2.5132785
2.9465633
2.4955374
3.1425797
2.7115517
1.1066277
-2 -1.4434305
-2 -2.4382217
-2 -5.8008526
-2
-2
5.6206931
9.7830251
-2 -6.0883423
-2 -3.1332620
-2 -7.8788333
-2
-2
-3
-4.0905633
-2.1941995
8.2516607
-5 -4.2824995
-9 -4.2028679
-13
-6 -6.8203073
-10 -9.4854031
-14
-7 2.5720615
-11 -3.6813679
-16
-8 -3.8825620
-12 3.9120208
-17
-9
-8
-7
-8
3.6276965
5.5358209
-12
-13
6.5075717
-12 -3.9663834
-17
1.3269743
-12
-2.5756438
9.3720918
1.5580541
-16
-18
-18
Exact-
Approx.
-11 to 8
-.5 to .5
-8 to 10
-1.2 to .6
-.5 to .6
-2.4 to 1.2
-.02 to .02
-.3 to .3
-7
-7
8.5482602
-12
-7 -1.3558849
-11
-5.5696636
4.8782826
-12 -2.9316611
-17 -.0012 to .0012
9.1638500
-17
-17
-.001 to .001
-.001 to .001
12
Quartic approximations to the data as a function of voltage in selected temperature ranges (¡C).
The expansion is of the form T = a
0
+ a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
B-7
Thermocouple Conversion Tables
Type T
Thermocouples
13
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-270 to 0
-200 to 0
-200 to 400
0 to 400
Reference
Junction
Correction
0 to 50
3.9439919
3.8749056
3.8621703
3.8468407
3.8709457
+1
+1
+1
+1
+1
6.2407452
4.5149809
4.5433050
4.6651731
3.7085566
-2
-2
-2
-2
-2
8.0773568
4.7759448
-3.4731838
-3.7375793
5.6495520
-5
-5 -2.5773959
-5
-5
-5
2.6845647
1.4661300
1.5999833
-7
-8
-8
-8
13
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form E = a
0
+ a
1
T + a
2
T
2
+ a
3
T
3
+ a
4
T
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (µV)
Exact-
Approx.
-9 to 7
-.14 to .13
-7 to 3.5
-.9 to .9
-.1 to .1
Type T
Thermocouples
14
Temperature
Range (¡C) a
0 a
1 a
2 a
3 a
4
Quartic Equation Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
Argument Exp.
-270 to 0
-200 to 0
-200 to 400
0 to 400
4.3553379
2.3837090
2.6792411
2.5661297
-3
-2
-2
-2
-2.0325426
-2.9878839
-1.0370271
-6.1954869
-5 -5.4720813
-6 -7.1945810
-10 -1.0041943
-13
-6
-7
6.1330327
2.2181644
-9 -5.0865527
-13
-11
-11
-1.3988385
-3.5500900
-15
-16
14
Quartic approximations to the data as a function of temperature (¡C) in selected temperature ranges.
The expansion is of the form T = a0 + a
1
E + a
2
E
2
+ a
3
E
3
+ a
4
E
4
where E is in microvolts and T is in degrees Celsius.
Error
Range (¡C)
Exact-
Approx.
-8 to 6
-.3 to .3
-6 to 5
-.15 to .17
B-8
Index
B
Basic front panel operation 3-18
C
Calibration with thermistor probe 4-10
Calibration with thermocouple wire 4-11
Card connections and installation 2-1
Card installation and removal 2-10
Closing and opening channels 3-9
Component layout and schematic diagram 5-1
Configure channels (CONFIG-CHAN) 3-4
Configure stepping and scanning 3-18
D
E
F
Front panel scanner controls 3-2
M
Measurement considerations 3-30
G
O
Open and close channels (CHAN) 3-2, 3-19
Output connections to multimeter 2-12
H
Handling and cleaning precautions 4-1
Handling precautions 1-2, 2-1, 4-1
I
IEEE-488 bus scanner commands 3-6
IEEE-488 programming example (temperature
P
K
i-1
R
Radio frequency interference (RFI) 3-32
Resistor temperature coefficient testing 3-28
RTD temperature measurements 3-13
T
Temperature measurements 3-11, 3-20
Temperature measurement configuration 3-21
Temperature measurement procedure 3-21
Thermocouple conversion tables B-1
Thermocouple measurement error sources 3-30
Thermocouple measuring example A-2
Thermocouple measuring procedure A-2
Thermocouple temperature measurements 3-11
Troubleshooting equipment 4-14
Troubleshooting procedure 4-15
Typical connecting schemes 2-6
S
Scan configuration (CONFIG-SCAN) 3-5
Scanner card installation 2-10
Scanner card modification 4-15
Special handling of static-sensitive devices 4-13
Start stepping or scanning 3-20
U
Using EXIT to stop scanning 3-6
Using RTD and thermocouple sensors together
Using SCAN to configure scan parameters and
V
W
i-2
Service Form
Model No.
Name and Telephone No.
Company
Serial No.
List all control settings, describe problem and check boxes that apply to problem.
Date
❏
Intermittent
❏
❏
IEEE failure
Front panel operational
❏
Analog output follows display
❏
❏
Obvious problem on power-up
All ranges or functions are bad
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Particular range or function bad; specify
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Batteries and fuses are OK
Checked all cables
Display or output (check one)
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Drifts
Unstable
Overload
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Unable to zero
Will not read applied input
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Calibration only
Data required
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CertiÞcate of calibration required
(attach any additional sheets as necessary)
Show a block diagram of your measurement system including all instruments connected (whether power is turned on or not).
Also, describe signal source.
Where is the measurement being performed? (factory, controlled laboratory, out-of-doors, etc.)
What power line voltage is used?
Ambient temperature?
Relative humidity?
Other?
Any additional information. (If special modiÞcations have been made by the user, please describe.)
¡F
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Key Features
- Built-in reference junction
- Low contact potential
- Input connectors are in contact with an isothermal block
- Nine channels of 2-pole relay input
- Four channel pairs configurable for 4-pole operation
- Multiplex one of nine 2-pole, or one of four 4-pole channels into the DMM
- Thermocouple accuracy