Model DT3000 Oxygen Analyzer

Model DT3000 Oxygen Analyzer
Model DT3000
O2 Oxygen Analyzer
This Manual Covers The Following systems:
Panel Mount
Rack Mount
Insitu
Extractive
Version 1.17
Model DT3000 Oxygen Analyzer
Version 1.17
Table of Contents
INTRODUCTION ................................................................................................................................................5
SPECIAL NOTE FOR INSITU SYSTEMS.......................................................................................................6
SECTION 1 ...........................................................................................................................................................7
ANALYZER OVERVIEW................................................................................................................................7
1.1
Configurations covered by this manual ..........................................................................................7
1.2
Analyzer Description ......................................................................................................................7
1.3
Theory of Operation .......................................................................................................................7
1.4
Electronic Controller......................................................................................................................8
1.5
Standard Analyzer Features ...........................................................................................................8
SECTION 2 .........................................................................................................................................................10
SPECIFICATIONS..........................................................................................................................................10
2.1
ANALYZER ...................................................................................................................................10
2.2
DETECTOR ..................................................................................................................................11
2.3
SAMPLE ......................................................................................................................................11
OUTPUTS ...................................................................................................................................................11
2.4
CALIBRATION .............................................................................................................................12
2.5
ALARM .........................................................................................................................................12
2.6
GASES ..........................................................................................................................................12
SECTION 3 .........................................................................................................................................................14
INSTALLATION ............................................................................................................................................14
3-1
OVERVIEW: .................................................................................................................................14
3.2
INSTALLATION............................................................................................................................14
3.3
PNEUMATIC CONNECTIONS....................................................................................................16
SECTION 4 .........................................................................................................................................................18
PARAMETERS DEFINITIONS .....................................................................................................................18
4.1
INTRODUCTION .........................................................................................................................18
4.2
BACK PURGE PERIOD...............................................................................................................18
4.3
BACK PURGE DURATION .........................................................................................................18
4.4
ROLLING AVERAGE ...................................................................................................................18
4.5
INSTANT AVERAGE ....................................................................................................................18
4.6
RECORDER RANGE....................................................................................................................19
4.7
O2 LOW ALARM SETPOINT .......................................................................................................19
4.8
HIGH ALARM SETPOINT ...........................................................................................................19
4.9
CAL PURGE TIME ......................................................................................................................20
4.10
SAMPLE & HOLD IN CAL ..........................................................................................................20
4.11
AUTO CALIBRATION..................................................................................................................20
4.12
SET TIME HH:MM ....................................................................................................................20
4.13
COMMS. SETUP ..........................................................................................................................20
SECTION 5 .........................................................................................................................................................21
UTILITIES DESCRIPTION............................................................................................................................21
5.1
INTRODUCTION .........................................................................................................................21
5.2
SIGNALS.......................................................................................................................................22
5.3
OUTPUTS.....................................................................................................................................22
5.4
DIGITAL IN..................................................................................................................................22
5.5
O2 CLAMP ...................................................................................................................................23
SECTION 6 .........................................................................................................................................................24
STARTUP AND OPERATION.......................................................................................................................24
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Model DT3000 Oxygen Analyzer
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6.1
6.2
6.3
6.4
INTRODUCTION .........................................................................................................................24
INITIAL STARTUP .......................................................................................................................24
SET UP PROCEDURE.................................................................................................................24
SETTING PARAMETERS .............................................................................................................25
SECTION 7 .........................................................................................................................................................35
CALIBRATION ..............................................................................................................................................35
7.1
INTRODUCTION .........................................................................................................................35
7.2
CALIBRATION .............................................................................................................................35
7.5
ZERO AND SPAN CHECK ..........................................................................................................37
7.7
ABORT TECHNIQUES FROM CALIBRATION...........................................................................37
SECTION 8 .........................................................................................................................................................38
DIAGNOSTIC DISCUSSION.........................................................................................................................38
8.1
INTRODUCTION .........................................................................................................................38
8.2
CALIBRATION FAULT ................................................................................................................38
8.3
HIGH SENSOR TEMP .................................................................................................................38
8.4
LOW SENSOR TEMP ...................................................................................................................38
SECTION 9 .........................................................................................................................................................40
INSTRUMENT DESCRIPTION.....................................................................................................................40
9.1
INTRODUCTION .........................................................................................................................40
9.2
O2 CELL ANALOG CIRCUIT.......................................................................................................40
9.3
O2 CELL THERMOCOUPLE CIRCUIT ......................................................................................40
9.4
RELAY OUTPUTS ........................................................................................................................40
9.5
INPUTS.........................................................................................................................................41
SECTION 10 .......................................................................................................................................................42
OXYGEN SENSOR ........................................................................................................................................42
10.1
OXYGEN SENSOR - GENERAL...................................................................................................42
10.2
ZIRCONIA SENSOR ASSEMBLY.................................................................................................42
SECTION 11 .......................................................................................................................................................43
TROUBLE SHOOTING..................................................................................................................................43
11.1
OVERVIEW ..................................................................................................................................43
11.2
SPECIAL TROUBLESHOOTING NOTES ...................................................................................43
11.3
SENSOR TROUBLESHOOTING..................................................................................................43
11.4
ELECTRONICS TROUBLESHOOTING ......................................................................................45
11.5
ALARM MESSAGES.....................................................................................................................46
SECTION 12 .......................................................................................................................................................47
SERVICE AND NORMAL MAINTENANCE ...............................................................................................47
12.1
OVERVIEW ..................................................................................................................................47
12.2
PRELIMINARY CHECKS.............................................................................................................47
12.3
SENSOR CALIBRATION: ............................................................................................................48
12.4
SENSOR REMOVAL AND INSTALLATION: ...............................................................................48
12.5
HEATER ELEMENT REPLACEMENT ........................................................................................49
12.7
SPARE PARTS..............................................................................................................................49
13
WARRANTY........................................................................................................................................50
13.1
14
RETURNING EQUIPMENT TO THE FACTORY ........................................................................50
MODBUS REGISTERS ......................................................................................................................52
APPENDIX I – DRAWINGS FOR INSITU UNIT, PANEL MOUNT CONTROL UNIT ..........................54
APPENDIX II – DRAWINGS FOR INSITU UNIT, NEMA 4 CONTROL UNIT .......................................59
APPENDIX III – DRAWINGS FOR EXTRACTIVE RACK MOUNT CONTROL UNIT........................61
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Model DT3000 Oxygen Analyzer
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APPENDIX III – DRAWINGS FOR EXTRACTIVE RACK MOUNT CONTROL UNIT........................62
APPENDIX IV – DRAWINGS FOR SELF CONTAINED CONTROL UNIT ............................................66
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Model DT3000 Oxygen Analyzer
Version 1.17
Introduction
This manual contains instructions for the operation and programming of a DT3000
Oxygen analyzer.
This analyzer has two basic designs:
Insitu System – This refers to an installation where the probe for collecting
the gas sample has the Oxygen sensor (O2 Head) as an integral part of the
probe. This is typically used on a positive or neutral (where an eductor is
added) pressure stack or duct and the sample is forced through the sample
line to the control unit.
Extractive System – This refers to an installation where the probe for
collecting the gas sample is separate from the Oxygen sensor. This is
typically used on a negative pressure stack or duct where the sample is
drawn through the sample line by a vacuum pump.
In addition to the different designs, there are different control configurations:
Panel Mount Control – This configuration houses the control system only
and is typically used with the Insitu design. However it could be used where
the extractive Oxygen sensor and probe are remotely located.
NEMA 4 Control - This configuration houses the control system only in a
NEMA 4 rated wall mount cabinet, and is typically used with the Insitu design.
However it could be used where the extractive Oxygen sensor and probe are
remotely located.
Rack Mount Control - This configuration houses the control system and the
Oxygen sensor (O2 Head) on a 19” rack mount panel, and is typically used
with the Extractive design. The pump is located elsewhere.
Self Contained Control – The self contained control is an Extractive system
where the control, vacuum pump and Oxygen sensor are all located in a
single NEMA 4 wall mount cabinet.
Drawings of these various configurations are located in the Appendix of this manual.
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Model DT3000 Oxygen Analyzer
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Special Note for Insitu Systems
The Insitu DT3000 is based on gas be presented to the Oxygen sensor
(O2 Head) sensor. There may be circumstances that exist where the
gas to be measured does not reach the sensor (in a neutral pressure
duct, for instance). For those circumstances a stainless steel eductor
(see drawing DT3000-07) has been supplied with your DT3000 system.
An eductor is a device that produces suction when air is introduced into
it. This suction draws the flue gas up the probe and insures it
presentation to the sensor.
If the system calibrates properly but the O2 reading from the gas being
monitored drifts aimlessly in the higher percentile range, install the
eductor in the system.
Section 2 of the manual has air pressure versus sample flow rates for
correct flow adjustment.
Plant air can be used to feed the eductor but instrument grade air is
recommended for maintenance free operation of the eductor.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 1
ANALYZER OVERVIEW
1.1
Configurations covered by this manual
Insitu
Extractive
Panel Mount
NEMA 4 Mount
Rack Mount
1.2
Analyzer Description
The Datatest Model DT3000 Oxygen Analyzer is designed for continuous
measurement of Oxygen concentration in a non-combustible or low-level
combustible flowing gas sample. The Model DT3000 reflects the state of the
art in detector and electronic hardware design. For extractive O2 systems
using a sampling system (user provided), sample gas is piped to a Zirconia
sensor mounted in the O2 Head. The O2 Head can either be mounted in the
analyzer unit (Controller), or remotely mounted. For Insitu O2 systems, the
sensor is located directly on the probe in the stack or duct.
The electronic package incorporated within the DT3000 features
microprocessor technology that greatly expands the versatility and
capabilities of the Oxygen Analyzer.
The display prompts the operator during the set-up routines, shows instant
and average concentration of sample, high and low alarm set points, recorder
range, and more. A standard Modbus RTU (RS232, or 485, or 422)
communication port is also provided to allow two-way communication with
data acquisition systems.
The 16-key keypad provides a completely sealed keyboard to assure that its
touch-sensitive contacts are not subject to dust or moisture.
1.3
Theory of Operation
The measurement of oxygen is accomplished by reading voltage developed
across a heated Zirconia cell that is induced by uneven concentrations of
oxygen. The O2 sensor consists of a Zirconia Cell, which is coated with
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Model DT3000 Oxygen Analyzer
Version 1.17
porous metal electrodes. The sample gas is supplied to the sample side of
the cell by an external source and reference air (ambient air) is provided to
the opposite side of the cell.
Electronic temperature control maintains proper cell temperature.
For best results, supply the analyzer with clean, dry, instrument air (20.95%
oxygen) as a reference gas. With the sensor at its operating temperature,
and unequal oxygen concentrations across the cell, oxygen ions travel from
high partial pressure side to low partial pressure side. This characteristic
enables the oxygen analyzer to provide exceptional sensitivity at low oxygen
concentration.
WARNING
Do not use this analyzer on flammable samples, use explosion-proof
version for analysis of flammable samples. If used for analysis of
explosive gases, internal leakage of sample could result in explosion
causing death, personal injury, or property damage.
The DT3000 Oxygen Analyzer measures net oxygen concentration in the
presence of all products of combustion, including water vapor. There the
analysis is made on a ‘wet’ gas basis.
1.4
Electronic Controller
The DT3000 microprocessor controller electronically controls sensor
temperature, heater power, display measurements, functions, and provides
isolated analog outputs that are proportional to measured oxygen
concentrations. Normally open (N.O.) relay contacts are provided for low and
high alarm set points, zero, span calibration, back purge, and system fault.
Temperature of the oxygen cell is maintained constant by modulating the duty
cycle of the sensor’s heater. The electronics accepts millivolt signal
generated by the sensing cell and converts this voltage signal to an analog
isolated 4-20mA current output to be used by remotely connected recording
devices.
1.5
Standard Analyzer Features
1. Recalibration through a 16-key tactile feedback membrane keyboard.
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Model DT3000 Oxygen Analyzer
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2. Prompts on a 4-line by 20-character LCD display help an operator during
the various set-up routines (such as for concentration of sample, average
concentration, alarms levels, etc.).
3. Standard RS-232/485/422 ports (unit ships in RS232 configuration) to
allow bi-directional communication with other data acquisition systems.
4. Completely sealed keyboard for reliable long term operation.
5. Alarm indications of fault conditions with independent set points alarms.
6. Standard isolated current (4-20mA) outputs.
7. Continuous monitoring of the sensor’s condition.
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Model DT3000 Oxygen Analyzer
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SECTION 2
SPECIFICATIONS
2.1
ANALYZER
Standard Measurement Ranges
Measures O2 from 0-25% adjustable
Analog Outputs
Standard 4-20 mA
Analyzer Method
Insitu and Extractive
Detector Type
Zirconia
Accuracy
Linear: 0-10% +/- 0.1% F.S.
0-25% +/- 0.25% F.S.
Response Time
5 seconds (95%) step input at inlet
Sensitivity
0.1% (25% Scale) F.S.
Display
4-Line by 20 Character Backlit LCD
Supply Voltage
115/220 VAC +/- 10% at 50/60 Hz.
Ships standard at 115 volts
Power Consumption
100 Watts at 115 VAC, 50/60 Hz.
Enclosure
19” Rack Mount or NEMA 4 Wall Mount
or Panel Mount (standard)
Alarm Set Points
0-25% O2 user selectable
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Model DT3000 Oxygen Analyzer
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2.2
DETECTOR
Type
Zirconia
Temperature
1000°F. Controlled by microprocessor
with readout on LCD Display
2.3
SAMPLE
Sampling Rate Extractive
System
Sampling Rate
Insitu System
Response Time
Approximately 5.0 SCFH (473 cc/min)…. Note.
For Extraction using and eductor:
Assuming sample and air lines are ¼’ tube:
Air Pressure of 5/10/15 Psi will pull a sample of
3.5/7/10 SCFH
Should the probe be situated in an area where
the pressure at the sensor is inadequate, The use
of an eductor, supplied as standard with your
Datatest Probe will allow you to overcome this
negative pressure and pull the gas from the
stream, up the probe, and allow it to be presented
to the sensor. The vent hole at the top of the
probe must remain plugged when using an
eductor. Some guidelines for eduction are as
follows:
Assuming air lines are ¼’ tube, air Pressure of
5/8/10/12 psi will pull a sample of 3/5/5.5/7 SCFH
95% of full scale within 5 seconds
OUTPUTS
LCD Display
4-line by 20 character LCD
Analog
4-20mA
Serial Ports
RS-232/459/422 to a computer for bi-directional
communication. RS232 ships as standard
Relay Outputs (N.O.
SPST, 1A)
System alarm, Back Purge, O2 low, O2 high, Zero,
and Span
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Model DT3000 Oxygen Analyzer
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2.4 CALIBRATION
External
Standard calibration procedure
permits the introduction of zero and
span gases through the sample
port.
Cal Gas Target Values
Standard zero and span values
entered via keypad.
Frequency
Via external digital (potential free)
inputs
Recommended Calibration Gas
Mixture
Zero: 2% O2, Balance N2; Span:
8% O2, Balance N2
Recommended Calibration Gas
Flow Rate
5.0 SCFH (473 cc/min)
2.5 ALARM
Concentration
0-25%, user selectable
System
Denotes a system failure.
Internal
Audible 60 dB alarm
External
N.O. SPST Relay Contacts, 10 Amp
AC/DC
Alarm Condition
Reported to screen, and
communications output port.
2.6 GASES
Reference Air
No more than 1 SCFH at .1 psig
required.
Ports
1/4” tubing connections
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Model DT3000 Oxygen Analyzer
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2.7 SAMPLE PROBES
Probe Material / Gas Temperature
316 Stainless Steel or Inconel.
Standard: 1,500°F (815°C) max.
Alumina (High Temp) - Optional
2,800°F (1538 °C) max
Probe Length
Standard: 2 feet. Optional: up to 9
feet.
Flange
Stainless steel 304, ANSI #125,
Insitu: 4”
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 3
INSTALLATION
3-1
OVERVIEW:
This section covers the installation of the Model DT3000 Oxygen Analyzer.
When installing, observe the following precautions.
a. Do not operate this analyzer in an explosive atmosphere.
b. The control unit mounting location must be dry and not exposed to
freezing temperatures. Formation of condensation must be avoided.
Do not place the control cabinet in direct sunlight.
c. Ambient temperatures must be between 32°F and 112°F (0°C and
45°C). If the analyzer is used outside its operating range, accuracy
and error limit cannot be guaranteed.
d. Eliminate vibrations. Structural vibrations, machinery vibrations, etc.
will affect the operation and life of the analyzer. Find a vibration free
structural wall or a similar place for firm mounting of the controller.
e. If the unit is to be extractive, mount the analyzer as close to the
sampling point as possible. This will reduce dead time. If a suitable
installation place cannot be found close enough, the dead time due to
longer lines can be made up by a higher sampling delivery rate.
f. All wiring must be in accordance with national and local wiring codes.
3.2
INSTALLATION
Mechanical Installation
The O2 Analyzer control unit requires installation in a location where the
temperature range is between 32°F and 112°F (0-45°C).
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Model DT3000 Oxygen Analyzer
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Electrical Connections: See Appendix for drawings.
1. Power input: 115 or 220 VAC, +/-10%, single phase, 50 or 60 Hz,
250 watts maximum.
2. The power cable should comply with the safety regulations in the
user’s country and should never be smaller than 12 AWG (14 SWG).
3. ANALOG SIGNALS: The Model DT3000 has standard 4-20mA
current outputs. The current outputs are calibrated for a 250-ohm load.
This output signal can be fed to an external load such as a recorder, or
the signal can be used to drive a single external meter or recorder, as
desired.
4. RS-232/422/485 CONNECTIONS: The Model DT3000 is equipped
with a serial port that can be configured for RS-232 or RS-422 or RS485. This allows the Model DT3000 to report its data to a DCS or
other computer via a Serial Modbus RTU Protocol.
5. DIGITAL INPUTS: There are several digital inputs on the Model
DT3000. These inputs permit external devices to initiate zero and
span checks. A will initiate a zero calibration and a 120 Vac input to
TB1/2 will initiate the span.
6. RELAY OUTPUTS: Several relay outputs are available on the rear
panel TB1, terminal strip. They are:
TB1
10
11
12
13
14
15
16
17
18
19
20
21
DESCRIPTION
System Fault
System Fault
Back Purge
Back Purge
O2 Low Alarm
O2 Low Alarm
O2High Alarm
O2 High Alarm
Zero Cal Solenoid Valve
Zero Cal Solenoid Valve
Span Cal Solenoid Valve
Span Cal Solenoid Valve
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Model DT3000 Oxygen Analyzer
Version 1.17
TB1 Layout on back of Control
3.3
PNEUMATIC CONNECTIONS
The following gases are needed to accurately operate the Model DT3000.
1. Zero Gas with cylinder regulator capable of being set to
approximately 2-5 psig. Consumption will be approximately about 5.0
SCFH. This gas is connected to the Cal Port of the insitu probe using
1/4” tubing. The zero point O2 concentration should be approximately
1 to 2% O2.
2. Span Gas with cylinder regulator capable of being set to
approximately 2-5 psig. Consumption will be approximately about 5.0
SCFH. This gas is connected to the Cal Port of the insitu probe using
1/4” tubing. The zero point O2 concentration should be approximately
8.0% to 14.0% O2.
3. Since the sensor operates with respect to a reference air, there may
be occasions where the ambient air on the atmospheric side of the cell
needs supplemental air. Connect this via a regulator capable of being
set to 1 psig. Consumption will be approximately 1.0 CFH. This is
connected to the insitu probe air reference port.
4. Back purge air should be connected via a Back Purge solenoid.
This requires a line or tee from the exit port of the solenoid into the
Back Purge port of the O2 insitu probe (see drawing DT3000-07).
Connect the back purge air via a regulator capable of being set to 40
psig. Assuming air lines are ¼’ tube, air Pressure of 5/8/10/12 psi will
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Model DT3000 Oxygen Analyzer
Version 1.17
pull a sample of 3/5/5.5/7 SCFH. This is connected to the insitu probe
purge air port.
When the back purge solenoid is activated there is an immediate blast
of pressurized air which flushes or back flushes the O2 insitu sample
probe filter. In order for a pressurized blast of air to hit the probe filter
the connecting lines to the solenoid should be as short as possible to
avoid restriction.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 4
PARAMETERS DEFINITIONS
4.1
INTRODUCTION
This section goes through each of the parameters that are needed by the
Model DT3000 for operation. The discussion here will detail the full features
and limits of these parameters. The order of presentation will be the same
here as the order they appear in the parameter routine.
4.2
BACK PURGE PERIOD
This parameter determines the period of time between back purges of the
sample probe filter. The back purge period is entered here in hours. The
higher the particulate concentration in the flue gas the more often the filter
should be cleaned, and the shorter this time must be. Back purge is inhibited
during a calibration period.
4.3
BACK PURGE DURATION
The duration of the back purge is set in seconds and is the time that the blow
back solenoid is activated and there is back flow across the filter. In practice
it is generally the initial blast of high-pressure gas that dislodges the
particulates in the filter. Therefore this time can be set quite low (ex. 10 sec).
4.4
ROLLING AVERAGE
The Rolling Average is used to set the time frame for the O2 reading rolling
average that is reported to the authorities. The rolling average is the number
displayed on the Run Screen next to Avg.
4.5
INSTANT AVERAGE
The instant average is the block of time that an O2 reading is averaged over.
It is different from a rolling average in that the time frame is discrete and the
value is discarded at the end of the period. This instant average is used
primarily for trim control.
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Model DT3000 Oxygen Analyzer
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4.6
RECORDER RANGE
The recorder range relates to the analog signal available at the recorder
terminals on the rear of the Model DT3000. This analog signal is obtained
from the digital output and is thus a calibrated signal directly proportional to
the instantaneous concentration the Model DT3000 detector is seeing. This
signal is 4-20 mA. The full-scale value for 20mA is set by the Recorder Range
parameter.
4.7
O2 LOW ALARM SETPOINT
A Low O2 concentration alarm is set to provide relay contacts and alarm
messages for a low O2 condition. If the concentration goes below the low set
point value, two things happen.
1. The display shows the statement ‘LOW O2 ALARM’ at the
bottom of the run display.
2. The low concentration alarm terminals on the rear of the
Model DT3000 will have a contact closure between them.
When the concentration rises above the low set point the relay closure
opens and the alarm on the display is removed.
4.8
HIGH ALARM SETPOINT
A High O2 concentration alarm is set to provide relay contacts and alarm
messages for a high O2 condition. If the concentration goes above the high
set point value, two things happen.
1. The display shows the statement ‘HIGH O2 ALARM’ at the
bottom of the run display.
2. The high concentration alarm terminals on the rear of the
Model DT3000 will have a contact closure between them.
When the concentration falls below the high set point the relay closure
opens and the alarm on the display is removed.
The display indication of an alarm condition alerts the operator to
check the alarm status menu.
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Model DT3000 Oxygen Analyzer
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4.9
CAL PURGE TIME
The Cal Purge Time is used in the various methods for calibration. It is set in
seconds in the parameter routine but in practice it counts down in seconds.
This allows sufficient time for the various gases to flush the sample lines and
O2 cell prior to taking any concentration readings.
4.10 SAMPLE & HOLD IN CAL
The sample and hold in cal is used when the DT3000 is being used for trim
control and the calibration cycle could cause a boiler upset. When an auto
calibration cycle is initiated the last O2 reading on the 4-20ma output. This is
held until the calibration cycle is complete.
4.11 AUTO CALIBRATION
This function allows for an automatic calibration of the instrument on a clock
timed basis. This will use relay contacts to open solenoid valves to perform
the calibration
4.12 SET TIME HH:MM
The control contains a real time clock that is set in military time. Various
routines are automatically initiated based on the time of day. It is important
that this time is set accurately.
4.13 COMMS. SETUP
When communicating with a remote device (DCS, PC, PLC, etc.), each O2
analyzer must have a unique ID number between 0 and 255. The actual ID
number assigned can be anywhere in the appropriate range but ID numbers
must never be duplicated.
Following a parameter routine, the Model DT3000 returns to the Main Menu.
The operator must select the next operation from this menu
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Model DT3000 Oxygen Analyzer
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SECTION 5
The following programming is performed through the Keypad and Display on
the front of the control cabinet. This is shown below.
U
T
I
L
I
T
I
E
S
D
E
SCRIPTION
5.1
INTRODUCTION
The Utility portion of the Main Menu provides a number of features to the
operator as explained below. The Utility Menu is accessed from the Main
Menu by pressing 4.
MAIN MENU
1 - RUN
4 - UTILITIES
2 - CALIBRATION
3 - SET PARAMETERS
There are four different portions of the Utilities Menu.
1-Signals
2-Output
3-Digital In
4-O2 Clamp
The following is a description of the Utilities and what they mean:
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Model DT3000 Oxygen Analyzer
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5.2
SIGNALS
Pressing the “1” key displays the Signals screen shown below:
TEMP = 1000.0
CELL = 18.1
This is used for diagnostic purposes. It shows the current Zirconia cell
temperature and the instantaneous O2 value. In the above example
the Zirconia cell temperature is 1000 degrees Fahrenheit, and the O2
level is 18.1.
Press the “CLR” key to return to the Utilities Screen.
5.3
OUTPUTS
Pressing the “2” key displays the Outputs screen shown below:
DAC Output = 0%
This is also a diagnostic tool to check the digital output signal from the
analyzer. The normal signal output is 4 to 20 ma. When 0% is
programmed the output should be 4 ma, when 100% is programmed
the output should be 20 ma, and when 50% is programmed the output
should be 12 ma.
The opening screen has the Output set to 0%. Pressing the “CLR” key
changes the values. The first press will change the value from 0% to
100%, and the second push will change the value from 100% to 50%.
The third push will return you to the Utilities Menu.
Press the “CLR” key to return to the Utilities Screen.
5.4
DIGITAL IN
Pressing the “3” key displays the Digital In screen shown below:
Digitals = 1__4__78
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This screen will show which digital inputs are presently active. The
display may show anywhere from zero to all eight inputs as is
applicable at any point in time.
Press the “CLR” key to return to the Utilities Screen.
5.5
O2 CLAMP
Pressing the “4” key displays the Digital In screen shown below:
O2 Clamp
Clamp = 17.50 pct
As the Oxygen in the air increases when a process comes off line, the
signal from the Zirconia cell decreases. Eventually the electrical noise
level is above the signal level and the readings become unstable.
For that reason we clamp the O2 to a reasonably high level where we
then display 20.95 which is the amount of oxygen is ambient air.
This screen is used to enter this upper level where the readings are no
longer reliable. As a default this number is set to 17.5%.
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Model DT3000 Oxygen Analyzer
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SECTION 6
STARTUP AND OPERATION
6.1
INTRODUCTION
When the Model DT3000 has been set up as described in section 3, it is then
ready for operation. This section describes what the Model DT3000 does and
what is needed from the operator.
6.2
INITIAL STARTUP
Initially it is suggested that the Model DT3000 be operated with the same
parameters that were in the instrument on arrival. Likewise, the same
calibration can be used that the instrument received during test. This will
insure that there is no problem with the hardware. The following procedure is
therefore recommended.
6.3
SET UP PROCEDURE
Start Up
It is suggested that before configuring the instrument for your specific needs
you verify its performance. The test parameters from the factory reside in the
instrument memory; therefore its performance can be verified. The following
procedure will allow you to verify this performance.
1. Turn the power switch to the ON position. The following vanity
screen will display for a few seconds.
Datatest Industries
Model 3000
Oxygen Analyzer
2. The DT3000 will display the RUN SCREEN as shown below. The
bottom line of this screen is reserved for alarm notification, and will be
blank under normal operating conditions.
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Model DT3000 Oxygen Analyzer
Version 1.17
O2 =0.00%
Avg =0.00%
Temp = 0.00F
3. The instrument will proceed with its warm up and stabilization
routines.
4. Connect the calibration gas line to the insitu O2 sample probe. Set
external cylinder gas pressures to 2 psi.
6.4
SETTING PARAMETERS
Pressing “CLR” on the keypad brings up the Main Menu shown below.
MAIN MENU
1 - RUN
4 - UTILITIES
2 - CALIBRATION
3 - SET PARAMETERS
The instrument operating parameters can be set through the Main Menu by
pressing the “3” key.
The display now appears as follows.
Back Purge Period
The bottom line is the active parameter. Additional parameters can be
accessed by pressing the “” key. Each time the “” is pressed the display
will scroll and show a new parameter on the bottom line. Pressing the “” key
will reverse the direction of the scroll and allow access to a parameter you
may have already past. There are ten (10) parameters that can be accessed
and they are:
Back Purge Period
Back Purge Duration
Rolling Average
Instant Average
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Model DT3000 Oxygen Analyzer
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Recorder Range
O2 Low Set point
O2 High Set point
CAL. Purge Time
Sample & Hold in CAL
Auto Calibration
Set Time HH:MM
Comms. Setup
To edit the BACK PURGE PERIOD make sure it is on the bottom line then
press the “ENT” key. The following prompt will be displayed:
Back Purge Period
BPP = 012 min
To edit the Back Purge Period (BPP), press the numeric keys that correspond
with the desired time and press “ENT” key to accept this value. The
programmable range is 0 minutes to 999 minutes.
This is used only for back purging the stack probe filters. Note that it applies
only if back purging is to be under control by the Model DT3000 for back
purging the insitu sample probe.
A parameter can be changed, as many times as needed, to make sure it is
correct. The value retained by the Model DT3000 will be the value present
when “ENT” key is pressed (unless the value was out of the acceptable
range).
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Back Purge Duration:
Back Purge Period
Back Purge Duration
To program the back purge duration press the “ENT” key. The following
prompt will be displayed:
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Model DT3000 Oxygen Analyzer
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Set Back Purge Dur
BPD = 10 seconds
The Back Purge Duration is the time in seconds for the back purge duration
and should be 0 if a back purge is not desired.
To edit the Back Purge Duration (BPD), press the numeric keys that
correspond to the desired time and press “ENT” key to accept this value. The
programmable range is 1 second to 60 seconds.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Rolling Average:
Back Purge Period
Back Purge Duration
Rolling Average
To program the Rolling Average press the “ENT” key. The following prompt
will be displayed.
Rolling Average
AVERAGE = 1 min
The Rolling Average is used to set the rolling average of the O2 reading that is
displayed on the Run Screen next to Avg.
To edit the Rolling Average, press the numeric keys that correspond to the
desired minutes. The programmable range is from 1 minute to 240 minutes.
Press the “ENT” key to accept this value.
The display scrolls up with the bottom line reading Instant Average.
Back Purge Period
Back Purge Duration
Rolling Average
Instant Average
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Model DT3000 Oxygen Analyzer
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The Instant Average is used to set an average over a block of time. After
the first block of time is averaged a second block of time will be averaged.
Past data is discarded for averaging purposes. The Instant Average is
displayed next to the O2 on the Run Screen. Instant Average is used more
for trim control and Rolling Average is used more for reporting
To program the Instant Average press the “ENT” key. The following prompt
will be displayed.
Instant Average
AVERAGE = 5 sec
To edit the Instant Average, press the numeric keys that correspond to the
desired seconds. The programmable range is from 1 second to 60 seconds.
Press the “ENT” key to accept this value.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Recorder Range:
Back Purge Duration
Rolling Average
Instant Average
Recorder Range
The Recorder Range is from zero to 25 percent full scale in one percent
increments of the recorder.
To program the Recorder Range press the “ENT” key. The following prompt
will be displayed:
Set Recorder Range
Range = 25 percent
To edit the Recorder Range, press the numeric keys that correspond to the
desired percent and press the “ENT” key to accept this value.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading O2 Low Setpoint:
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Model DT3000 Oxygen Analyzer
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Rolling Average
Instant Average
Recorder Range
O2 Low Setpoint
The O2 Low Set point is used to set the lower end of the O2 alarm range. If
the O2 falls below the value of the O2 low set point the analyzer will send an
alarm and display an alarm on the bottom line of the Run Screen.
To program the O2 Low Set point, press the “ENT” key. The following prompt
will be displayed.
Set O2 Low Set point
O2 Low = 2.00 pct
To edit the O2 Low Set point, press the numeric keys that correspond to the
desired percent. It is recommended that this alarm be set low enough that it
does not trigger during start up. The programmable range is from .1 percent
to 25 percent. Press the “ENT” key to accept this value.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading O2 High Set point.
Instant Average
Recorder Range
O2 Low Set point
O2 High Set point
The O2 High Set point is used to set the lower end of the O2 alarm range. If
the O2 exceeds the value of the O2 High set point the analyzer will send an
alarm and display an alarm on the bottom line of the Run Screen.
To program the O2 High Set point, press the “ENT” key. The following prompt
will be displayed.
Set O2 High Set point
O2 High = 15.00 pct
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Model DT3000 Oxygen Analyzer
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To edit the O2 High Set point, press the numeric keys that correspond to the
desired percent. The programmable range is from .1 percent to 25 percent.
Press the “ENT” key to accept this value.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Cal Purge Time:
Recorder Range
O2 Low Set point
O2 High Set point
Cal Purge Time
Cal Purge Time is used when in calibration to allow sufficient time for the
calibration gases to flush the sample lines and the detector prior to taking a
reading. It is entered in seconds. This parameter should be 00 if CAL
PERIOD = 00.
To edit Cal Purge Time press the “ENT” key. The following prompt will be
displayed.
Set CAL Purge Time
CPT = 60 sec.
To edit the CAL Purge Time, press the numeric keys that correspond to the
desired seconds and press the “ENT” key to accept this value. The
programmable range is from 1 second to 600 seconds.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Sample & Hold in CAL.
O2 Low Set point
O2 High Set point
Cal Purge Time
Sample & Hold in CAL
The Sample & Hold in CAL is used to ensure that if you are using the unit for
TRIM CONTROL, the analog outputs will lock at the last measured O2 values
prior to the cal procedure being invoked. This will prevent the boiler control
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Model DT3000 Oxygen Analyzer
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instrument from being upset by the swings in O2 from Zero to Span as the
instrument executes its cal cycle.
To program the Sample & Hold in CAL, press the “ENT” key. The following
prompt will be displayed.
Sample & Hold in CAL
Sample & Hold = 0
To edit the Sample & Hold in CAL, press the numeric keys that correspond to
the desired percent. The Sample & Hold can be programmed to be either
enabled or disabled. Press “0” to disable this function, or press “1” to enable
this function. Press the “ENT” key to accept the value chosen.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Auto Calibration.
O2 High Set point
Cal Purge Time
Sample & Hold in CAL
Auto Calibration
Auto calibration, when enabled, permits the analyzer to automatically perform
O2/CO Zero calibration and O2/CO Span calibration at programmable time
intervals. A start time (Auto CAL. Hour), and a repetition period (Auto CAL>
Period) for this auto calibration are field programmable.
To edit Auto Calibration press the “ENT” key. The following prompt will be
displayed.
Auto CAL. Period
Period = 24 hours
The auto cal period is the time period (in hours) between auto calibrations.
The reference start time for the first calibration is set below in the Auto CAL.
Hour.
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Model DT3000 Oxygen Analyzer
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To edit the Auto CAL. Period press the numeric keys that correspond to the
desired hours. The programmable range is from 1 hour to 24 hours.
Press the “ENT” key to accept this value and move to the Auto CAL. Hour
setup screen shown below.
Auto CAL. Hour
Hour = 0
The Auto CAL. Hour is the hour of the day (in military time) that the Auto
CAL> Period is referenced from. As an example, if the Auto CAL. Hour is
programmed to 12, and the Auto CAL. Period is programmed to 8, the auto
calibrate routine will start at 12:00 Noon, and repeat at 8:00 pm, 4:00 am, and
12:00 Noon again. This cycle will repeat as long as the times are not
changed and the analyzer is not turned off. If the analyzer is turned off, the
auto calibrate routine will begin again when the analyzer is turned on and
repeat at the Auto CAL. Period time interval. When the Auto CAL. Hour is
reached the system will synchronize to this time and the original cycle will
again become active.
To edit the Auto CAL. Hour press the numeric keys that correspond to the
desired hour. The programmable range is from 1 hour to 23 hours. Press the
“ENT” key to accept this value and move to the Auto CAL. Enable setup
screen shown below.
Auto CAL. Enable
Enable = 0
To edit the Auto CAL. Enable either press the “1” numeric key to enable the
auto calibrate routine, or the “0” numeric key to disable the auto calibrate
routine. Press the “ENT” key to accept this value and return to the parameter
screen.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Set Time HH:MM:
Cal Purge Time
Sample & Hold in CAL
Auto Calibration
Set Time HH:MM
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Model DT3000 Oxygen Analyzer
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To program the Set Time press the “ENT” key. The following prompt will be
displayed:
ENT to change
CLR to Return
Time = 09:34
Pressing the “ENT” key will bring up the display below. Pressing the “CLR”
key will return you to the Parameter screen.
Set Time HH:MM
Time =
To edit the Set Time, press the numeric keys that correspond to the desired
hours and minutes. The time must be entered in military time. Press the
“ENT” key to accept this value. DO NOT PUSH THE ENTER KEY IF THERE
IS NO TIME ENTERED.
Advance to the next parameter by pressing the “” key.
The display scrolls up with the bottom line reading Comms. Setup.
Sample & Hold in CAL
Auto Calibration
Set Time HH:MM
Comms. Setup
To edit Comms. Setup, press the “ENT” key. The following prompt will be
displayed.
MODBUS I.D.
I.D. = 0
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Model DT3000 Oxygen Analyzer
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When communicating with a remote device (DCS, PC, PLC, etc.), each O2
analyzer must have a unique ID number between 0 and 255.
To edit the Modbus ID, press the numeric keys that correspond to the desired
number and press the “ENT” key to accept this value.
The following screen will now be displayed:
MODBUS Port Parity
0=Even, 1=Odd
Parity = 0
If the system is communication with a remote device, the remote device and
the analyzer must both be communicating with the same parity. Press either
the “0” or “1” key depending on the parity desired, and then the “ENT” key.
The following screen will be displayed.
MODBUS Baud Rate
4800, 9600, 19200
Baud = 09600
If the system is communication with a remote device, the remote device and
the analyzer must both be communicating with the Baud Rate. Press the
numeric keys that correspond to the desired baud rate, and then the “ENT”
key.
Pressing the clear “CLR” key from any screen (some screens require
the “CLR” key to be pressed more than once) will bring up the Main
Menu screen. The Main Menu will now be displayed on the screen.
MAIN MENU
1 - RUN
4 - UTILITIES
2 - CALIBRATION
3 - SET PARAMETERS
The selection of ‘1’ from the Main Menu places the Model DT3000 in
automatic run mode. The Model DT3000 will begin its normal operation of
measuring O2 levels in air samples following the guidelines established in the
parameter routine.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 7
CALIBRATION
7.1
INTRODUCTION
A Zirconia sensor based oxygen analyzer needs initial and periodic
calibration, using known test gases, for several reasons.
Initial calibration is required to set the linearization curve for the
installed conditions.
Periodic calibration to reset linearization due to electronic component
aging, sensor aging, and changes in the flue gas conditions.
For EPA reporting a calibration check is required once every 24 hours.
For trim control a calibration is typically required once every three months, or
whenever a new sensor is installed.
7.2
CALIBRATION
For calibration, connect the Cal gases as described earlier in this manual.
The Zero or Span calibration gases are to be introduced to the calibration port
of the Model DT3000 insitu probe at positive pressure. Calibration gas flow
rates should be adjusted to around 5 SCFH.
To begin a Calibration cycle, start at the Main Menu.
MAIN MENU
1 - RUN
4 - UTILITIES
2 - CALIBRATION
3 - SET PARAMETERS
Press the “2” key to enter the Calibration screen.
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Model DT3000 Oxygen Analyzer
Version 1.17
1-Cal Zero Adjust
2-Cal Span Adjust
3-Zero Check
4-Span Check
From here press the “1” key for Cal Zero Adjust and the “2” key for Span Cal
Adjust.
To call for a Zero calibration, select 1 on the Calibration Menu. The display
will then appear as follows:
** Calibrate **
Manual Zero
Purge Delay = 120
O2 = 2.2 [ 2.0]
The second line states that the calibration is a Zero Cal. The third line shows
that the purge time has 120 seconds left. This time starts counting down, in
seconds, from the Cal Purge Time that was set in the Parameters.
The final line is the O2 level, in percent, based on the previous calibration.
The number in brackets is the value of the O2 in the Zero calibration gas that
is entered in the Calibration Screen under Zero Check. After the Cal Purge
Time has elapsed, the Model DT3000 will wait an additional 5 seconds to
allow sampling of the calibration gas. At the finish of the Cal Purge Time the
display reverts back to the Calibration Menu.
To complete the calibration procedure, the Span Adjust must be accessed
through the Calibration Menu by selecting 2. At this point the Span solenoid
opens admitting the Span gas to the Model DT3000. The span flow should
be adjusted as the zero flow was previously. The display will change to:
** Calibrate **
Manual Span
Purge Delay = 120
O2 = 12.05 [15.00]
The second line states that the span calibration was called for. The third line
shows that the purge time has 120 seconds left. This time starts counting
down, in seconds, from the Cal Purge Time that was set in the Parameters
(See Section 6.4).
The final line is the O2 level, in percent, based on the previous calibration.
The number in brackets is the value of the O2 in the Span calibration gas that
is entered in the Calibration Screen under Span Check. After the Cal Purge
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Model DT3000 Oxygen Analyzer
Version 1.17
Time has elapsed, the Model DT3000 will wait an additional 5 seconds to
allow sampling of the calibration gas. At the finish of the Cal Purge Time the
display reverts back to the Calibration Menu
If the analyzer fails calibration for any reason it reverts back to the precalibrate conditions.
7.5
ZERO AND SPAN CHECK
Two other features available from the Calibration Menu are the Zero and
Span Check. Pressing 3 from the Calibration Menu brings up the Zero Cal
Gas Set screen.
Set O2 Zero CAL Gas
ZERO = 2.00 pct
Press the numeric keys that correspond to the oxygen concentration found on
the Zero calibration gas bottle/tank. This number represents the analyzer’s
Zero value calibration.
Pressing 4 from the Calibration Menu brings up the Span Cal Gas Set screen.
Set O2 Span CAL Gas
SPAN = 15.00 pct
Press the numeric keys that correspond to the oxygen concentration found on
the Span calibration gas bottle/tank. This number represents the analyzer’s
Span value calibration.
7.7
ABORT TECHNIQUES FROM CALIBRATION
In calibration there is a purge delay time before the calibration commences.
Pressing the clear key within this delay time will abort the calibration.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 8
DIAGNOSTIC DISCUSSION
8.1
INTRODUCTION
During operation up of the Model DT3000 various diagnostic messages may
appear in the display. Each of these messages is discussed below:
8.2
CALIBRATION FAULT
If during the calibration period the analyzer detects an O2 value less than 6
points below the calibration gas value, or 6 points above the calibration gas
value. A “Calibration Fault” alarm message will appear on the bottom line of
the Run screen to indicate the analyzer is out of calibration.
The on board alarm contact will close during this alarm condition providing a
means for remote alarm indication.
8.3
HIGH SENSOR TEMP
If the temperature of the Zirconia sensor exceeds the analyzer’s preset upper
limit a “High Sensor Temp” alarm message will appear on the bottom line of
the Run screen to indicate the analyzer is out of calibration.
The on board alarm contact will close during this alarm condition providing a
means for remote alarm indication.
In addition to the above the analyzer will attempt to reduce the temperature of
the Zirconia cell. If the temperature returns to normal the alarm will clear.
8.4
LOW SENSOR TEMP
If the temperature of the Zirconia sensor falls below the analyzer’s preset
lower limit a “Low Sensor Temp” alarm message will appear on the bottom
line of the Run screen to indicate the analyzer is out of calibration.
The on board alarm contact will close during this alarm condition providing a
means for remote alarm indication.
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Model DT3000 Oxygen Analyzer
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In addition to the above the analyzer will attempt to increase the temperature
of the Zirconia cell. If the temperature returns to normal the alarm will clear.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 9
INSTRUMENT DESCRIPTION
9.1
INTRODUCTION
The Model DT3000 microprocessor controller contains features necessary to
maintain the oxygen sensor at its operating temperature, and to display
values corresponding to percentage of oxygen in the flue gas.
The Model DT3000 comes with a 4-line, 80-character LCD display and a 16key membrane keypad. User interface is through the keypad and LCD
display, which displays measurements, system status messages, and alarms.
Sensor calibration is also initiated through the keypad.
9.2
O2 CELL ANALOG CIRCUIT
The Zirconia cell provides a current output that is conditioned and amplified to
provide a voltage output to a microprocessor.
The signal from the Zirconia cell is in the form of a very low ion current.
9.3
O2 CELL THERMOCOUPLE CIRCUIT
A type K thermocouple is inserted into the center of the Zirconia cell for
monitoring cell temperature. This thermocouple provides a voltage that is
proportional to the temperature of the Zirconia cell. A typical cell temperature
is 1000°F to provide a thermocouple output of 22.250 mV. The resistance of
the thermocouple is approximately 2 ohms at 70°F when disconnected.
The O2 cell thermocouple voltage signal is conditioned and amplified to
provide a voltage output to a microprocessor
9.4
RELAY OUTPUTS
The Model DT3000 provides relay outputs (SPST) for low and high set point
alarms, system fault and back purge. These relay outputs are provided on
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Model DT3000 Oxygen Analyzer
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TB1 located on the back panel of the enclosure. All relay contacts are
Normally Open (N.O.) and will provide a contact closure when energized.
9.5
INPUTS
The Model DT3000 has digital inputs for initiating a remote zero and span
procedure. 120VAC applied to the appropriate input will induce the
appropriate procedure.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 10
OXYGEN SENSOR
10.1
OXYGEN SENSOR - GENERAL
The oxygen sensor consists of a Zirconia oxide sensor, which is threaded into
the sample cell. The sensor consists of two component groups, sensor
exterior (air reference) and inner sensor (sample). It creates an electrical
signal when oxygen level on the sample side of the cell is not equal to oxygen
levels on the reference airside. This signal is proportional to the difference in
oxygen levels.
10.2
ZIRCONIA SENSOR ASSEMBLY
The O2 cell comprises of a Zirconia oxide sensor and a type-K thermocouple
inserted into the center of the Zirconia sensor. A heater element surrounds
the Zirconia sensor and maintains the Zirconia cell at about 1000°F. Air
reference holes are provided at the top of the Zirconia sensor.
The complete Zirconia cell with thermocouple, threads into the sample cell for
direct measurement of flue gas (insitu-wet), or conditioned sample gas
(extractive-dry).
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Model DT3000 Oxygen Analyzer
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SECTION 11
TROUBLE SHOOTING
11.1
OVERVIEW
The system troubleshooting section is divided into two parts that describe
how to identify and isolate oxygen analyzer faults. The first part describes
sensor faults and the second describes electronic faults. The alarms and
messages caused by either may overlap.
11.2
SPECIAL TROUBLESHOOTING NOTES
a. Grounding: It is essential that adequate grounding precautions are taken
when system is being installed. Thoroughly check all grounding connections
before and after faultfinding.
b. Loose Integrated Circuits: The electronics uses a microprocessor and
supporting integrated circuits. Should the electronics receive rough handling
during installation, or is installed in a location that is subject to severe
vibration, an integrated circuit (IC) could work loose. Make sure all IC’s are
fully seated before system troubleshooting begins.
11.3
SENSOR TROUBLESHOOTING
a. Sensor Faults: Listed below are three symptoms of sensor failure.
1. The system does not respond to changes in oxygen
concentration.
2. The system responds to changes in oxygen concentration,
but does not give correct indication.
3. The system does not give an acceptable indication of the
value of the test gas being applied during calibration.
b. Fault Finding: The following Table is a guide for finding faults of
the above symptoms.
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Model DT3000 Oxygen Analyzer
Version 1.17
MALFUNCTION
POSSIBLE
FAILURE
CHECK
Heater is cold and
T/C mV output is
less than set
point.
Thermocouple
Thermocouple
continuity Check
electrical
connections /
Thermocouple
polarity
Replace T/C or replace
Zirconia sensor. Correct
wiring
Fuse Blown
Check Fuse
Replace fuse.
Solid state relay
to heater
Failure of
electronics or S.S
Relay
Replace mother board or
solid state relay
No cell mV at
sensor.
Cell mV input to
electronics and
mV at sensor
head.
Replace Zirconia sensor.
Sensor mV
normal but no
input to
electronics.
Cable connection. Check cable connection.
Cell mV normal
at sensor head
and input to
electronics
Failure of
electronics
Heater is hot and
T/C mV output is
at set point.
44
REMEDY
Replace oxygen PCB and
return faulty board to
Datatest.
Model DT3000 Oxygen Analyzer
Version 1.17
MALFUNCTION
POSSIBLE
FAILURE
CHECK
System responds
to oxygen
concentration
changes but does
not give correct
reading.
Calibration error.
System
calibration.
Recalibrate system.
Vacuum leak. Air
getting in sample
line
.
Extractive
system.
Stop air leak.
Leaky zero, span
or back purge
solenoid
Check back
purge and cal
solenoids.
Stop solenoid leak.
Failure of
electronics.
Cell mV input to
electronics.
Replace oxygen PCB and
return faulty board to
Datatest.
Blocked sample
line.
Test sample inlet
port.
Clean port.
Verify calibration
gas
concentrations.
Replace calibration gas
container.
System does not
give accurate
indication of
applied test gas.
11.4
REMEDY
Check sample
line and fittings.
ELECTRONICS TROUBLESHOOTING
The Model DT3000 has on-board diagnostic features, which aid faultfinding.
Normally the user will not need to use electronic testing equipment in fault
diagnostic. Almost all reasons for system malfunction are displayed by either
an alarm or a fault message on the liquid crystal display.
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Model DT3000 Oxygen Analyzer
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11.5
ALARM MESSAGES
The Model DT3000 has various diagnostic alarm features, which may appear
in the display.
Low Sensor Temp
High Sensor Temp
Backpurge
Thermocouple Fault
Calibration Fault
Remote Calibration
Each of these alarm messages is discussed in this manual.
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Model DT3000 Oxygen Analyzer
Version 1.17
SECTION 12
SERVICE AND NORMAL MAINTENANCE
12.1
OVERVIEW
This section describes routine maintenance of the Model DT3000 Oxygen
Analyzer. Spare parts referred to are available from Datatest. Observe
warning and caution labels.
12.2
PRELIMINARY CHECKS
The following preliminary checks will help isolate problems in the analyzer.
Run these checks before beginning any repair work. Check parameter and
displays according to instructions in Section 4, System Startup.
WARNING: Wear heat resistance gloves when handling hot sensor and
analyzer parts. The parts may be hot enough to cause severe burns.
a. Check Display for Alarms: Go through normal power up
procedure. Allow enough time for sensor to reach proper temperature.
Check display for alarms. If there are alarms, troubleshoot.
b. Run Calibration Check: Run calibration check procedure
according to section 7. If calibration is successful, no problem exists.
If calibration fails, shut off power and make sure that all wires and gas
lines are properly connected to analyzer. If everything checks out
properly, proceed to step c.
c. Check Thermocouple Output: Turn power on. Check
thermocouple mV output. It should be at the mV set point (22.25 mV
+/- 0.2 mV). If output is incorrect, check heater fuse. If fuse is good,
check heater and thermocouple resistance as follows.
1. Measure heater resistance. Measure resistance of heater
element at heater terminal on O2 Sensor Assembly. The
resistance should be less than 2 ohms. If heater element is
open circuit, replace sensor heater element in sample cell.
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Model DT3000 Oxygen Analyzer
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2. Measure thermocouple resistance. Measure the
thermocouple resistance on top of the Zirconia sensor located
on the sample cell or O2 insitu head. The resistance of the
thermocouple should be approximately 2 ohms at 70°F.
12.3
SENSOR CALIBRATION:
The Datatest Model DT3000 Oxygen Analyzer should be calibrated when
installed. Under normal operation, sensor will not require frequent calibration.
When calibration is required, follow the procedures in section 7.
12.4
SENSOR REMOVAL AND INSTALLATION:
SENSOR REMOVAL: This paragraph covers the oxygen sensor removal
from the sample cell or insitu head. Use the following procedure to remove
sensor from the Model DT3000 for repair or replacement.
1. Disconnect and turn off AC power to the O2 control unit. Shut off all
calibration gases. Do not attempt to work on sensor assembly until it
as cooled to a comfortable working temperature.
2. Disconnect sample gas tubing, reference gas tubing, back purge
and exhaust tubing to casting of O2 sensor assembly.
3. For rack mount units, remove screws from front panel securing
sensor assembly to panel. Remove sensor assembly. For Insitu units,
remove O2 probe assembly cover plate from air reference cell to
expose Zirconia sensor.
4. Disconnect thermocouple wire extension, cell wires and heater
wires from sensor ceramic connectors.
5. Using a 7/8” wrench, remove Zirconia sensor from its threaded port.
SENSOR INSTALLATION: Use the following procedure to install Zirconia
sensor into the Model DT3000.
1. Using a 7/8” wrench, thread Zirconia sensor into casting of O2 cell.
2. Connect type K thermocouple extension wires, cell wires and heater
wires to ceramic connectors as follows:
TB1/6
TB1/7
THERMOCOUPLE (+) YEL
THERMOCOUPLE (-) RED
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Model DT3000 Oxygen Analyzer
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TB1/4
TB1/5
CELL SIGNAL (+)
CELL SIGNAL (-)
TB1/25
TB1/26
Heater – pulsed 10 VAC
Heater – pulsed 10 VAC
3. For extractive units, secure sensor assembly to front panel of
control unit, or remote location as applicable. For Insitu units, replace
O2 probe assembly cover plate over the casting on the Insitu probe.
4. Connect sample gas tubing, reference gas tubing, back purge, and
exhaust tubing to casting of O2 sensor assembly.
5. Connect sensor thermocouple extension wire, cell signal wires, and
heater wires to control unit as specified in 2 above.
12.5
HEATER ELEMENT REPLACEMENT
The heater element surrounds the threaded tip of the Zirconia sensor.
Should this element fail for any reason, the Sensor housing assembly
should be sent to Datatest for repair.
12.7
SPARE PARTS
Spare Parts List
---------------------------------------------------------------------------------------PART NUMBER
DESCRIPTION
QUANTITY
---------------------------------------------------------------------------------------DK5020
Zirconia Sensor Unit
1
Including thermocouple assembly
300-TRH
Heater Transformer 8-10
1
DK5029
Solid State Relay (SSR), 10 Amp
1
3AG
BLF3
Fuse, 2 amp
Fuse, 3 amp
1
DT3000-PCB
Main Controller Card
1
---------------------------------------------------------------------------------------
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Model DT3000 Oxygen Analyzer
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13
WARRANTY
Datatest guarantees this system for a period of eighteen (18) months from
date of installation to be free from defects in material and workmanship.
Our obligation under this guarantee is limited to repairing or replacing any
instrument or part thereof which shall, within the above specified time, be
returned to us with transportation charges prepaid, and prove after our
examination to be thus defective. Should the product be found not to be
defective a diagnostic and recalibration charge will apply.
The gas sensor element is excluded from this warranty.
In the event that the customer requires a Datatest field service technician or
engineer on site, the customer will be billed for this service at our standard
rate. This applies whether the equipment is in or out of warranty. This daily
rate is based on the man-days spent ‘on site’, plus travel time. Expenses for
travel and living are billed at cost.
Datatest personnel will not accept instruments returned under this warranty,
to the Datatest plant, without prior authorization.
The user must prepay Freight for Returned Equipment. Datatest will
assume the cost of shipping the unit back to the user by common carrier. If
the user wishes it returned by other means, the user will be billed for the
additional charges.
We reserve the right to discontinue instruments without notice, and to make
modifications in design at any time without incurring any obligation to make
such modifications to instruments previous sold.
13.1
RETURNING EQUIPMENT TO THE FACTORY
If factory repair of equipment is required, proceed as follows.
a. Secure a return authorization number from a Datatest Sales Office before
returning the equipment. Equipment must be returned with complete
identification in accordance with Datatest instructions or it will not be
accepted.
In no event will Datatest be responsible for equipment without proper
authorization and identification.
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Model DT3000 Oxygen Analyzer
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b. Carefully pack the equipment in a sturdy box with sufficient shock
absorbing material to insure that no additional damage will occur during
shipping.
c. In a cover letter, describe completely:
1. The symptoms that made you think the equipment is faulty.
2. The environment in which the equipment has been operating (i.e.
temp, corrosive gasses, moisture, etc.).
3. Name of your company and plant name where equipment was
removed.
4. Plant contact and phone number.
5. Whether warranty service or non-warranty service is expected.
6. Complete shipping instructions for return of equipment.
d. Enclose the cover letter and purchase order and ship the equipment
according to instructions provided in Datatest Return Authorization, prepaid
to:
DATATEST Inc.
300 Valley Road
Hillsborough, NJ 08844
TEL: (908) 369-1590
FAX: (908) 369-1594
If warranty service is requested, the unit will be carefully inspected and tested
at the factory. If failure was due to conditions listed in the standard Datatest
warranty, the unit will be repaired or replaced at Datatest option, and an
operating unit will be returned to the customer in accordance with shipping
instructions furnished in the cover letter.
For equipment no longer under warranty, the equipment will be repaired at the
factory and returned as directed by the purchase order and shipping instructions.
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Model DT3000 Oxygen Analyzer
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14 Modbus Registers
Operating information and status of the DT3000 can be sent to a remote
computer/DCS/PLC via Modbus RTU protocol. The following are the register
descriptions.
Diagnostic registers
40001
Message Counter. This register increments for every valid
received message.
40002
Read register (03) message counter. This register is
incremented for every received message that is a read holding
register command.
40003
Invalid CRC message counter. This register is incremented for
messages that have been received with a bad CRC.
40004
Exception response message counter. This register is
incremented when the instrument transmits a MODBUS
exception response.
40005
Reserved
40006
Last exception code. This register holds the last exception code
that was transmitted.
40007-9
Reserved
40010-17
Last exception response message. Eight registers holding the
character data of the last exception response that was
transmitted.
System Registers
40021
Back purge timer. The incrementing back purge timer value in
minutes.
40022
Back purge flag. Value equals 1 when the instrument is
performing a back purge otherwise it is zero.
40023
System Status.
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Model DT3000 Oxygen Analyzer
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40031
O2 instantaneous reading. The register is an integer value. The
oxygen reading is multiplied by 100 to give an integer value in
increments of hundredths. This is the fastest changing O2 value. The
value is in the range of 0 to 2500.
40032
O2 instantaneous average reading. The register is an integer value of
the “instantaneous” rolling seconds average. The O2 reading is
multiplied by 100 to give an integer value in increments of hundredths.
The value is in the range of 0 to 2500.
40033
O2 average reading. The register is an integer value of the minute
rolling average. This O2 reading is multiplied by 100 to give an
integer value in increments of hundredths. This is the slowest
changing O2 value. The value is in the range of 0 to 2500.
40034-35
O2 instantaneous reading. These registers hold a floating-point value.
This is the fastest changing O2 value.
40036-37
O2 instantaneous average reading. These registers hold a floatingpoint value of the “instantaneous” rolling seconds average.
40038-39
O2 average reading. These registers hold a floating-point value of the
“averaged” minute rolling average. This is the slowest changing O2
value
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Model DT3000 Oxygen Analyzer
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Appendix I – Drawings for Insitu Unit, Panel Mount
Control Unit
The reduced size drawings on the following pages are provided as typical for the
specific design stated above. Larger drawings and/or electronic drawings are
provided for the actual design purchased.
DT3000-05, Oxygen Probe
DT3000-06, Panel Mount Overview
DT3000-07, Oxygen Probe Overview
06-3881-XXXX, Panel Mount Wiring Diagram
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Appendix II – Drawings for Insitu Unit, NEMA 4
Control Unit
The reduced size drawings on the following pages are provided as typical for the
specific design stated above. Larger drawings and/or electronic drawings are
provided for the actual design purchased.
07-3766 Rev. 1 Control Cabinet Overview
07-3763 Rev. 3 Overall Wiring
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Appendix III – Drawings for Extractive Rack Mount
Control Unit
The reduced size drawings on the following pages are provided as typical for the
specific design stated above. Larger drawings and/or electronic drawings are
provided for the actual design purchased.
B02-3712 Sample Probe
DT3000-04 Rev. 1 Rack Mount Overview & Connections
06-3879 Wiring Diagram
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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Appendix IV – Drawings for Self Contained Control
Unit
The reduced size drawings on the following pages are provided as typical for the
specific design stated above. Larger drawings and/or electronic drawings are
provided for the actual design purchased.
07-3803 Rev. 1 Analyzer Overview
06-3800 Wiring Diagram
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Model DT3000 Oxygen Analyzer
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Model DT3000 Oxygen Analyzer
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68
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