AII GPR-2500 User manual

2855 Metropolitan Place, Pomona, CA 91767 USA ♦Tel: [phone], Fax: [phone], www.aii1.com, e-mail: [email protected] Rev 10/15
Technical Specifications *
Accuracy: < 2% of FS range under constant conditions
Analysis: 0-1%, 0-5%, 0-10%, 0-25% FS ranges; auto-ranging or
fixed single range
Application: Oxygen analysis in inert, hydrocarbon, helium, hydrogen,
mixed and acid (CO2) gas streams
Approvals: Certified for use in hazardous areas - see lower right
Area Classification: Class I, Division 1, Group C, D hazardous areas with
external intrinsic safety barrier
Calibration: Max interval—3 months. Air calibrate with clean source
of certified span gas, compressed, or ambient (20.9%
O2) air on 0-25% range.
Compensation: Temperature
Connections: 1/8" compression tube fittings
Controls: Water resistant keypad; menu driven range selection,
calibration and system functions
Display: Graphical LCD 2.75” x 1.375”; resolution 0.001%;
displays real time ambient temperature and pressure
Enclosure: Painted aluminum 4 x 9 x 3", 8 lbs.
Flow Sensitivity: None between 0.5-5 SCFH, 1-2 SCFH recommended
Linearity: ±1% of full scale
Pressure: Inlet - regulate to 5-30 psig to deliver 1-2 SCFH flow;
vent - atmospheric
Power: 18-24 VDC
Response Time: 90% of final reading in 13 seconds
Sample System: None
Sensitivity: < 0.5% of FS range
Sensor Model: GPR-11-32-RTS for non-acid (CO2) gas streams;
XLT-11-24-RTS for gases containing > 0.5% CO2
Sensor Life: GPR-11-32-RTS 32 months in air at 25ºC and 1 atm
XLT-11-24-RTS 24 months in air at 25ºC and 1 atm
Signal Output: 4-20mA non-isolated
Operating Range: 5ºC to 45ºC (GPR sensor), -10ºto 45ºC (XLT sensor)
Warranty: 12 months analyzer; 12 months sensor
Wetted Parts: Stainless steel
Optional Equipment
Sample conditioning system - Contact factory.
* Subject to change without notice
GPR-2500 ATEX
Oxygen Transmitter
Intrinsic Safety Barrier MTL7706+ or Equivalent
2 Wire Loop Powered O2 Transmitter
Advanced Galvanic Sensor Technology with
Optional Sample Systems
ATEX Certified for Hazardous Areas
0080
ATEX Certified - Directive 94/9/EC
Examination Cert: INERIS 08ATEX0036
II 2 G
Ex ia IIB T4
Tamb -20⁰C to +50⁰C
ISO 9001:2008 Certified
INTERTEK Certificate No. 485

Advanced Instruments Inc.
GPR-2500
% Oxygen Transmitter
Owner's Manual
Revised July 2013
Revised April 2014
2855 Metropolitan Place, Pomona, California 91767 USA ♦Tel: [phone], Fax: [phone], e-mail:
[e-mail]

Advanced Instruments Inc.
Table of Contents
Introduction
1
Quality Control Certification
2
Safety
3
Features & Specifications
4
Operation
5
Maintenance
6
Spare Parts
7
Troubleshooting
8
Warranty
9
Material Safety Data Sheets
10
Drawings
A/R
Explosion Proofing Electrical Connections
Appendix
A
Correlating readings – LCD display to 4-20mA signal
output
Appendix
B
H2S Scrubber, Sample System, Media MSDS
Appendix
F
Maintenance H2S Scrubber & Coalescing Filter
Appendix
G
The appendices referenced above are an integral part of the documentation, installation and maintenance of this
analyzer to comply with all applicable directives. It is important that users review these documents before proceeding.
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1. Introduction
Your new oxygen transmitter incorporates an advanced electrochemical sensor specific to oxygen along with state-of-
the-art digital electronics designed to give you years of reliable precise oxygen measurements in a variety of industrial
oxygen applications. More importantly, it has been constructed as intrinsically safe in accordance with ATEX Directives
94/9/CE for use in hazardous areas in zone 1 Group C and D.
Analytical Industries, Inc.
dba Advanced Instruments Inc.
2855 Metropolitan Place, Pomona, CA 91767 USA
GPR-1500/2500
0080
Serial No.:
Year of Manufacture:
INERIS 08ATEX0036
II 2 G
Ex ia IIB T4 Gb
Tamb -20⁰C to +50⁰C
WARNING: POTENTIAL ELECTROSTATIC CHARGING HAZARD – SEE INSTRUCTIONS
The design also meets NEC intrinsic safety standards for use in Class 1, Division 1, Group C, D hazardous areas.
Please refer to Appendix A for information on making electrical connections that maintain the desired level of
protection.
To obtain maximum performance from your new oxygen transmitter, please read and follow the guidelines provided in
this Owner’s Manual.
Every effort has been made to select the most reliable state of the art materials and components, to design the
transmitter for superior performance and minimal cost of ownership. This transmitter was tested thoroughly by the
manufacturer prior to shipment for best performance.
However, modern electronic devices do require service from time to time. The warranty included herein plus a staff of
trained professional technicians to quickly service your transmitter is your assurance that we stand behind every
transmitter sold.
The serial number of this transmitter may be found on the inside the transmitter enclosure. You should note the serial
number in the space provided and retains this Owner’s Manual as a permanent record of your purchase, for future
reference and for warranty considerations.
Serial Number: _______________________
Advanced Instruments Inc. appreciates your business and pledges to make every effort to maintain the highest
possible quality standards with respect to product design, manufacturing and service.
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3. General Safety & Installation
This section summarizes the essential precautions applicable to the GPR-1500/2500 Oxygen Transmitter. Additional
precautions specific to individual transmitter are contained in the following sections of this manual. To operate the
transmitter safely and obtain maximum performance follow the basic guidelines outlined in this Owner’s Manual.
Caution: This symbol is used throughout the Owner’s Manual to Caution and alert the user to
recommended safety and/or operating guidelines.
Warning: This symbol is used throughout the Owner’s Manual to Warn and alert the user of the presence
of electrostatic discharge.
Danger: This symbol is used throughout the Owner’s Manual to identify sources of immediate Danger
such as the presence of hazardous voltages.
Read Instructions: Before operating the transmitter read the instructions.
Retain Instructions: The safety precautions and operating instructions found in the Owner’s Manual should be
retained for future reference.
Heed Warnings: Follow all warnings on the transmitter, accessories (if any) and in this Owner’s Manual.
Follow Instructions: Observe all precautions and operating instructions. Failure to do so may result in personal injury
or damage to the transmitter.
Analyzer label
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Maintenance
Serviceability: Except for replacing the oxygen sensor, there are no parts inside the transmitter for the operator to
service.
Only trained personnel with the authorization of their supervisor should conduct maintenance.
Oxygen Sensor: DO NOT open the sensor. The sensor contains a corrosive liquid electrolyte that could be harmful if
touched or ingested, refer to the Material Safety Data Sheet contained in the Owner’s Manual appendix. Avoid contact
with any liquid or crystal type powder in or around the sensor or sensor housing, as either could be a form of
electrolyte. Leaking sensors should be disposed of in accordance with local regulations.
Troubleshooting: Consult the guidelines in Section 8 for advice on the common operating errors before concluding
that your transmitter is faulty. Do not attempt to service the transmitter beyond those means described in this Owner’s
Manual.
Do not attempt to make repairs by yourself as this will void the warranty as per Section 10 and may result in electrical
shock, injury or damage. All other servicing should be referred to qualified service personnel.
Cleaning: The transmitter should be cleaned only as recommended by the manufacturer. Wipe off dust and dirt from
the outside of the unit with a soft damp cloth then dry immediately. Do not use solvents or chemicals.
Nonuse Periods: If the transmitter is equipped with a POWER switch advance the switch to the OFF position and
disconnect the power when the transmitter is left unused for a long period of time.
Installation
This analyzer has been constructed in compliance with
EN 60079-0 : 2007
EN 60079-11 : 2012
It must be installed in accordance with
EN 60079-14
Gas Sample Stream: Ensure the gas stream composition of the application is consistent with the specifications and if
in doubt, review the application and consult the factory before initiating the installation. Note: In natural gas
applications such as extraction and transmission, a low voltage current is applied to the pipeline itself to inhibit
corrosion of the pipeline. As a result, electronic devices connected to the pipeline can be affected unless they are
adequately grounded.
Contaminant Gases: A gas scrubber and flow indicator with integral metering valve are required upstream of the
analyzer to remove any interfering gases such as oxides of sulfur and nitrogen or hydrogen sulfide that can interfere
with measurement and cause reduction in the expected life of the sensor. Consult the factory for recommendations
concerning the proper selection and installation of components.
Expected Sensor Life: With reference to the publish specification located at the last page of this manual, the expected
life of all oxygen sensors is predicated on oxygen concentration in ambient air, temperature (77°F/25°C) and pressure
(1 atmosphere) in “normal” applications. Deviations from standard conditions will affect the life of the sensor. As a rule
of thumb sensor life is inversely proportional to changes in the pressure and temperature.
Accuracy & Calibration: Refer to section 5 Operation.
Operating Temperature: The sample must be sufficiently cooled before it enters the analyzer and any optional
components. A coiled 10 foot length of ¼” stainless steel tubing is sufficient for cooling sample gases as high as 1,800
ºF to ambient. The recommended operating temperature is below 35 ºC. However, the analyzer may be operated at
temperature up to 45 ºC on an intermittent basis but the user is expected to accept a reduction in expected sensor life –
as a rule of thumb, for every degree ºC increase in temperature (above 25 ºC), the sensor life is reduced by
approximately 2.5%.
Heat: Situate and store the analyzer away from direct sources of heat.
Liquid and Object Entry: The analyzer should not be immersed in any liquid. Care should be taken so that
liquids are not spilled into and objects do not fall into the inside of the analyzer.
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Handling: Do not use force when using the switches, knobs or other mechanical components. Before moving your
analyzer be sure to disconnect the wiring/power cord and any cables connected to the output terminals of the analyzer.
Sample Pressure and Flow
All electrochemical oxygen sensors respond to partial pressure changes in oxygen. The sensors are equally capable of
analyzing the oxygen content of a flowing sample gas stream or monitoring the oxygen concentration in ambient air
(such as a confined space in a control room or an open area around a landfill or bio-pond). The following is applicable
to analyzers equipped with fuel cell type oxygen sensors.
Analyzers designed for in-situ ambient or area monitoring has no real sample inlet and vent. The sensor is exposed
directly to the sample gas and it is intended to operate at atmospheric pressure. The analyzer has a built-in pressure
sensor and the sensor output is automatically compensated for any atmospheric pressure changes.
Inlet Pressure: For the analyzers designed to measure oxygen in a flowing gas stream, the inlet sample pressure
must be regulated between 5-30 psig. Although the rating of the SS tubing and tube fittings/valves itself is considerably
higher (more than 100 psig), a sample pressure of 5-30 psig is recommended for ease of control of sample flow.
The analyzer equipped with a sample system has designated SAMPLE and VENT ports. Connect SAMPLE gas to
SAMPLE and the vent to the VENT ports only.
Caution: If the analyzer is equipped with an optional H2S scrubber, sample inlet pressure must not exceed
30 psig.
Outlet Pressure:In applications where sample pressure is positive, the sample must be vented to an exhaust
pipe at a pressure less than the inlet pressure so that the sample gas can flow through the sensor housing. Ideally, the
sample must be vented to atmospheric pressure.
Note: The sensor may be used at a slight positive pressure (e.g., when sample is vented to a common exhaust where
the pressure might be higher than 1 atmosphere). However, the pressure at the sensor must be maintained at all times
including during the span calibration. This may be accomplished by using a back-pressure regulator at vent line of the
analyzer. Caution: A sudden change in pressure at the sensor may result in the sensor electrolyte leakage.
Flow rates of 1-2 SCFH cause no appreciable change in the oxygen reading. However, flow rates above 5 SCFH may
generate a slight backpressure on the sensor resulting in erroneous oxygen readings.
Caution: Do not place your finger over the vent (it pressurizes the sensor) to test the flow indicator when
gas is flowing to the sensor. Removing your finger (the restriction) generates a vacuum on the sensor and
may damage the sensor (voiding the sensor warranty).
Application Pressure - Positive:A flow indicator with integral metering valve positioned upstream of the
sensor is recommended for controlling the sample flow rate between 1-5 SCFH. If a separate flow control valve and a
flow indicator is used, position flow control valve upstream of the sensor and position a flow indicator downstream of
the sensor. If necessary, a pressure regulator upstream of the flow control valve should be used to regulate the inlet
pressure between 5-30 psig.
Caution: If the analyzer is equipped with a H2S scrubber as part of an optional sample conditioning system, inlet
pressure must not exceed 30 psig.
Application Pressure - Atmospheric or Slightly Negative: For % oxygen measurements, an
optional external sample pump may be used upstream of the sensor to push the sample across the sensor and out to
atmosphere. For PPM oxygen measurements, an optional external sampling pump should be positioned downstream
of the sensor to draw the sample from the process, by the sensor and out to atmosphere. A flow meter is generally not
necessary to obtain the recommended flow rate with most sampling pumps. However, if the sample pump can
pull/push more than 5 SCFH, a flow control must be used to control the sample flow. The flow control valve must be
positioned in such a way that it does not generate any vacuum on the sensor.
Caution: If the analyzer is equipped with a flow indicator with integral metering valve or a metering flow
control valve upstream of the sensor and the pump is installed downstream of sensor- open the metering
valve completely before turning the pump ON to avoid drawing a vacuum on the sensor and placing an
undue burden on the pump.
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If pump loading is a consideration, a second throttle valve on the pump’s inlet side may be necessary to provide a
bypass path so the sample flow rate is within the above parameters.
Moisture & Particulates: Installation of a suitable coalescing or particulate filter is required to remove
condensation, moisture and/or particulates from the sample gas to prevent erroneous analysis readings and damage to
the sensor or other optional components. Moisture and/or particulates do not necessarily damage the sensor. However,
collection of moisture/particulate on the sensing surface can block or inhibit the diffusion of sample gas into the sensor
resulting in a reduction of sensor signal output – and the appearance of a sensor failure. Consult the factory for
recommendations concerning the proper selection and installation of optional components.
Moisture and/or particulates generally can be removed from the sensor by opening the sensor housing and either
blowing on the sensing surface or gently wiping or brushing the sensing surface with damp cloth. Caution: Minimize
the exposure of PPM sensors to air during this cleaning process. Air calibration followed by purging with zero or a gas
with a low PPM oxygen concentration is recommended after the cleaning process is completed.
Mounting: The analyzer is approved for indoor as well as outdoor use. However, avoid mounting in an area where
direct sun might heat up the analyzer beyond the recommended operating temperature range. If possible, install a
small hood over the analyzer for rain water drain and to prevent over-heating of analyzer..
Gas Connections: The Inlet and outlet vent gas lines require 1/8” or ¼” stainless steel compression type tube
fittings. The sample inlet tubing must be metallic, preferably SS. The sample vent line may be of SS or hard plastic
tubing with low gas permeability.
Power: Supply power to the analyzer only as rated by the specification or markings on the analyzer enclosure. The
GPR-2500 is a two wire loop powered analyzer. To comply with the ATEX Directives 94/9/CE, power to the transmitter
must be provided via an approved intrinsic safety barrier MTL 7706+ or equivalent.
WARNING: TRANSMITTER RATING FOR USE IN HAZARDOUS AREA WILL VOID WITHOUT THE USE OF
INTRINSIC SAFETY BARRIER
The input power must be between 24-28 VDC. The wiring that connects the analyzer to the power source should be
installed in accordance with recognized electrical standards. Ensure that the analyzer case is properly grounded and
meets the requirements for area classification where the analyzer is installed. Never yank wiring to remove it from a
terminal connection.
The two wire loop powered analyzers consume no more than 0.68 Watts of power.
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4. Features & Specifications
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5. Operation
Principle of Operation
The GPR-2500 Oxygen Transmitter incorporates a variety of advanced galvanic fuel cell type oxygen sensors. These
sensors are very specific to oxygen and generate an electrical signal proportional to the amount of oxygen present in a
gas stream. The selection of a particular type of sensor depends on the composition of the sample gas stream. Consult
the factory for recommendation.
The signal processing electronics and sensor are housed in a general purpose NEMA 4X rated enclosure. The
terminals for incoming power, signal output and intrinsic safety barriers are mounted on a PCB housed in an explosion
proof enclosure.
The intrinsic safety barriers MTL7706+ or equivalent, limits the amount of power that flows to and from the signal
processing electronics to a safe level effectively preventing an explosive condition. The analyzer design conforms to
the ATEX Directive 94/9/CE for equipment as intrinsically safe and has been approved by an independent body: EC
Type Examination Certificate: INERIS 08ATEX0036
The analyzer carries the following area classification
II 2 G,
Ex ia IIB T4 Gb
Tamb -20⁰C to +50⁰C
WARNING: POTENTIAL ELECTROSTATIC CHARGING HAZARD-SEE INSTRUCTION
The GPR-2500 also meets the intrinsic safety standards required for use in Class 1, Division 1, Group C, D hazardous
areas.
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Advanced Galvanic Sensor Technology
All galvanic type sensors function on the same principle and are specific to oxygen. They measure the partial pressure
of oxygen from low PPM to 100% levels in inert gases, gaseous hydrocarbons, helium, hydrogen and mixed gases
Oxygen, the fuel for this electrochemical transducer, diffusing into the sensor, reacts electrochemically at the sensing
electrode to produce an electrical current output proportional to the oxygen concentration in the gas phase. The
sensor’s signal output is linear over all measuring ranges and remains virtually constant over its useful life. The sensor
requires no maintenance and is easily and safely replaced at the end of its useful life.
Proprietary advancements in design and chemistry add significant advantages to this extremely versatile oxygen
sensing technology. Sensors for low % analysis recover from air to low % levels in seconds, exhibit longer life and
reliable quality. The expected life of our new generation of percentage range sensors now range from 32 months to ten
years with faster response times and greater stability. Another significant development involves expanding the
operating temperature range for percentage range sensors from -20°C to 50°C. Contact factory for more specific
information about your application.
Electronics
The signal generated by the sensor is processed by state of the art low power micro-processor based digital circuitry.
The first stage amplifies the signal. The second stage eliminates the low frequency noise. The third stage employs a
high frequency filter and compensates for signal output variations caused by ambient temperature changes. The result
is a very stable signal. Sample oxygen is analyzed very accurately. Response time of 90% of full scale is less than 10
seconds (actual experience may vary due to the integrity of sample line connections, dead volume and flow rate
selected) on all ranges under ambient monitoring conditions. Sensitivity is typically 0.5% of full scale of the low range.
Oxygen readings may be recorded by an external device via the 4-20 mA or 1-5V signal output.
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Sample System:
The standard GPR-2500 is supplied without a sample conditioning system thereby giving users the option of adding
their own or purchasing a factory designed sample conditioning system, see section 2 QC Certification for optional
equipment ordered. Whatever the choice, the sample must be properly conditioned before introducing it to the sensor
to ensure an accurate measurement.
The GPR-2500 is generally supplied with a minimum of a sample flow control valve and a flow meter. Users interested
in adding their own sample conditioning system should consult the factory. Advanced Instruments Inc. offers a full
range of sample handling, conditioning and expertise to meet your application requirements. Contact us at 909-392-
6900 or e-mail us at [email protected].
Calibration & Accuracy Overview
Single Point Calibration: As previously
described the galvanic type oxygen sensor
generates an electrical current proportional to the
oxygen concentration in the sample gas. In the
absence of oxygen the sensor exhibits an
absolute zero, e.g. the sensor does not
generate a current output in the absence of
oxygen. Given these linearity and absolute zero
properties, single point calibration is possible.
Pressure: Because sensors are sensitive to the
partial pressure of oxygen in the sample gas, their
output is a function of the number of molecules of
oxygen or percentage 'per unit volume'.
Temperature: The rate at which oxygen
molecules diffuse into the sensor is controlled by a
Teflon membrane otherwise known as an 'oxygen diffusion limiting barrier' and all diffusion processes are temperature
sensitive, the fact the sensor's electrical output will vary with temperature is normal. This variation is relatively constant
(2.5% per ºC). A temperature compensation circuit employing a thermistor and a network of resisters offsets this effect
with an accuracy of +5% or better over a wide operating temperature range e.g., 5-45 oC can be obtained thus the
signal output remains virtually independent of ambient temperature. There is extremely low error in measurement if the
calibration and sampling are performed at similar temperatures (within +/- 5 ºC. Conversely, a temperature variation of
10 ºC may produce an error of >2% of full scale.
Accuracy: In light of the above parameters, the overall accuracy of an analyzer is affected by two types of errors: 1)
'percent of reading errors', illustrated by Graph A below and 2) 'percent of full scale errors', illustrated by Graph B, such
as1-2% errors in readout and calibration devices. Other errors are 'spanned out' during calibration, especially when
analyzer is calibrated close to the top end of the measuring range.
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Mounting the Transmitter
The GPR-2500 analyzer consists of two interconnected enclosures (without the optional sample conditioning system
and panel) and measures 8”H x 15-3/4”W x 7”D. This configuration is designed to be mounted directly to any flat
vertical surface, wall or bulkhead plate by using four (4) appropriate screws.
To facilitate servicing the interior of the transmitters, secure the transmitter to a vertical surface approximately 5 feet
from the floor or a level accessible to service personnel. This requires the user to supply four (4) additional proper size
screws and anchors.
To mount the transmitter, remove the four screws from the front door of the transmitter. Lift the door up. Use four
screws/anchors and install the transmitter on a smooth vertical flat surface/wall.
Caution: Do not remove or discard the gaskets from the enclosure. Failure to reinstall the gaskets will void
the NEMA 4 rating and the immunity to RFI/EMI.
The transmitters design provides immunity from RFI/EMI by maintaining a good conductive contact
between the two halves of the enclosures via a conductive gasket (the smaller enclosure containing. The surfaces
contacting the conductive gasket are unpainted. Do not paint these areas. Painting will negate the RFI/EMI protection.
Remove four
screws and lift the
door up to access
mounting holes
Sample In and
Sample Out
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Gas Connections
The GPR-2500 with its standard flow through configuration is designed for positive pressure samples and requires
connections for incoming sample and outgoing vent lines. Zero and span inlet ports are offered as part of the optional
sample systems. The user is responsible for calibration gases and other required components, see below.
Procedure
Caution: Do not change the factory setting until instructed to do in this manual.
If analyzer has no marking for sample inlet and sample vent, designate one of the bulkhead tube fittings as the VENT
and the other as SAMPLE IN.
Regulate the sample pressure as described in “Pressure and Flow” section above.
Connect a 1/8” or a¼” vent line to the compression fitting to be used for venting the sample.
Connect a 1/8” or ¼” sample line to the compression fitting to be used to bring SAMPLE gas to the analyzer.
If equipped with optional SPAN and/or ZERO ports, connect the SPAN and the ZERO gas lines to the respective SPAN
and ZERO ports of the analyzer
Set the SAMPLE, SPAN and the ZERO gas pressure between 5-30 psig..
Select sample gas and allow it to flow through the transmitters and set the flow rate to1- 2 SCFH.
Note: If equipped with the optional H2S sample conditioning system: Regulate the pressure so that it does not exceed
30 psig.
Sample Flow Rate
Flow rates of 1-2 SCFH cause no appreciable change in the oxygen reading. However, flow rates above 5 SCFH may
generate a backpressure and cause erroneous oxygen readings due to fact that the smaller diameter of the integral
sample system tubing cannot vent the sample gas quickly at higher flow rates. If the analyzer is not equipped with an
integral flow control valve, a flow control metering valve with a flow indicator upstream of the sensor must be installed
to control the flow rate of the sample gas. A flow rate of 1-2 SCFH or 0.5-1 liter per minute is recommended for
optimum performance.
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Electrical Connections
Incoming power and signal output connections are made to a terminal block mounted inside a small
enclosure attached on the side of the main enclosure. Bring power cable through the cable gland and
secure the lugs of the cable to the terminal block as shown below. Connect the positive wire to the plus
terminal and minus wire to the minus terminals of the terminal block.
Do not supply voltage more than specified in this manual and noted near the power input terminal of the
transmitter.
In order to maintain the intrinsic safety of the transmitter, the power must be supplied through an ATEX approved
intrinsic safety barrier. The factory recommended intrinsic safety barrier is MTL 7706+ or equivalent.
Without the use of intrinsic safety barrier or use of an improper safety barrier will void intrinsic safety rating (see below)
of the transmitter.
The transmitter must be grounded by making a ground connection with the screw terminal marked as Ground.
With intrinsically safe power, this configuration of the GPR-2500 conforms to the ATEX Directives 94/9/CE for
equipments for use in hazardous area. The analyzer meets the following area classification:
II 2 G
Ex ia IIB T4 Gb
Tamb -20⁰C to +50⁰C
Avoid electrostatic discharge – Clean all non-metallic surfaces with a damp cloth only.
With the use of recommended intrinsic safety barrier, the GPR-2500 also meets the intrinsic safety standards required
for use in Class 1, Division 1, Group C, D hazardous areas.
Connect ground
terminal to Ground
Power 24-28 V DC
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Installation in Hazardous Area
The GPR-2500 may be installed in a hazardous area. However, in order to maintain the intrinsic safety rating of the
transmitter, total power coming to the transmitter must be limited to a safe level. This can be achieved by using the
recommended safety barrier, MTL7706+ or equivalent. The intrinsic safety barrier has a built in power limiting circuitry
that keeps the maximum power going to the transmitter to a safe level even under fault conditions.
The maximum supply to the safety barrier is limited to 36 volts but the lowest voltage required is 24 VDC.
The intrinsic safety barrier must be installed in a safe area.
Output Connection
The 4-20mA current output is measured in the power loop by connecting a current measuring device between the
negative terminal of the power source and the negative terminal, marked (-), of the power input terminal block located
in the small enclosure. The current flow is from positive terminal of the power source to the positive terminal of the
transmitter and back to the negative terminal of the power source.
To measure the 4-20 mA signal output, connect an ammeter, as illustrated below. To convert the 4-20 mA in to 1-5
VDC, place a 250 Ohms resister in place of the current meter and measure the voltage across the resister.
24-28VDC
+++
_ _ _
Current Measuring Device Intrinsic Safety Barrier
4-20 mA MTL7706+ or Equivalent
4-20 mA Measuring Device Transmitter
Caution: To prevent accidental damage to the Intrinsic Safety Barrier, it is highly recommended that an
additional Fuse rated at 100 mA at 30 VDC be placed ahead of the intrinsic safety barrier.
Procedure
Power requirements consist of a two wire shielded cable, intrinsic safety barrier and a 24-36 V DC power supply.
Mount the intrinsic safety barrier on the din rail or other mounting device and ensure that the mounting bracket of the
intrinsic safety barrier is connected to the ground.
Connect the power to the two terminals of the intrinsic safety barrier marked as SAFE (terminal 1 + and terminal 2 -)
Connect a two wire shielded cable to the two terminals of the intrinsic safety barrier marked as HAZ (terminal 3 + and
terminal 4 -)
Run the shielded cable from HAZ through a proper conduit and through the cable gland and connect the two ends of
the shielded cable to the two terminals of the transmitter marked as + and –
Replace the cover of the small power input enclosure.
Connect the ground terminal of the transmitter to a proper ground.
Connect the ground of the safety barrier to the mounting rail (without rail ground, the transmitter will not power up)
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Installing Oxygen Sensor
The GPR-2500 Oxygen Transmitter is equipped with an integral flow-through Delrin adopter with SS fittings and tubing.
The oxygen sensor simply screws in the adopter. The seal between the flow-through adopter and the oxygen sensor is
achieved by an integral o-ring (over the threaded spout) and the steeped sealing surface of the flow-through adopter.
Optional stainless steel sensor housing is available for oxygen measurements in highly corrosive applications.
The transmitter has been tested and calibrated by the manufacturer prior to shipment and is fully operational from the
shipping container.
Caution: All transmitters must be calibrated once the installation has been completed and periodically
thereafter as described below. Following the initial installation and calibration, allow the transmitters to
stabilize for 1-2 hours and re-calibrate the transmitter with a certified span gas.
Caution: DO NOT dissect the oxygen sensor. The sensor contains a corrosive liquid electrolyte that could be harmful if
touched or ingested, refer to the Material Safety Data Sheet in Section 10. Avoid contact with any liquid or
crystal type powder in or around the sensor or sensor housing, as either could be a form of electrolyte.
Leaking sensors should be disposed off in a manner similar to that of a common battery in accordance with
local regulations.
Avoid Electrostatic Discharge – Clean all non-metallic surfaces with a damp cloth only.
Procedure
1. Remove the four (4) screws securing the lid of the transmitter to the bottom of the enclosure.
2. Lift the door up until you hear a “click” sound (the hinge of the door will look itself thus preventing the door
from falling back). Caution: Do not remove the gaskets from either the enclosure. Failure to reinstall the
gasket will void the NEMA 4 rating and EMI/RFI protection.
3. Remove the oxygen sensor from the bag.
4. Remove the spring from inside of the round metal connector of the sensor (the spring keeps the positive and
negative terminals of the sensor shorted to ensure that sensor is ready to use in a relatively short period of
time after installation). Note: After removing the spring, the sensor must be connected to the sensor cable
immediately. Failure to do so will prolong the time the sensor will require to stabilize.
5. Screw the oxygen sensor into the sensor housing. Finger tighten plus one eighth (1/8) turn to ensure a good
seal between the sensor housing and the o-ring affixed to the sensor.
6. Assure the keyway registration of the female plug on the cable and male receptacle on the sensor match up.
7. Push the female plug (including the knurled lock nut) molded to the cable into the male receptacle attached to
the new sensor.
8. Screw the knurled lock nut attached with the cable onto to the male connector of the sensor.
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9. Close the door of the enclosure and tighten the four screws assuring that the gasket is firmly in place between
the door and the body of the enclosure.
10. Proceed to calibration.
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Span Gas Preparation
The GPR-2500 can be calibrated by using ambient air. However, it can also be calibrated by using a certified span gas.
Air calibration can be achieved right after installing the sensor in the housing. Subsequent calibration, where the sensor
has been exposed to a sample gas, air calibration can be achieved by either removing the sensor from the sensor
housing or by pushing the air through the sensor housing.
Establishing Power
Once the two power input wires of the shielded cable are properly connected to the terminals inside the enclosure as
described above, connect the other end of the two wires to a suitable 24-28 VDC power supply such as a battery, PLC,
DCS, etc.
The digital display responds instantaneously. When power is applied, the transmitter performs several self-diagnostic
system status checks termed as “START-UP TEST” as illustrated below:
START-UP TEST
ELECTRONICS – PASS
BATTERY- PASS
TEMP SENSOR – PASS
BARO SENSOR – N/A
S1010 1.17
After self diagnostic tests, the analyzer turns itself into the sampling mode. And displays oxygen contents the sensor is
exposed to, the analysis range, and the ambient temperature.
20.9%
AUTO SAMPLING
25% RANGE
76 F
Menu Navigation
The four (4) pushbuttons located on the front of the transmitter control all of the micro-processor functions:
Blue ENTER (select)
Yellow UP ARROW
Yellow DOWN ARROW
Green MENU (escape)
Main Menu
To access the MAIN MENU, press the MENU (ESC) key and the following screen will appear.
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MAIN MENU
SELECT RANGE
CALIBRATION
VIEW HISTORY
SYSTEM OPTIONS
This screen show various option available. You can use the UP and DOWN arrow key to move the cursor and highlight
the desired function. After moving the cursor to the desired function, you can press ENTER to get to that function
The GPR-2500 analyzer is equipped with four (4) standard measuring ranges (see specification) and provides users
with a choice of sampling modes. By accessing the MAIN MENU, users may select either the AUTO SAMPLING
(ranging) or MANUAL SAMPLING (to lock on a single range) mode.
Auto/Manual Sampling
Access the MAIN MENU by pressing the MENU key.
Advance the reverse shade cursor using the ARROW keys to highlight SELECT RANGE and press ENTER
The display will show *AUTO and the actual range of analysis. Press the ENTER to select MANUAL RANGE and
advance the cursor to the desired RANGE and press ENTER.
The following display appears:
MAIN MENU
SELECT RANGE
CALIBRATION
VIEW HISTORY
SYSTEM OPTIONS
SELECT RANGE
*AUTO
25%
10%
5%
*1%
76 F
In the AUTO range, the display will shift to the next higher range when the oxygen reading exceeds 99.9% of the upper
limit of the current range. The display will shift to the next lower range when the oxygen reading drops to 85% of the
upper limit of the next lower range. In MANUAL range, the analyzer will be locked on the selected range. If the oxygen
value goes above 25% of the upper limit of the MANUAL selected range, an OVER RANGE warning will be displayed.
1.25 %
OVERRANGE
MANUAL SAMPLING
1% RANGE
76 F
Once the OVER RANGE warning appears the user must advance to the next higher range.
NOTE: With oxygen reading above 25% of the selected range, the analog signal output will increase but will freeze at a
maximum value of 1.2 V. After the oxygen reading falls below the full scale range, the voltage signal will become
normal.
Analyzer Calibration
The electrochemical oxygen sensors generate an electrical current that is linear or proportional to the oxygen
concentration in a sample gas. In the absence of oxygen the sensor exhibits an absolute zero, i.e., the sensor does
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