Analytical Industries GPR-1500 A User Manual

Advanced Instruments Inc.
GPR-1500-A PPM Oxygen Transmitter
Owner’s Manual
2855 Metropolitan Place, Pomona, California 91767 USA Tel: 909-392-6900, Fax: 909-392-3665, e­mail: info@aii1.com
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 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.
Appendix B
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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
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-1500IS Oxygen Transmitter. Additional precautions specific to individual transmitter are contained in the following sec tions 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 O wner’s Manu al 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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2. Quality Control Certification
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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 arou nd the sensor or sensor housing, as either could be a form of electrolyte. Leaking sensors should be disposed of in accordance with loc al 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 pers onnel.
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 range 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 : 2006 EN 60079-1 : 2004
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 install ation. 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 requir ed 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 compone nts.
Expected Sensor Life: With reference to the publish specification located at the last page of this manu al, the expected life of all oxygen sensors is predicated on oxygen concentration (< 1000 PPM for PPM sensor or air for % sensor), 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.
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Materials: Assemble the necessary zero, sample and span gases and optional components such as valves, coalescing or particulate filters, and pumps as dictated by the application. Stainless steel tubing is esse ntial for maintaining the integrity of the gas stream for low % or PPM O
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.
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 ca bles connected to the output terminals of the analyzer.
level analysis.
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Sample Pressure and Flow
All electrochemical oxygen sensors respond to partial pressure cha nges 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 arou nd a landfill or bio-pond). The following is applicable to analyzers equipped with fuel cell type oxyg en 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 back­pressure 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 1-5 SCFH cause no appreciable change in the oxygen reading. Ho wever, flo w rates above 5 SCFH may generate a slight backpressure on the sensor resulting in erroneous oxygen readings.
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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.
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 concerni ng 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 brushin g 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.
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Power: Supply power to the transmitter only as rated by the specification or markings on the analyzer
enclosure. The GPR-1500-A is a DC powered analyzer. The input power must be between 12-24 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 transmitter consumes no more than 7 Watts of power.
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4. Features & Specifications
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5. Operation Principle of Operation
The GPR-1500-A Oxygen Transmitter incorporates 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 transmitter is configured with two integral electronic PCB. The signal processing electronics PCB and the power supply, signal output, and alarm relays PCB are housed in a metal enclosure. The two PCBs are interconnected via a ribbon cable.
Clean all surfaces with a damp cloth to avoid electrostatic discharge.
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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 concentratio n in the gas phase. The sensor’s signal output is linear over all measuring ranges and remains virtual ly 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 -30°C to 50°C. Contact factory for more specific information about your application.
The PPM sensors recover from an upset condition to low PPM level in a matter of few minutes. These sensors show excellent stability over its useful life.
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 cause d b y ambient temperature changes. The result is a very stable signal. Sample oxygen is analyz ed 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 (by converting 4-20 mA in to voltage signal by using a 250 oh ms resistor) signal output.
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Sample System
The standard GPR-1500-A transmitter is supplied without a sample conditioning s ystem thereby giving users the option of adding their own or purchasing a factory designed sample conditi oning 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.
Users interested in adding their own sample conditioning system should consult the factory. Advance d 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 info@aii1.com
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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 'per unit volume'. Readouts in percent are permissible only when the total pressure of the sample gas being analyzed remains constant. The pressure of the sample gas and that of the calibration gas must be the same.
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 + range e.g., 5-45 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:
errors: 1) 'percent of reading errors', illustrated by Graph A below, is contributed by the temperature compensation tolerances in resistors values and the accuracy in the measuring devices, e.g., LCD display and 2) 'percent of full scale errors', illustrated by Graph B, such as1-2% offset 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.
Graph C illustrates these 'worse case' specifications that are typically used to develop an overall accuracy statement of < 1% of full scale at constant temperature or < 5% over the operating temperature range. The QC testing error is typically < 0.5% prior to shipment of analyzer from the factory.
o
C can be obtained thus the signal output remains virtually independent of ambient
In light of the above parameters, the overall accuracy of an analyzer is affected by two types of
circuit (tolerance in the thermistor value, variation in temperature coefficient of the thermistor,
5% or better over a wide operating temperature
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Example 1: As illustrated by Graph A, any error during a span adjustment at lower end of the scale, e.g.,
20.9% (air) on a 100% full scale range, would be multiplied by a factor of 4.78 (100/20.9) when making measurements close to 100% O2. Conversely, an error during a span adjustment close to the top end of the range, e.g., at 100% is reduced proportionately for measurements of oxygen concentrations near the bottom end of the range.
Graph B represents a constant error over the entire measuring range. This error is generally associated with the measuring e.g., LCD and or calibrating devices, e.g., current simulator or current/voltage measuring devices.
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Mounting the Transmitter
The GPR-1500-A consists of metal enclosure and a sensor housing (without any optional sampl e conditioning system) and measures 7”H x 4”W x 4.5”D. This configuration is designed to be mou nted directly to any flat vertical surface or bulkhead plate by using four (4) mounting studs at the back of front panel..
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) 6-32 hex nuts.
Caution: Do not remove or discard the gaskets
around the front panel. Failure to reinstall the gaskets will allow dust and/or moisture condensate to accumulate on the electronics PCBs and cause possible failure.
The transmitters design provides immunity from RFI/EMI by maintaining a good conductive contact between the transmitter enclosure and a good ground. Ensure that ground is connected to the rear of the enclosure marked with the symbol ground..
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Gas Connections
The GPR-1500-A with its standard flow through sensor housing configuration is designed for positive pressure samples and requires connections for incoming sample and outgoing vent lines. The user should adhere to the recommendation in terms of using the type of fittings, tubing, sample/span/zero gas pressure and sample flow rates. Failure to do so may cause permanent damage to the sensor.
Procedure:
Caution: Do not change the factory setting until instructed to do in this manual.
1. 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.
2. Regulate the sample pressure as described in “Pressure and Flow” section above.
3. Connect a 1/8” or a ¼” vent line to the compression fitting to be used for venting the sample.
4. Connect a 1/8” or ¼” sample line to the compression fitting to be used to bring SAMPLE gas to the
analyzer.
5. 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
6. Set the SAMPLE, SPAN and the ZERO gas pressure between 5-30 psig..
7. Select sample gas and allow it to flow through the transmitters and set the flow rate to1- 2 SCFH.
Flow rates of 1-5 SCFH cause no appreciable change in the oxygen reading. Ho wever, flo w 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 1­2 SCFH or 0.5-1 liter per minute is recommended for optimum performance.
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 sudden vacuum on the sensor and may lead to electrolyte leakage thus causing damage to the
sensor (will void sensor warranty).
Electrical Connections
Incoming power and signal output connections are made to terminal blocks mounted on a PCB located in the metal enclosure and accessible from the rear of the enclosure.
Do not supply voltage more than specified in this manual and noted near the power input terminal of the transmitter.
Install all power, alarm relay and signal output connections in accordance with recognized electrical standards. Supply power to the terminal marked “POWER”. Do not exceed the recommended power rating.
Ensure the positive and negative terminals of the power supply are connected to the appropriate terminals of the terminal block as marked.
Avoid electrostatic discharge - Clean all surfaces with a damp cloth only.
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The transmitter is equipped with a safety fuse rated at 1A 250 V (Manufacturer, Littelfuse, Part Number 370-
1100). When replacing the fuse, use a compatible fuse only ( described above).
Power Fuse Transmitter Ground 12-24 VDC 1 A, F type
Note: The male and female terminals snap together. Ensure that the male terminal is fully inserted and secured into the female terminal block.
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Installing the Oxygen Sensor
The GPR-1500-A Oxygen Transmitter is equipped with a SS sensor housing. This housing offers ease of replacement of sensor and at the same time prevents any air leakage into the system. The two sections of the sensor are held together by a metal clamp secured in place by easily accessed bolt. The integrity of the sensor housing has been tested at the factory 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 12-24
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 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 off in a manner similar to that of a common battery in accordance with local regulations.
Avoid electrostatic discharge – Clean all surfaces with a damp cloth only.
Procedure
1. Loosen the bolt at the bottom of the sensor housing by using 5/16 ranch provided.
2. Twist the upper section of the housing 90 degree and pull it up until it clears the bottom section of the
sensor housing.
3. Remove the old sensor (if previously installed) from the sensor housing
4. Remove the oxygen sensor from the bag and remove the two red shorting taps from the two ring gold
color contact plate of the sensor.
Remove the two red ribbons from sensor PCB
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5. Insert the sensor into the upper section of the sensor housing with gold contact plate facing towards two
gold contact pins of the sensor housing
6. By holding the sensor and the upper section of the sensor housing in your hand, allow 2-3 minutes for
the analyzer to respond to the new sensor. The analyzer should disp lay oxygen around 21% with factory default span setting (see below)
7. You may perform a quick air calibration at this time (see details in the “Calibration” ) to ensure that the
analyzer accepts the air calibration thus confirming that the sensor output is within the recommended limits.
8. Place the sensor in the bottom section of the sensor housing with the two ring gold contact plate facing
up. Place the upper section of the sensor housing over the sensor. Slightly push it down and twist 90 degree.
9. By using the 5/16 ranch, tighten the bolt securing the two section together.
Hold the sensor pressed against the contact pins inside the housing
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Span Gas Preparation
Note: The GPR-1500-A transmitter can be calibrated by using ambient air. Ho wever, 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 sampl e gas, air calibration can be achieved by either removing the sensor from the sensor housing or by pushing the air through th e sensor housing.
Caution: Do not contaminate the span gas cylinder when installing the pressure regulator on the span gas cylinder. Further, bleed the air filled regulator and span gas tubing before connecting the span gas to the analyzer and attempting the initial calibration.
Required Components
1. Certified span gas cylinder with an oxygen concentration, balance nitrogen, approximating 80% of the
full scale of the measuring range or one range above the intended measuring range.
2. A pressure regulator to set the span gas pressure between 5 and 30 psig.
3. A flow meter to set the flow between 1-5 SCFH.
4. Suitable tube fittings and a 4-6 ft. length of 1/8” dia. metal tubing to connect the regulator to the flow
meter inlet (flow meter supplied by the user).
5. Suitable tube fittings and a 4-6 ft. length of 1/8” dia. metal tubing to connect from the flow meter vent to
tube fitting of the sensor housing.
Procedure
1. With the span gas cylinder valve closed, install the pressure regulator on the cylinder.
2. Open the regulator’s exit valve and partially open the pressure regulator’s control knob.
3. Open slightly the cylinder valve.
4. Loosen the nut connecting the regulator to the cylinder and bleed the pressure regulator.
5. Retighten the nut connecting the regulator to the cylinder
6. Adjust the regulator exit valve and slowly bleed the pressure regulator.
7. Open the cylinder valve completely.
8. Set the pressure between 5-30 psig using the pressure regulator’s control knob.
Caution: Do not exceed the recommended flow rate. Excessive flow rate could cause the backpressure on the sensor and may result in erroneous readings and damage to the sensor
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Establishing Power to Electronics
Once the 12-24 VDC power is supplied, the digital display responds instantaneo usly. The transmitter performs several self-diagnostic system status checks termed as “START-UP TEST” as illustrated below:
START-UP TEST
ELECTRONICS – PASS TEMP SENSOR – PASS BAROMETRIC SENSOR – PASS
REV. 2.14
After self diagnostic tests, the analyzer turns itself into the sampling mode. And displays oxygen contents the sensor is exposed to, the analysis range, the ambient temperature and pressure.
0.3 %
AUTO SAMPLING
0-1% RANGE
76 F 100 KPA
Menu Navigation
The four (4) pushbuttons located on the front of the transmitter control 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.
MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE CALIBRATION CONFIG ALARMS BYPASS ALARMS
This screen shows various options 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, press ENTER to access that function.
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Range Selection
The GPR-1500-A transmitter is equipped with four (5) 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.
Note: For calibration purposes, use of the AUTO SAMPLE mode is recommended. For example, calibration with ambient air (20.9% oxygen), the analyzer will automatically turn into 0-25% range. However, the user can also select the MANUAL SAMPLE mode for calibration but the span gas must not exceed the full scale of the manual range selected – for example, a span gas with an 80 PPM oxygen concentration in nitrogen would dictate the use of the 0-100 PPM full scale range for calibration.
Auto Sampling
Access the MAIN MENU by pressing the MENU key. Advance the reverse shade cursor using the ARROW keys to highlight AUTO SAMPLE. Press the ENTER key to select the highlighted menu option. The display returns to the sampling mode:
MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE CALIBRATION CONFIG ALARMS BYPASS ALARMS
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 next lower range.
For example, if the transmitter is reading 1PPM on the 0-10 PPM range and an upset occurs, the display will shift to the 0-100 PPM range when the oxygen reading exceeds 9.9 PPM. Conversely, once the upset condition is corrected, the display will shift back to the 0-10 PPM range when the oxygen reading drops to
8.5 PPM.
0.3 %
AUTO SAMPLING 1% RANGE
76 F 100 KPA
Manual Sampling
Access the MAIN MENU by pressing the MENU key. Advance the reverse shade cursor using the ARROW keys to highlight MANUAL SAMPLE. Press the ENTER key to select the highlighted menu option. The following display appears:
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MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE
CALIBRATION CONFIG ALARMS BYPASS ALARMS
Advance the reverse shade cursor using the ARROW keys to highlight the desired MANUAL RANGE. Press the ENTER key to select the highlighted menu option. The following display appears with the range selected and o x ygen concentration of the sample gas:
MANUAL RANGE
25%
1%
1000 PPM 100 PPM 10 PPM
If the oxygen value goes above the full scale range selected, display will not shift to the next higher range. Instead, when the oxygen reading exceeds 110% of the upper limit of the current range, an OVER RANGE warning will be displayed.
MANUAL RANGE
>>>
>>>
25% 1% 1000 PPM 100 PPM 10 PPM
0.3 %
MANUAL RANGE
0-1% RANGE
76 F 100 KPA
12.5 PPM
OVERRANGE
MANUALRANGE
10 0-10 PPM RANGE
76 F 100 KPA
Once the OVER RANGE warning appears the user must advance the transmitter to the next higher range. NOTE: With oxygen reading above 110% of the selected range, the mA signal output will increase but will
freeze at a maximum value of 24 mA. After the oxygen reading falls below the full scale range, the mA signal will become normal.
Calibration of Transmitter
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 not generate a current output in the absence of oxygen. Given the properties of linearity and an absolute zero, a single point calibration is possible.
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The transmitter is equipped with a “Zero Calibration” feature. However, as described below, zero calibration is recommended only when the application (or user) demands optimum accuracy of belo w 5% of the most sensitive or lowest range available on the transmitter. For example, if the user requires analysis of a sample gas below 0.5 PPM, a zero calibration is recommended.
Span calibration, in one of the forms described below, is necessary to adjust the transmitter sensitivity for accurate measurements of oxygen contents in a sample gas. As a rule of thumb, zero calibration should be carried out after span calibration.
Zero Calibration
Despite the absolute zero inherent in the electrochemical oxygen sensors, the reality is that analyzers may display an oxygen reading even when sampling a zero gas (oxygen free gas) due to:
1. Contamination or questionable quality of the zero gas
2. Minor leakage in the sample line connections
3. Residual oxygen dissolved in the sensor’s electrolyte
4. Tolerances of the electronic components
The maximum “Zero Offset” of every analyzer is checked prior to shipment. However, due to the fact that the factory sample system conditions differ from that of the user, no ZERO OFFSET adjustment is made at the factory
Span Calibration
Involves periodically, see Intervals section below, checking and/or adjusting the electronics to the sensor’ s signal output at a given oxygen standard. The frequency of calibration varies with the application, e.g., the degree of accuracy required by the application and the quality assurance protocol of the user. However, the interval between span calibrations should not exceed three (3) months.
Note: Regardless of the oxygen concentration of the standard used, the span calibration process takes approximately 10-15 minutes. However, the time required to bring a PPM analyzer back on-line after span calibration can vary, see Online Recovery Time below.
Considerations
When it comes to the calibration of oxygen analyzers utilizing an electrochemical oxygen sensor, circumstances vary widely from the ideal conditions that exist at the factory to a variety of differing circumstances users encounter in the field. The following describes the most common factors and reasons that influence the calibration procedures.
All electrochemical sensor based analyzers require periodic calibr ation, e.g. weekly intervals to a 3 month maximum, to ensure accuracy and ascertain the integrity of the sensor
For optimum accuracy, calibrate the analyzer at or close to the temperature and pressure of the sample gas The priority users place on getting or keeping an analyzer online is “the” most significant factor involved in
calibration and troubleshooting issues. The time it takes an analyzer to come down to a specific level after exposure to high O2 concentrations or air is significantly different if a sensor is being installed than if the sensor had been in-service at low oxygen levels for more than 1 week.
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Sensor Calibration at
Install
PPM Fuel Cell
The above times assume the introduction of a zero gas (low level of oxygen in nitrogen) after span calibration.
For optimum accuracy, the O2 concentration of a span gas should be approximate 50-90% of the full scale range of analysis or one range above the analysis range, e.g. 20.9% O2 on the 0-25% range. Co nversely, if the recommended span gas is not available and air calibration is not an option, a spa n gas of the same full scale range and near the anticipated analysis level (approximatel y 30-50% of full scale) is acceptable with the understanding that the accuracy will suffer slightly.
Use of span gas near 30% of the full scale range of measurements, at the higher end of the range has the effect of “expanding the error” as illustrated by Graph A in Example 1 in the Accuracy section above.
Prematurely initiating the SPAN CALIBRATION function (before the analyzer reading ha s stabilized) can result in erroneous readings as follows:
When purging an analyzer to lower ranges and calibrating with a spa n gas: If the oxygen reading reaches less than 2% of the intended calibration range, enter the value of the span gas. If the oxygen reading is greater than 2% of the calibration range, add the O2 reading to the value of the span gas (the impact of the offset on accuracy is minor but the addition allows the oxygen sensor to continue to purge down and avoid negative readings after calibration.
When installing a new oxygen sensor and calibrating with air, allow 2-3 minutes for the sensor to equilibrate in ambient air from storage packaging. Failure to do so can introduce error in calibration.
Air to .1% < 1 min
Air to 100 PPM < 5 min
Air to < 10PPM < 60 min
In-service Calibration
Similar
Less than 45 min
Zero Calibration
Typical offset from a PPM analyzer is less than 0.5 PPM. Therefore, for most applications, a Zero calibration is not required. However, ZERO calibration feature has been provided to allow the user to precisel y measure oxygen concentration at the very low levels (less than 0.5 PPM). As described below, accomplishing either objective places a degree of responsibility on the user.
Determining the true offset requires the user to wait (see Online Recovery Time section) until the analyzer reading is no longer trending downward (best evidenced by a constant horizontal trend on an external recording device.
The zero offset adjustments is limited to 50% of the most sensitive range of the analyzer. At factory, analyzer is QC tested to confirm that the maximum offset is less than 50% of the most sensitive range available. Should you observe a zero offset more than 50% of the lowest range, check sample system for any possible leaks, integrity of the zero gas and assure that the analyzer has been given enough time to stabilize on zero gas before initiating the ZERO CALIBRATION.
Caution: If adequate time is not allowed for the analyzer to establish the true baseline and a ZERO calibration is performed, the analyzer will in all probability display a negative reading in the sample mode after a certain period of time. If a negative reading is seen, perform ZERO calibration again.
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Span Gas vs. Air Calibration
The analyzer can be calibrated by using ambient air (20.9% O2 ) or a certified span gas. The only advantage of using a certified span gas for calibration is the fast recovery time to low PPM level after calibration. For example, if the analyzer is calibrated by using 8 PPM span gas, the analyzer will recover to within 0.1 PPM of the original reading within five minutes. On the other hand, if the analyzer is calibrated with ambient air, it may take 1-2 hours for the reading to get below 0.5 PPM
Zero Calibration Procedure
Zero calibration should be carried out after the span calibration has been performed. Normally, zero calibrations are performed when a new sensor is installed or changes are made in the sample system connections.
Before performing a ZERO calibration, it is highly recommended to perform a factory default zero. This will eliminate previous zero offset adjustment that might have been made. With factory default setting, if the zero offset does not exceed 50% of the lowest range, this indicates that the integrity of the sensor, the analyzer sample system and the sample line bringing in the sample gas is maintained.
Access the MAIN MENU by pressing the MENU key. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION. Press the ENTER key to select the highlighted menu option. The following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS BYPASS ALARMS
Advance the reverse shade cursor using the ARROW keys to highlight ZERO CALIBRATE. Press the ENTER key to select the highlighted menu option. The following displays appear:
ZERO CALIBRATION ENTER TO CALIBRATE MENUE TO ABORT
Press the ENTER key to calibrate or MENU key to abort and return to SAMPLING mode. Allow approximately 60 seconds for the calibration process while the microprocessor determines whether
the signal output or reading has stabilized within 50% of the full scale low range. If the offset is less than 50% of the lowest range, by pressing ENTER, message PASSED CALIBRATION will appear and return to the Sample mode. On the other hand, if the offset is above 50%, pressing ENTER, message FAILED CALIBRATION will appear and the micro will return to Sample mode without completing the Zero calibration.
>>>
CALIBRATION
SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN DEFAULT ZERO OUTPUT SPAN OUTPUT ZERO
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Both the Zero Calibrate and Span Calibrate functions result in the following displays:
PASSED CALIBRATION
OR
FAILED CALIBRATION
Default Zero
The feature will eliminate any previous zero calibration adjust ment and display the actual signal output of the sensor with the zero/sample gas. For example, assuming a zero gas is introduced, the display above 0.0 0 PPM will reflect an actual zero offset. This feature allows the user to ensure that the accumulative zero offset never exceeds 50% of the lowest range limit. To perform Default Zero,
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.
3. Press the ENTER key to select the highlighted menu option.
The following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS BYPASS ALARMS
>>>
CALIBRATION
SPAN CALIBRATE ZERO CALIBRATE DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN OUTPUT ZERO
4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT ZERO.
5. Press the ENTER key to select the highlighted menu option.
The following display appears and after 3 seconds the system returns to the SAMPLING mode:
FACTORY DEFAULTS SET
3.3 PPM
AUTO SAMPLING 10 PPM RANGE
76 F 100 KPA
Analog Output with Zero O2
In rare instances the 4-20mA signal output may not agree with the reading displayed on the LCD. This feature enables the user to adjust the 4mA signal output when the LCD displays 00.00.
Note Adjust the 20mA signal output with the OUTPUT SPAN option described below. To adjust the 4 mA signal
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.
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3. Press the ENTER key to select the highlighted menu option and the following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS BYPASS ALARMS
>>>
CALIBRATION
SPAN CALIBRATE ZERO CALIBRATE DEFAULT SPAN DEFAULT ZERO OUTPUT SPAN
OUTPUT ZERO
4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT ZERO.
5. Press the ENTER key to select the highlighted menu option and the following display appears:
100.0 OUTPUT ZERO OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
The default setting of 100 illustrates no adjustment to the analog output signal. Compute the adjustme nt value as described in Appendix B or consult the factory. The true adjustment value must be determined empirically by trial and error. Adjust the initial value to above 100 to increa se the analog signal value or decrease it below 100 to decrease the analog signal.
090.0
OUTPUT ZERO OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
6. Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to the desired digit of the OUTPUT ZERO OFFSET value.
7. Press the ARROW keys to enter the OUTPUT ZERO OFFSET value.
8. Repeat the OUTPUT ZERO OFFSET routine until the output is 4 mA .
Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key. After adjustment, the system returns to the SAMPLING mode.
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Span Calibration Procedure
This procedure assumes a span gas under positive pressure and is recommended for a transmitter without an optional sampling pump, which if installed downstream of the sensor should be placed in the OFF position and disconnected so the vent is not restricted during calibration.
To assure an accurate calibration, the temperature and pressure of the span gas must closely match with the sample gas.
For calibration purposes, use of “AUTO SAMPLE” mode is recommended. To begin span calibration
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight AUTO SAMPLE.
3. Press the ENTER key to select the highlighted menu option.
The following displays appear:
MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE CALIBRATION CONFIG ALARMS BYPASS ALARMS
76 F 100 KP
0.3 PPM
AUTO SAMPLING 0-10 PPM RANGE
4. Return to the MAIN MENU by pressing the MENU key.
5. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.
6. Press the ENTER key to select the highlighted menu option.
7. Repeat to select SPAN CALIBRATE
The following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS BYPASS ALARMS
>>>
8. After selecting the SPAN CALIBRATION, enter appropriate span gas value.
9. Advance the reverse shade cursor using the ARROW keys to highlight the desired GAS CONCENTRATION.
10. Press the ENTER key to select the highlighted menu option.
GAS CONCENTRATION
PERCENT
PPM
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CALIBRATION
SPAN CALIBRATE
ZERO CALIBRATE DEFAULT SPAN DEFAULT ZERO OUTPUT SPAN OUTPUT ZERO
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The following displays appear:
000.00 % PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
11. Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to the desired digit of the alarm value.
12. Repeat until the complete span value has been entered.
13. Press the ENTER key to accept SPAN CALIBRATION. After successful calibration, the analyzer will display a message “PASSED CALIBRATION” and return to the Sample mode.
NOTE: The transmitter is allowed to accept calibration only when O2 reading is within 50% of the span gas value. If the O2 reading is outside of this limit, by pressing ENTER to accept calibration will result in “FAILED CALIBRATION” and the analyzer will return to the Sample mode without completing Span calibration.
PASSED CALIBRATION
>>>
OR
0.55%
SPAN CLAIBRATION ENTER TO CALIBRATE MENU TO ABORT
FAILED CALIBRATION
If the calibration is unsuccessful, return to the SAMPLING mode with span gas flowing through the transmitter, make sure the reading stabilizes, reaches within 30-50% (see below) of the span gas value (after factory default span setting) and repeat the calibration before concluding the equipment is defective.
Before disconnecting the span gas line and connecting the sample gas line (if the analyzer is not equipped with a SPAN/SAMPLE vale option), flow the sample gas for 1-2 minutes to purge the air inside the sample line, then disconnect the span gas line and replace it with the sample gas line.
Default Span
With factory default span, previous calibration data stored in the memory is removed and the sensitivity of the analyzer is reset to the value based on the average output of the oxygen sensor at a specific oxygen concentration. For example, with factory default settings, when a span gas is introduced, the micro­processor will display oxygen reading within 30-50% of the span gas value, indicating that the sensor output is within the specified limits. This feature allows the user to check the sensor’s signal output without removing it from the sensor housing. To begin Factory Default span,
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.
3. Press the ENTER key to select the highlighted menu option.
The following display appears:
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MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS BYPASS ALARMS
>>>
CALIBRATION
SPAN CALIBRATE ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO OUTPUT SPAN OUTPUT ZERO
4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT SPAN.
5. Press the ENTER key to select the highlighted menu option.
The following displays appear and after 3 seconds the system returns to the SAMPLING mode:
FACTORY DEFAULTS SET
3.1 PPM
76 F 100 KPA
AUTO SAMPLING
10 PPM Range
4-20 mA Output Adjustment
In rare instances the 4-20mA signal output may not agree to the reading displayed by the LCD. This feature enables the user to adjust the 20mA signal output should the LCD display not agree.
Note: Adjust the 4mA signal output with the OUTPUT ZERO option described above. To begin 20 mA signal adjustment
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.
3. Press the ENTER key to select the highlighted menu option.
The following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS BYPASS ALARMS
4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT SPAN.
5. Press the ENTER key to select the highlighted menu option.
The following display appears
>>>
CALIBRATION
SPAN CALIBRATE ZERO CALIBRATE DEFAULT SPAN DEFAULT ZERO
OUTPUT SPAN
OUTPUT ZERO
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100.0 OUTPUT SPAN OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
The default setting of 100 illustrates no adjustment to the analog output signal. Compute the adjustme nt value as described in Appendix B or consult the factory. The true adjustment value must be determined empirically by trial and error. Adjust the initial value to above 100 to increase the 20 mA analog signal value or decrease it below 100 to decrease the 20 mA analog signal.
6. Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to the desired digit of the OUTPUT SPAN OFFSET value.
7. Press the ARROW keys to enter the OUTPUT SPAN OFFSET value.
8. Repeat above steps until the complete OUTPUT SPAN OFFSET value has been entered.
9. Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.
The system returns to the SAMPLING mode.
Setting Alarms
The analyzer is equipped with two programmable alarm relays. The two alarms set points are user adjustable and can be set either as LOW/HIGH, LOW/LOW or HIGH/HIGH.
Alarm Delay
A user programmable alarm delay function is available. This feature allows the user to ignore the alarm should a sudden short duration spike in the oxygen reading occurs.
Alarm Bypass
The alarms bypass feature allows the user to bypass the alarm during trouble shooting/repair or test runs. However, once the alarm bypass is selected, alarm will remain disabled even if the oxygen reading is over/under the alarm set point. The alarm will re-arm itself only after the fault condition has been reverted.
The alarms are automatically disabled during SPAN/ZERO calibration. The alarm relays are rated at 5A @ 250V. CAUTION; When using these relays, do not exceed the recommended rating.
Power Failure Alarm
A relay contact that is normally energized (normally open) during op eration, is closed if the power to the analyzer is turned OFF.
The relay is rated at 5A @ 250V.
CAUTION: When using this relay, do not exceed the recommended rating.
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Sampling
GPR-1500-A Oxygen Transmitter requires a positive pressure to flow the sample gas across the sensor to measure the oxygen concentration in a sample gas. If a positive pressure sample not available, see Pressure & Flow section.
Procedure
Following calibration, the transmitter returns to the SAMPLE mode. From the Sample Mode,
1. Select the desired sampling mode - auto or if manual, the range that provides maximum resolution – as described above.
2. Use metal tubing to transport the sample gas to the transmitter. The main consideration is to eliminate air leaks which can affect oxygen measurements above or below the 20.9% oxygen concentration in ambient air - ensure the sample gas tubing connections fit tightly into the sample input port.
3. For sample gases under positive pressure, the user must provide a means of controlling the inlet pressure between 5-30 psig and the flow of the sample gas between 1-5 SCFH, a flow rate of 1-2 SCHF is recommended
4. For sample gases under atmospheric or slightly negative pressure, an optional sampling pump is recommended to push the sample the sensor housing. Generally, when using a pump, no pressure regulation or flow control device is involved. However, a flow meter upstream of analyzer is recommended to ensure that the sample flow is adequate.
5. Assure the sample is adequately vented for optimum response and recovery – and safety.
6. Allow the oxygen reading to stabilize for approximately 10 minutes at each sample point.
Note: To avoid erroneous oxygen readings and damage to the sensor, 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).
7. Assure there are no restrictions in the sample or vent lines
8. Avoid drawing a vacuum that exceeds 14” of water column pressure – unless don e gradually
9. Avoid excessive flow rates above 5 SCFH which may generate backpressure on the sensor.
10. Avoid sudden releases of backpressure that can severely damage the sensor.
11. Avoid the collection of particulates, liquids or condensation on the sensor that could block t he diffusion of oxygen into the sensor.
Standby
The transmitter has no special storage requirements. The sensor should remain inside of the sensor housing and connected to the electronics during storage
periods. Before turning the sample gas OFF, ensure that sample/bypass valve (if analyzer equipped) is at the BYPASS position. This will keep the sensor isolated from ambient air and would be ready to use again when required with very short down time. If the transmitter is not equipped with a sample bypass and a shut off valve, allow a very low flow (less than 0.1 SCFH) of a low PPM gas flowing through the sensor. This will ensure that air would not diffuse into the sensor housing and the sensor will remain purged and ready for a sample gas analysis.
NOTE: Under isolated conditions, some oxygen will diffuse into the sample system/sensor housing and the sensor out will slowly climb up but after 2-3 hours, it will reach a Plato, generally less than 400 PPM
Store the transmitter with the power OFF at a safe location and away from a direct heating source. If storing for an extended period of time, protect the analyzer from dust, heat and moisture.
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6. Maintenance
Generally, cleaning the electrical contacts inside of the upper section of the sensor housing or replacing filter element of the coalescing filter is the extent of the maintenance requirements of this transmitter.
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.
7. Spare Parts
Recommended spare parts for the GPR-1800 IS Oxygen Transmitter:
Item No. Description
GPR-12-333 Oxygen Sensor, for measuring O2 in inert gases XLT-12-333 Oxygen Sensor, for measuring O2 in gases
containing CO2
Other spare parts:
Item No. Description
B-2762-A-2-14 Sensor Housing Upper Section MTR-1011 Meter Digital Panel LCD Backlight A-1161-1 PCB Assembly Main / Display A-1166-IS-1 PCB Assembly Power Supply
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8. Troubleshooting
Symptom Possible Cause Recommended Action
Slow recovery or
High O after installing or replacing sensor
High O2 reading Sampling
reading
2
At installation, defective sensor
Air leak in sample system connection(s)
Abnormality in zero gas Damaged in service -
prolonged exposure to air, electrolyte leak
Sensor nearing end of life
Transmitter calibrated before sensor stabilized caused by:
1) Prolonged exposure to ambient air, worse if sensor was un-shorted
2) Air leak in sample system connection(s)
3) Abnormality in zero gas
Flow rate exceeds limits Pressurized sensor Improper sensor selection
Replace sensor if recovery unacceptable
reading fails to reach 10% of lowest
or O
2
range Leak test the entire sample system: Vary
the flow rate, if the O inversely with the change in flow rate indicates an air leak - correct source of leak
Qualify zero gas (using portable transmitter)
Replace sensor
Replace sensor
Allow O making the span/calibration adjustment
Continue purge with zero gas
Leak test the entire sample system (above)
Qualify zero gas (using portable transmitter)
Correct pressure and flow rate Remove restriction on vent line Replace GPR/PSR sensor with XLT
sensor when CO present
reading to stabilize before
2
reading changes
2
or acid gases are
2
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Symptom Possible Cause Recommended Action
Response time slow
O2 reading doesn’t agree to expected
values
O
2
Erratic O
reading
2
or
reading
No O
2
Erratic O
reading
2
or Negative O
reading
2
36
Air leak, dead legs, distance of sample line, low flow rate, volume of optional filters and scrubbers
Pressure and temperature of the sample is different than span gas
Abnormality in gas
Change in sample pressure
Dirty electrical contacts in upper section of sensor housing
Corroded solder joints on sensor PCB from corrosive sample or electrolyte leakage from sensor
Corroded spring loaded contact in upper section of sensor housing from liquid in sample or electrolyte leakage from sensor
Liquid covering sensing area
Improper sensor selection
Presence of interference gases
Unauthorized maintenance Sensor nearing end of life
Pressurizing the sensor by flowing gas to the sensor with the vent restricted or SHUT OFF valve closed and
Leak test (above), reduce dead volume or increase flow rate
Calibrate the transmitter (calibrate at pressure and temperature of sample)
Qualify the gas (use a portable analyzer as a second check)
Calibrate the transmitter (calibrate at pressure and temperature of sample)
Clean contacts with alcohol (minimize exposure time of MS sensor to ambient air to extent possible)
Replace sensor and return sensor to the factory for warranty determination
Upper section of sensor housing: Clean contacts with water, wipe contacts with clean paper towel and flush system and sensor housing with dry gas
Sensor: Replace if leaking and return it to the factory for warranty determination
Wipe with lint free towel or flow dry sample or zero gas for 2-3 hours to flush out condensation
Consult factory for recommendation.
Replace sensor and install scrubber
Consult factory. Replace sensor
Zero the transmitter. If not successful replace the sensor
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or
reading
No O
2
accompanied by electrolyte leakage
suddenly removing the restriction draws a vacuum on the sensor
or partially opened valves
upstream of the transmitter when using a pump downstream of the transmitter to draw sample from a process at atmospheric pressure or under a slight vacuum. Placing a vacuum on the sensor in excess 10” of water column is strongly discouraged.
A premature adjustment of the ZERO OFFSET potentiometer is a common problem
Avoid drawing a vacuum on the sensor, a pressurized sensor may not leak but still produce negative readings.
From MAIN MENU select DEFAULT ZERO
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9. Warranty
The design and manufacture of GPR Series oxygen transmitters/analyzers, monitors and oxygen sensors are performed under a certified Quality Assurance System that conforms to established standards and incorporates state of the art materials and components for superior performance and minimal cost of ownership. Prior to shipment every analyzer is thoroughly tested by the manufacturer and documented in the form of a Quality Control Certification that is included in the Owner’s Manual accompanying every analyzer. When operated and maintained in accordance with the Owner’s Manu al, the units will provide many years of reliable service.
Coverage
Under normal operating conditions, the monitor, analyzers and sensor are warranted to be free of defects in materials and workmanship for the period specified in accordance with the most recent published specifications, said period begins with the date of shipment by the manufacturer. The manufacturer information and serial number of this analyzer are located on the rear of the analyzer. Advanced Instruments Inc. reserves the right in its sole discretion to invalidate this warranty if the serial number does not appear on the analyzer.
If your Advanced Instruments Inc. monitor, analyzer and/or oxygen sensor is determined to be defective with respect to material and/or workmanship, we will repair it or, at our option, replace it at no charge to you. If we choose to repair your purchase, we may use new or reconditioned replacement parts. If we choose to replace your Advanced Instruments Inc. analyzer, we may replace it with a new or reconditioned one of the same or upgraded design. This warranty applies to all monitors, analyzers and sensors purchased worldwide. It is the only one we will give and it sets forth all our responsibilities. There are no other express warranties. This warranty is limited to the first customer who submits a claim for a given serial number and/or the above warranty period. Under no circumstances will the warranty extend to more than one customer or beyond the warranty period.
Limitations
Advanced Instruments Inc. will not pay for: loss of time; inconvenience; loss of use of your Advanced Instruments Inc. analyzer or property damage caused by your Advanced Instruments Inc. analyzer or its failure to work; any special, incidental or consequential damages; or any d amag e resulting from alterations, misuse or abuse; lack of proper maintenance; unauthorized repair or modification of the analyzer; affixing of any attachment not provided with the analyzer or other failure to follo w the O wner’s Manual. Some state s and provinces do not allow limitations on how an implied warranty lasts or the exclusion of incidental or consequential damages, these exclusions may not apply.
Exclusions
This warranty does not cover installation; defects resulting from accidents; damage while in transit to our service location; damage resulting from alterations, misuse or abuse; lack of proper maintenance; unauthorized repair or modification of the analyzer; affixing of any label or attachment not provid ed with the analyzer; fire, flood, or acts of God; or other failure to follow the Owner’s Manual.
Service
Call Advanced Instruments Inc. at 909-392-6900 (or e-mail info@aii1.com) between 7:30 AM and 5:00 PM Pacific Time Monday thru Thursday or 8:00 AM to 12:00 pm on Friday. Trained technicians will assist you in diagnosing the problem and arrange to supply you with the required parts. You may obtain warranty service by returning you analyzer, postage prepaid to:
Advanced Instruments Inc. 2855 Metropolitan Place Pomona, Ca 91767 USA
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Be sure to pack the analyzer securely. Include your name, address, telephone number, and a description of the operating problem. After repairing or, at our option, replacing your Advanced Instruments Inc. analyzer, we will ship it to you at no cost for parts and labor.
10. MSDS – Material Safety Data Sheet
Product Identification
Product Name Oxygen Sensor Series - PSR, GPR, AII, XLT Synonyms Electrochemical Sensor, Galvanic Fuel Cell Manufacturer Advanced Instruments Inc., 2855 Metropolitan Place, Pomona, CA 91767 USA Emergency Phone Number 909-392-6900 Preparation / Revision Date January 1, 1995 Notes Oxygen sensors are sealed, contain protective coverings and in normal conditions do not
Specific Generic Ingredients
Carcinogens at levels > 0.1% None Others at levels > 1.0% Potassium Hydroxide or Acetic Acid, Lead CAS Number Potassium Hydroxide = KOH 1310-58-3 or Acetic Acid = 64-19-7, Lead = Pb 7439-92-1 Chemical (Synonym) and
Family
General Requirements
Use Potassium Hydroxide or Acetic Acid - electrolyte, Lead - anode Handling Rubber or latex gloves, safety glasses Storage Indefinitely
Physical Properties
Boiling Point Range Melting Point Range Freezing Point Molecular Weight KOH = 56 or Acetic Acid – NA, Lead = 207 Specific Gravity Vapor Pressure Vapor Density KOH – NA or Acetic Acid = 2.07 pH KOH > 14 or Acetic Acid = 2-3 Solubility in H % Volatiles by Volume None Evaporation Rate Similar to water Appearance and Odor Aqueous solutions: KOH = Colorless, odorless or Acetic Acid = Colorless, vinegar-like
O Complete
2
Fire and Explosion Data
Flash and Fire Points Not applicable
39
present a health hazard. Information applies to electrolyte unless otherwise noted.
Potassium Hydroxide (KOH) – Base or Acetic Acid (CH
KOH = 100 to 115° C or Acetic Acid = 100 to 117° C KOH -10 to 0° C or Acetic Acid – NA, Lead 327° C KOH = -40 to -10° C or Acetic Acid = -40 to -10° C
KOH = 1.09 @ 20° C, Acetic Acid = 1.05 @ 20° C KOH = NA or Acetic Acid = 11.4 @ 20° C
odor
H) – Acid, Lead (Pb) – Metal
3CO2
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Flammable Limits Not flammable Extinguishing Method Not applicable Special Fire Fighting
Procedures Unusual Fire and Explosion
Hazards
Not applicable
Not applicable
Reactivity Data
Stability Stable Conditions Contributing to
Instability Incompatibility KOH = Avoid contact with strong acids or Acetic Acid = Avoid contact with strong bases Hazardous Decomposition
Products Conditions to Avoid KOH = None or Acetic Acid = Heat
None
KOH = None or Acetic Acid = Emits toxic fumes when heated
Spill or Leak
Steps if material is released Sensor is packaged in a sealed plastic bag, check the sensor inside for electrolyte
Disposal In accordance with federal, state and local regulations.
leakage. If the sensor leaks inside the plastic bag or inside an analyzer sensor housing do not remove it without rubber or latex gloves and safety glasses and a source of water. Flush or wipe all surfaces repeatedly with water or wet paper towel (fresh each time).
Health Hazard Information
Primary Route(s) of Entry Ingestion, eye and skin contact Exposure Limits Potassium Hydroxide - ACGIH TLV 2 mg/cubic meter or Acetic Acid - ACGIH TLV /
Ingestion Electrolyte could be harmful or fatal if swallowed. KOH = Oral LD50 (RAT) = 2433 mg/kg
Eye Electrolyte is corrosive and eye contact could result in permanent loss of vision. Skin Electrolyte is corrosive and skin contact could result in a chemical burn. Inhalation Liquid inhalation is unlikely. Symptoms Eye contact - burning sensation. Skin contact - soapy slick feeling. Medical Conditions Aggravated None Carcinogenic Reference Data KOH and Acetic Acid = NTP Annual Report on Carcinogens - not listed; LARC
Other Lead is listed as a chemical known to the State of California to cause birth defects or
OSHA PEL 10 % (TWA), Lead - OSHA PEL .05 mg/cubic meter
or Acetic Acid = Oral LD50 (RAT) = 6620 mg/kg
Monographs - not listed; OSHA - not listed
other reproductive harm.
Special Protection Information
Ventilation Requirements None Eye Safety glasses Hand Rubber or latex gloves Respirator Type Not applicable Other Special Protection None
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Special Precautions
Precautions Do not remove the sensor’s protective Teflon and PCB coverings. Do not
probe the sensor with sharp objects. Wash hands thoroughly after handling. Avoid contact with eyes, skin and clothing.
Empty sensor body may contain hazardous residue.
Transportation Not applicable
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Appendix A
Electrical connections require an approved explosion proof sealing fitting and packing around wires and cables (for incoming power for the analyzer electronics and 4-20mA signal output) coming into and out of the explosion proof enclosure that houses the power supply/signal output PCB.
Full compliance with hazardous area electrical code requires the user to supply glands, fittings and/or conduit commensurate with the level of protection or classification desired. To maintain the ATEX certification of this unit, the user must install ATEX approved components according to ATEX directives. To meet the NEC standard for use in Class 1, Division 1, Group C, D hazardous areas, the user must install the appropriate components according to NEC standards.
Note: The following instruction is supplied from information and data supplied by a reputable enclosure
manufacturer which we believe is reliable and is given in good faith. Since the methods of applicati on and conditions under which our products are put to use are beyond our control, we are not able to guarante e the application and/or use of same. The user assumes all risks and liability in connection with the application and use of our products.
Directions for use of Explosion Proof Packing Fiber ( non-asbestos )
For use as packing at the hub of sealing fittings, tamp packing fiber between and around conductors where they enter fitting to prevent leakage of the liquid cement. Leave enough space in the fitting for length equivalent to the inside diameter of the conduit but, not less then 5/8”.
Caution: Avoid getting in eyes or breathing dust Use barrier cream, gloves and long sleeve shirts if dust or fiber is irritating. Prolonged contact may cause lung, eye or skin irritation.
Directions for use Explosion Proof Sealing Cement: Tamp packing fiber between and around conductors where they
enter the sealing fitting to prevent leakage of liquid cement. Make sure conductors are not in contact with each other or with the wall of fitting. Leave space in the fitting for a sealing length equivalent to the thread size of the conduit seal but not less than 5/8”
Fill the marked shipping container with clean cold water to the “water line” [35 ml to be precise].
Caution: Do not exceed the required amount of water.
Gradually pour cement from the plastic bag into the water and stir thoroughly for proper mixture. Fill fitting completely within five (5) minutes after mixing, then tamp with blunt stick to expel any air bubbles. Close up any opening in the fitting to insure integrity of the seal. Fittings requiring more than 10 oz. of cement must be filled from a single mixture of cement and water. DO NOT POUR IN STAGES. hours to cure. Water-mix sealing compound should not be poured or installed at temperature below 40F (4C). Maintain temperature at or above 40F for at least 72 hours after pouring. CSA certified when used with any CSA certified sealing fitting. Adaco No. 1 sealing cement must be used as a part of any Adalet UL listed fitting.
Caution: At least five threads must engage on all fill plugs. Prolonged breathing or ingestion may cause internal obstruction, seek medical care.
Allow cement at least 72
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Do not get into eyes or on skin – if cement touches eyes or skin, flush with water for 15 minutes. Large amounts on skin when hardening may cause skin burn. Use adequate ventilation.
To reorder sealing cement kit, specify P/N ENCL-1071-KIT
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Appendix B
Matching - LCD Display with 4-20mA Output
In rare instances the 4-20mA signal output may not agree with the reading displayed on the LCD. The Output Zero and Output Span features enable the user to adjust the 4mA and 20 mA signal output matching with the reading displayed by the LCD.
For optimum accuracy make two separate adjustments as follows:
1. OUTPUT ZERO feature: To adjust the 4mA signal output and requires zero gas.
2. OUTPUT SPAN feature: To adjust the 20mA signal output and requires span gas near full range.
Note: In the field or in the absence of the preferred gases, use the OUTPUT SPAN feature and adjust the 20mA signal output using the span gas available.
Procedure – regardless of type of adjustment:
1. When you select OUTPUT ZERO OR OUTPUT SPAN, the microprocessor defaults to 100% to start.
2. The “actual” 4-20mA signal output will be adjusted to the “theoretical” value of the LCD display.
3. Adjustment general rule:
a) If the actual 4-20mA value < the theoretical LCD value, the adjustment value will be > 100%. b) If the actual 4-20mA value > the theoretical LCD value, the adjustment value will be < 100%.
4. Convert the “actual” reading of the LCD display to the “theoretical” 4-20mA as follows:
a) Divide the “actual” (% or percent) LCD reading by the value of the span gas available. b) Multiply 16mA (20mA – 4mA) times the “result of a.” c) Add 4mA plus the “result of b.” to obtain the “theoretical” 4-20mA signal output value.
5. Adjustment value: Divide the theoretical by the actual 4-20mA values and multiply by 100.
6. Enter the adjustment value via OUTPUT ZERO or OUTPUT SPAN routines described below.
Example: Analyzer reading is 60 % oxygen (100 % range) on 84 % span gas, 4-20mA signal output at
PLC is 24mA
Solution: a) Use OUTPUT SPAN feature to make the adjustment.
b) Adjustment will be < 100% (default value of OUTPUT SPAN feature). c) 13.6mA is the “theoretical” 4-20mA converted from the “actual” reading of the LCD. 60 % divided by 84 % = 0.71 or 71% 16mA multiplied by 0.71 = 11.36mA 4mA plus 11.36mA = 15.36mA “theoretical” 4-20mA signal output value d) 15.36mA divided by 24mA the “actual” 4-20mA value = 64.0 adjustment value e) Enter 64.0 via OUTPUT SPAN procedure below.
Adjust 4 mA with Zero O2
Access the MAIN MENU by pressing the MENU key.
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Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION. Press the ENTER key to select the highlighted menu option. The following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
>>>
CALIBRATION
SPAN CALIBRATE ZERO CALIBRATE DEFAULT SPAN DEFAULT ZERO OUTPUT SPAN
OUTPUT ZERO
Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT ZERO. Press the ENTER key to select the highlighted menu option. The following display appears:
100.0 OUTPUT ZERO OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
Enter the calculated adjustment value. Note: Once the initial adjustment is made and checked at the PLC
it may be necessary to fine tune the initial adjustment by repeating. Any additional percent error must be added or subtracted from the initial adjustment value
000.0 OUTPUT ZERO OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to the desired digit of the adjustment OUTPUT ZERO OFFSET value.
Press the ARROW keys to enter each the numerical value of each digit of the adjustment OUTPUT ZERO OFFSET value.
Repeat until the complete OUTPUT ZERO OFFSET value has been entered.
Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key. The system returns to the SAMPLING mode.
Adjust 20 mA at known O2
Access the MAIN MENU by pressing the MENU key.
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Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION. Press the ENTER key to select the highlighted menu option. The following displays appear:
MAIN MENU
AUTO SAMPLE MANUAL SAMPLE
CALIBRATION
>>>
CALIBRATION
SPAN CALIBRATE ZERO CALIBRATE DEFAULT SPAN DEFAULT ZERO
OUTPUT SPAN
OUTPUT ZERO
Advance the reverse shade cursor using the ARROW keys to highlight OUTPUT SPAN. Press the ENTER key to select the highlighted menu option. The following display appears:
100.0 OUTPUT SPAN OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
Enter the calculated adjustment value, refer to example described above. Note: Once the initial adjustment is made and checked at the PLC it may be necessary to fine tune the initial
adjustment by repeating. Any additional percent error must be added or subtracted from the initial adjustment value
064.0 OUTPUT SPAN OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to the desired digit of the adjustment OUTPUT SPAN OFFSET value.
Press the ARROW keys to enter the numerical value of each digit of the OUTPUT SPAN OFFSET value. Repeat until the complete OUTPUT SPAN OFFSET value has been entered.
Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key. The system returns to the SAMPLING mode.
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Appendix G
Maintenance – H2S Scrubber
Servicing any of the H2S scrubbers will depend on several factors as illustrated in Appendix F and include: the (average) H2S concentration, volume of scrubber media and flow rate through the scrubber (often times maximizing the service life means longer system response time) see Appendix F.
Required equipment:
1. 2x 7/16” open end wrenches
2. 1x 9/16” open end wrench
3. 1x 1” open end or adjustable wrench
Procedure:
Separate the top connection to the scrubber using a 7/16” and the 9/16” open end wrenches on the two top nuts.
Hold the second nut with the 9/16” open end wrench. With one of the 7/16” open end wrenches turn the top nut counter clockwise until the fitting disengages. Separate the bottom connection to the scrubber using both 7/16” open end wrenches. Hold the nut at the bottom of the scrubber with a 7/16” open end wrench. With the other 7/16” open end wrench turn the nut below counter clockwise until the fitting disengages. Carefully, remove the stainless tubing from the top and bottom of the scrubber. Carefully pull the scrubber from its mounting clip which is attached to the back panel. Once the scrubber is free, hold the scrubber with one hand and using the 1” open end or adjustable wrench
with the other hand, turn the 1” nut counter clockwise and remove the 1” nut from the scrubber. There is no need to remove the 7/16” fitting at the bottom of the scrubber. With the 1” nut removed, empty the spent media through the opening. Fill the scrubber with fresh media (should be rich purple in color). Reverse the above steps to re-assemble and install the scrubber.
Maintenance – Coalescing Filter
Servicing the coalescing filter (P/N FLTR-1002-2) depends on the cleanliness and moisture content of the sample and maintenance intervals.
Required equipment:
Channel locks Damp rag Lubricant (a thin coat applied to the o-ring after cleaning helps ensure a tight seal and extend o-ring life)
Procedure:
Unscrew the clear polycarbonate bowl by turning it counter clockwise. Note: It is probably stuck tight – use a damp rag to grip if removing by hand or to prevent damage to the
bowl if using the channel locks. The bowl seals to the head section with an o-ring, do not lose the o-ring.
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The filter element screws into the head section, carefully turn it counter clockwise and remove it from the head.
Using the damp cloth, clean the inside of the bowl and the o-ring before reassembling – apply a very thin coat of lubricant to the o-ring.
Reverse the above steps to re-assemble the filter.
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