Analytical Industries GPR-18 MS Explosion Proof Oxygen Analyzers User Manual

June 1, 2024
Analytical Industries

Analytical Industries GPR-18 MS Explosion Proof Oxygen Analyzers

Analytical-Industries-GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-
prodcut

Specifications

  • Manufacturer : Analytical Industries Inc.
  • Types: GPR-18 MS, GPR-18, GPR-28
  • Certificate: CML 23ATEX1357X
  • Standards:
    • EN IEC 60079-0:2018
    • EN 60079-1:2014
  • Marking: II 2 G, Ex db IIB or IIB+H2 T6 Gb
  • IECEx Certificate: IECEx CML 23.0122X
  • IEC Standards:
    • IEC 60079-0:2017
    • IEC 60079-1:2014

Product Usage Instructions

Introduction

Your new oxygen analyzer is a precision device designed to measure a wide range of oxygen concentrations. Developed exclusively by Analytical Industries Inc., this analyzer is designed to provide accurate measurements in various gases and gas mixtures.

Essential Information

Ensure to review all symbols, warnings, cautions, and information provided in the manual for safe and proper use of the analyzer.

Installation

  • Unpack and inspect the analyzer carefully.
  • Review available sensors and operating conditions.
  • Mount the analyzer securely following the provided guidelines.
  • Establish electrical and gas connections as per instructions.
  • Install the oxygen sensor properly.

Calibration

  • Understand the calibration process including zero and span calibration.
  • Prepare calibration gas as needed.
  • Perform calibration to ensure accuracy.

Operation

  • Learn about the oxygen display and different display modes.
  • Set up oxygen alarms including power failure and sensor failure alarms.
  • Understand signal outputs and range selection.
  • If applicable, control the optional temperature heater.

Maintenance

  • Regularly replace sensors as needed.
  • Maintain the analyzer enclosure for optimal performance.
Issue No. Description Date Author Initials
01 Original document issued 01/2016 PP
02 Re-brand template

Hazardous area information

| 09/2023| FR
03

3.1

| Updated GPR-28: specifications| 12/2023| FR

NSF

Updated specifications                                 01/2024

Introduction

  • Your new oxygen analyzer is a precision device designed to give you years of measuring a wide range of oxygen concentrations. This analyzer features sensor technology developed exclusively by Analytical Industries Inc.
  • For a discussion of the various analyzer’s performance see section 11 Specifications of this Instructions for Use.
  • The analyzers are designed to measure the oxygen concentration in inert gases, gaseous hydrocarbons, hydrogen, and a variety of gas mixtures. To obtain maximum performance from your new oxygen analyzer, please read and follow the guidelines provided in this Instructions for Use.
  • Every effort has been made to select the most reliable state-of-the-art materials and components; and, to design the analyzer for superior performance and minimal cost of ownership. This analyzer was tested thoroughly by the manufacturer before shipment for best performance.
  • However, these devices do require service from time to time. The warranty included herein plus a staff of trained professional technicians to quickly service your analyzer is your assurance that we stand behind every analyzer sold. The serial number of this analyzer may be found on the side of the analyzer. You should note the serial number in the space provided and retain this Owner’s Manual as a permanent record of your purchase, for future reference and warranty considerations.

Serial Number : ___

  • Analytical Industries Inc. appreciates your business and pledges to make every effort to maintain the highest possible quality standards concerning product design, manufacturing, and service.

Intended Use

  • The Explosion Proof Series of Oxygen Analyzers are designed with an explosion-proof enclosure, flame arrestors, breather device, and actuators and are certified for use in hazardous areas as noted at the right.
  • The equipment shall not have an internal source of release of oxygen or any other oxidizers in concentrations greater than that found in normal air (21%).

GPR-18 MS:

  • 10 PPB to 1000 PPM oxygen contamination in inert gas streams.

GPR-18:

  • 50 PPB to 1% oxygen contamination in inert, hydrocarbon, He, H2, mixed, and acid (CO2) gas streams.

GPR-28:

  • 0.05% to 21% oxygen measurements in inert, hydrocarbons, He, H2, mixed, and acid (CO2) gas streams.

Technical Description Oxygen Analyzer

  • Manufacturer : Analytical Industries Inc.
  • Types: GPR-18 MS, GPR-18, GPR-28
  • ATEX : Certificate: CML 23ATEX1357X
  • Standards: EN IEC 60079-0:2018 EN 60079-1:2014
  • Marking: II 2 G Ex db IIB or IIB+H2 T6 Gb
  • IECEx: Certificate: IECEx CML 23.0122X
  • Standards: IEC 60079-0:2017 IEC 60079-1:2014
  • Marking: Ex db IIB or IIB+H2 T6 Gb
  • Tamb = -20°C to +60°C
  • UKEX: Certificate: CML 23 UKEX1358X
  • Standards: EN IEC 60079-0:2018 EN 60079-1:2014
  • Marking: II 2 G Ex db IIB or IIB+H2 T6 Gb

Flameproof Enclosure

  • Manufacturer: Killark
  • Type: EXB N34 cover, window and three buttons EXB N34 box, 3 holes ½”NPT, 2 holes ¾”NPT
  • ATEX: Certificate: QPS 21ATEX0001U
  • Standards: EN IEC 60079-0: 2018
    • EN 60079-1: 2014
    • EN 60079-31: 2014
    • EN 60529: 1992+A2:2013
  • Marking: II 2G Ex db IIB+H2 Gb II 2D Ex tb IIIC Db IP66 Ta= -50˚C. +70˚C
  • UKEX: Certificate: 3CT UKEX1002U
  • Standards: EN IEC 60079-0: 2018
  • EN 60079-1: 2014
  • EN IEC 60079-31: 2014
  • Marking: II 2G Ex db IIB+H2 Gb II 2D Ex tb IIIC Db IP66 Ta= -50˚C. +70˚C
  • IECEx: Certificate: IECEx QPS 17.0013U
  • Standards: IEC 60079-0:2017 Edition: 7.0
  • IEC 60079-1:2014-06 Edition: 7.0
  • IEC 60079-31:2013 Edition: 2.0
  • Marking: Ex db IIB+H2 T6 Gb Ex tb IIIC Db IP66
  • Tamb = -20°C to +60°C
  • Volume : 13L
    Maximum power dissipated: 93W

Flame Arrestors and Breather

  • Manufacture r: Michell Instruments
  • Type: FA-2-A Flame Arrestors and BR-2-A Breathers
  • ATEX: Certificate: CML 20ATEX1302U
  • Standard: EN IEC 60079 60079-0:2018
    • EN 60079 60079-1:2014
    • EN 60079 60079-31:2014
  • Marking: II 2 G D
    • Ex db IIB+H2 T6 Gb
    • Ex tb IIIC T85°C Db
  • Ts= -40°C to +60°C IP6X

UKEX: Certificate: CML 21UKEX1086U

  • Standard: EN 60079 60079-0:2018
  • EN 60079 60079-1:2014
  • EN 60079 60079-31:2014

Marking: Group II 2 G D

  • Ex db IIB+H2 T6 Gb
  • Ex tb IIC T85°C Db
  • Tamb -40°C to +60°C
  • IP6X

IECEx : Certificate: IECEx CML 20.0168U

  • Standards:
    • EC 60079 60079-0:2017 Edition: 7.0
    • IEC 60079 60079-1:2014 2014-06 Edition: 7.0
    • IEC 60079 60079-31:2013 Edition 2
  • Marking:
    • Ex db IIB+H2 T6 Gb
    • Ex tb IIIC T85°C Db
  • Tamb – 40°C to +60°C IP6X

The flame arrestors do not include any polymeric or elastomeric materials.

Containment system with limited release (presence of fittings)

  • Description: The sample gas is completely confined inside 1/8” stainless steel tubing with Swagelok-type ferrule and ring compression fittings and tightened to Swagelok’s instructions, until exiting the enclosure.
  • Inlet pressure : specified regulated to 5-30 psig.
  • Flowrate: sample gas entering the enclosure: 1-2 SCFH Test realized according to annex G of EN 60079-0:2018 / IEC 60079-0:2017 for certification.

Cable gland
Analytical Industries does not supply the cable gland. It is the responsibility of the user to install a cable gland that complies with local regulations.

A unique label reflecting the sample above is permanently affixed to the enclosure to identify every analyzer.

Analytical-Industries-GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-
fig-1

The analyzer must be installed by:

  • EN 60079-14:2014; IEC 60079-14:2013
  • EN 60079-17:2014; IEC 60079-17:2013

Theory of Operation

These analyzers consist of two PCB assemblies, a sample system including a sample flow control valve and flow meter, and sensor housing, and, incorporate a variety of advanced electrochemical galvanic fuel cell type sensors for PPB, PPM, and % range oxygen measurements.
An optional temperature-controlled heater system is availa-ble that enhances the stability of the oxygen reading and is recommended for outdoor installations or when ambient temperatures vary regularly.
In standard configuration, the alarm controls are integral to the main PCB and cannot accessed from the outside of the analyzer (to prevent tampering with alarm set points)
The analyzer shall not have an internal source of release of oxygen or any other oxidizers in concentrations greater than 21%.

Sensor Technology
Oxygen enters the sensor, simultaneously oxidizes the an-ode, and reduces the cathode to produce a linear electrical current signal output proportional to the oxygen concentration in the gas phase.
Advanced sensor technology permeates the range of oxygen sensors which are:

  • specific to oxygen with superior accuracy
  • generate a signal output that is both linear over all ranges and virtually constant over its lifetime
  • exhibits superior stability and fast response time
  • requires no maintenance or electrolyte additions
  • easily replaced in the field like a battery
  • offer the best warranty and service in the industry

GPR-18 MS: Measures 10 PPB to 1000 PPM oxygen contamination in inert, hydrocarbon, He, H2, and mixed gases streams. It is based on a proprietary design, the Pico-Ion™ oxygen sensor which is specific to oxygen and produces a current signal output 80x greater than conventional electro-chemical fuel cells and equal to Coulometric wet cells.

info: The Pico-Ion sensor features a proprietary sensing electrode that generates an 80x increase in signal output and a unique gas delivery path that minimizes the amount of unreacted oxygen that can dissolve into the electrolyte and slow offline recovery time.
Sensitivity, stability, and recovery time are improved while significantly reducing the temperature dependence of the sensor’s signal output which contributes to excellent long-term stability.

GPR-18: Measures 50 PPB to 1% oxygen contamination in inert, hydrocarbon, He, H2, mixed, and acid (CO2) gas streams. Proprietary advancements in design and chemistry add significant advantages to an extremely versatile oxygen- sensing technology.
These PPM oxygen sensors exhibit superior accuracy and stability and recover from exposure to air to PPM levels in minutes with a longer life and warranty period. The XLT version offers an extended operating range of -20°C to 50°C and excellent compatibility for measuring PPM oxygen levels in applications involving natural gas and beverage-grade CO2 containing up to 100% CO2.

GPR-28: 0.05% to 21% oxygen measurements in inert, hydrocarbon, He, H2, mixed, and acid (CO2) gas streams. Proprietary advancements aid in the transition from PPM to low percentage range measurements to 21% oxygen.
In addition to superior accuracy and stability, the percent oxygen sensor offers the longest life and extended temperature range in the industry. The XLT version also offers an extended operating range of -20°C to 50°C and excellent compatibility for measuring oxygen levels in applications containing varying concentrations of CO2.

Signal Processing Electronics
The signal generated by the sensor is processed by an integrated electronic circuit. 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 30 seconds (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 the full-scale low range. The measured Oxygen value can be transmitted for external use via an isolated 4-20mA and 0-1V signal output.
  • Overall performance is enhanced by an optional tempera-ture controlled heater system that controls the tempera-ture around the sensor at a pre-set temperature.
  • Connections of the appropriate AC line voltage should be hard-wired to screw-type terminal blocks. Power requirement related to the optional heater system is specific to 100/110VAC or 220/230VAC, supply power as indicated near the power input terminal.

Essential Information

This section summarizes the general precautions and operating information for the Explosion Proof Series Oxygen Analyzers that must be observed to prevent damage to the analyzer and injury to the operator.
The remaining sections provide specific additional instruc-tions for optimizing the analyzer’s performance in inert sample gases. Analytical Industries Inc. will not be responsible for damages resulting from the installation or opera-tion of the analyzer in a manner not consistent with these Instructions for Use.

The analyzer shall not have an internal source of release of oxygen or any other oxidizers in concentrations greater than 21%.

Installation

Unpack & Inspect

  1. Examine the condition of the packaging, remove the contents identified below, and inspect.
    • Oxygen Analyzer
    • Instructions for Use (e-copy on a thumb drive)
    • Quality Control & Calibration Certification (sec 12)
    • Chart Recording of Qualification Test
  2. Verify the contents against the packing slip.
  3. Open the analyzer door, remove any shipping materials, and inspect with particular attention to components that may have come loose during transport.
  4. Report any apparent damage or missing items to the carrier and factory immediately (+1 909-392-6900 or in-fo@aii1.com). DO NOT proceed if damage is noted.

Overview
The following sections provide key information about the sensors, the influence of operating conditions, sample system requirements, mounting the analyzer, electrical connections, gas connections, establishing power to the analyzer, and installing the oxygen sensor.

warning: Install by ATEX Directives and IECEx Scheme:

  • EN 60079-14:2014; IEC 60079-14:2013
  • EN 60079-17:2014; IEC 60079-17:2013

Sensors
The GPR series sensor is available with all analyzers and recommended for all inert and hydrocarbon gas streams, whereas, the XLT series sensor is available only with the GPR-18 and GPR-28 analyzers and is recommended for background gases with more than 0.5% CO2 continually.

warning: Avoid prolonged exposure to air or high O2 levels.

  • GPR-12-2000 MS2 PPB oxygen sensors are susceptible to damage from prolonged exposure to > 1000 PPM O2.
  • GPR-12-333 PPM sensors last 4-6 months in prolonged exposure to air but generate a > 1-2 PPM O2 offset in the reading on zero gas. XLT-12-333 PPM sensors expire after 5-7 days in the air.
  • GPR-11-32 and XLT-11-24 % sensors are not adversely affected by exposure to ambient air.

info: See section 11 Specifications for the expected life of an oxygen sensor which is inversely proportional to changes in the oxygen concentration and pressure and exponential (2.54%/ C) to sample temperature, e.g. if an analyzer is continuously operated at 35 C, expect the sensor life to be reduced by ~30%.

Operating Conditions
The temperature of the sample gas must be within the recommended operating range specified in section 11 before it enters the analyzer.

info: Hot sample gases can easily be cooled to ambient temperature by using a coiled 10-foot (3m) length of ¼” stainless steel tubing. On an intermittent basis, the analyzer may be operated at 122°F (50 °C).

Sample Inlet Pressure

  • The analyzers are designed for flowing samples under positive pressure as standard. An optional Sample pump can be specified for negative pressure applications. See section 11 Specifications.
  • If the analyzer is equipped with an optional H2S scrubber and or a coalescing filter, inlet sample pressure must not exceed 30 PSIG.

WARNING: For sampling gases at near atmospheric pressure or under a slight vacuum an external sample pump can be used to either push or draw the sample gas from the process, and move it through the analyzer for analysis, and vent.
INFO: The positioning of the sample pump either upstream or downstream of the analyzer requires making an informed decision:

  1. The rate at which air (oxygen) leaks into the pump should be empirically determined.
  2. The user’s accuracy requirements must be assessed in light of the actual leak rate of the sample pump.
  3. If the sample pump has a low enough leak rate to meet the user’s accuracy requirements (a) position the pump upstream of the analyzer to draw the sample and push it through the analyzer, (b) the analyzer’s flow control device upstream of the sensor regulates the flow rate of the sample, a point that is critical to the GPR-18 MS, (c) the possibility of damaging the oxygen sensor is minimized, (d) this approach is the exception rather than the rule.
  4. To meet the user’s accuracy requirements or inability to confirm the actual leak rate of the sample pump position the pump downstream of the analyzer as the safest approach to obtaining reliable measurements.

DO NOT use a sample pump downstream of the GPR-18 MS. Using a sample pump downstream of the GPR-18 MS will damage the sensor. If a sample pump is used it must be suitable for the application and the area of installation.
GPR-18 and GPR-28 use an adjustable valve to control the flow rate. When a pump is positioned downstream of the analyzer, the adjustable valve MUST BE COMPLETELY OPEN to avoid drawing a vacuum directly on and permanently damaging the oxygen sensor.

Sample Vent Pressure

  • In positive sample pressure applications, the sample must be vented to ambient or in a vent line with pressure less than the sample inlet pressure.
  • If the sample is vented to a line at a pressure above or below ambient, a back-pressure regulator must be installed downstream of the oxygen sensor and set at least 1 PSIG higher than the line pressure of the vent to ensure constant pressure on the sensor.

INFO: When employing a back-pressure regulator to overcome a higher vent line pressure, e.g. venting a sample to a flare line, (a) set the back- pressure gradually to avoid drawing a vacuum on the sensor and (b) calibrate the analyzer after the back-pressure regulator has been set.

Sample System
Sample Gas Stream: Ensure that the sample gas composition and application conditions are consistent with the specifications of the analyzer. If in doubt, consult the factory to ensure the analyzer is suitable for specific gas analysis.

Material and Components
The analyzers can be specified and supplied with a sample handling system. However, if the analyzer was purchased without a sample handling system, the user may be required to install the necessary sample handling components.

WARNING: When designing a sample system, the use of stainless steel tubing, fittings, and valves is essential for maintaining the integrity of the sample gas stream.
Removal of Contaminant Gases: In certain applications, it may be necessary to remove any contaminants that may interfere with measurements. Typically, a gas-specific scrubber is used to remove interfering gases such as oxides of sulfur and nitrogen or hydrogen sulfide.

WARNING: The presence of such interfering gases can result in false oxygen readings and a reduction in the expected life of the sensor. Consult the factory for recommendations concerning the proper selection and installation of scrubber or filter components.

Mounting
The analyzers are packaged in an aluminum wall mount enclosure with dimensions of 13.25” x 17.25” x 10.75” which carries ATEX / IECEx certifications and IP66 rating.

WARNING: Only authorized trained personnel should install this analyzer. Installation must comply with local, state, and country regulations and the ATEX standards identified above.
WARNING/INFO: DO NOT connect electrical power until the analyzer is properly mounted.

The analyzer is designed for mounting on a flat vertical surface (mount approximately 5 feet above the floor) by bolting the mounting feet attached to the rear of the enclosure the mounting surface using 1/2″ or M12 diameter steel bolt and washers

WARNING:” Inspect and clean the machined surfaces of both the bottom base and the hinged cover of the enclosure. The sealing surfaces must be inspected and free of nicks, dirt, or any foreign particle build-up that would prevent a proper seal.

Closing the enclosure:

  1. Wipe the sealing surfaces with a clean lint-free cloth.
  2. Apply a light coating of Killark “LUBG” lubricant to the sealing surfaces.
  3. Close the hinged cover and mate to the enclosure base.
  4. Install the bolts through the cover into the enclosure base.
  5. Finger tighten bolts.
  6. Torque all bolts to 30 ft/lbs.

WARNING/INFO: After installation, the unit must be inspected regularly to verify the enclosure mounting bolts are tight and in good condition, the cover bolts are torqued to 30 ft/lbs., and conduit/cable gland connections are intact and free of corrosion.
Should the flange surface be damaged, NEVER attempt to rework the surface of a flange in the field. Consult the analyzer or enclosure manufacturer identified by one of the red metal labels affixed to the enclosure.

See the enclosure diagram on the following page.

Mounting – Enclosure Diagram

Analytical-Industries-GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-
fig-5 Analytical-Industries-
GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-fig-7

Electrical Connections

CAUTION: The analyzer electronics including the optional integral heater system are powered by 110 or 220 VAC power which must be specified at order entry. The analyzer’s power rating is located near the power input terminal.
INFO: Install cable glands, size 3/4”-14 NPT-M, or conduit using an approved electrical conducting type lubricant on the threads. The glands and conduit must be either a tapered type thread conforming to the o ANSI/ASME B1.20.1 standard or an ISO metric thread standard.
Supply power to the analyzer only as rated by the specification and markings on the analyzer enclosure.
WARNING The accessories used for cable gland entry, size 3/4”-14 NPT-M, must be covered by a separate ATEX certificate and must be suitable to be used with the enclosure, see Appendix A.
WARNING Ensure that the analyzer is properly grounded, see illustration below and meets the requirements of recommended local electrical standards.

Power Consumption: The analyzer consumes a maximum of 30 watts of power without the optional heater and 93 watts with the built-in optional heater system.
Power must be supplied through a separate conduit on the left side of the enclosure, see drawing previous page.
Use a shielded power cord with a minimum of 18 gauge wires. If equipped with the optional integral heater system, the required internal wiring to the heater and controller has been installed at the factory.
The user simply connects an appropriate source of AC power to the power terminal as illustrated below. Bring the output and alarm connections through an approved 3/4″-14 NPT-M conduit fitting on the right side of the enclosure, see the drawing on the previous page.

WARNING

The electronics are rated for 110 or 220 VAC. Supply appropriate AC power of power. An improper voltage could permanently damage the heating system. Do not remove the protective Plexi-glass panel that covers the PCB. The cover prevents the user from touching any of the LIVE circuitry on the PCB.
If authorized by the factory to replace failed components in the analyzer, disconnect the AC power source to avoid electric shock. There is no AC power present on the circuit board assemblies mounted on the inside of the analyzer door.

See power and electrical feature connections, interconnection wiring, and optional heater wiring diagrams along with installation procedures on the following pages.

Electrical Connections

Analytical-Industries-GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-
fig-9

Procedure

  1. Insert the power cable through the user-supplied ATEX-approved conduit fitting on the left side of the analyzer.
  2. Insert the signal output cable(s) through the user-supplied ATEX-approved conduit fittings on the right side of the analyzer.
  3. Strip the ends of the wires approximately ¼ inch.
  4. Loosen the terminal screws, insert the bare wire into the appropriate terminals, and re-tighten with a small bladed screwdriver.
  5. Note: If equipped with the optional temperature-controlled heater system, the necessary wiring to the heater and controller has been installed at the factory and no additional connections are required. The power connection services both the analyzer electronics and the temperature-controlled heater system.
  6. Connect the power ground directly to the ground terminal on the inside of the analyzer case, see previous page.
  7. Pack and seal the seal fittings bringing power to and taking analog outputs and alarm interconnection wiring from the analyzer as recommended in Appendix A.
  8. Establish power to the analyzer after making gas connections as below once installation is complete.

Electrical Connections – Analyzer Interconnection Diagram

Analytical-Industries-GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-
fig-10Analytical-Industries-
GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-fig-11

Gas Connections

  • The analyzer’s flow-through configuration is designed for positive pressure samples and requires connection to 1/4’” diameter compression tube fittings. Addressing different sample conditions was discussed previously.
  • Complementing the performance capabilities of the PPB (GPR-18 MS) and PPM (GPR-18) oxygen sensor is a sample system consisting of stainless steel and glass wetted parts, a unique proven leak-tight sensor housing design, and a sample/bypass system.

INFO: The bypass system isolates the sensor from exposure to high oxygen concentration during transport, upset conditions, and routine maintenance and brings the analyzer online at PPB and PPM levels very quickly. The sample/bypass valve is not required for the GPR-28.

Analytical-Industries-GPR-18-MS-Explosion-Proof-Oxygen-Analyzers-
fig-12

Establish Power to Electronics
Connect a power cable to the analyzer’s power terminal block. The electronics are rated for a power input of 100 or 230 VAC 50-60 Hz. An optional temperature-controlled heater system, however, supplies only the voltage noted near the power terminal.

The LCD will light up when power is applied to the analyzer. Assuming the analyzer has been installed as directed above, and the sensor has been installed at the factory, the reading displayed when the analyzer is turned on reflects the oxygen value under static conditions (i.e. the axiom that all valves and fittings leak, the sensor is looking at equilibrium point of oxygen diffusing into the sample system and oxygen consumed by the sensor).

Installing the Oxygen Sensor

  • Analyzers are shipped with the oxygen sensor that the analyzer was calibrated, qualified, and tested with at the factory as documented by the Quality Control & Calibration Certification and chart recordings in section 12.
  • Circumstances vary but normally the oxygen sensor is installed before shipment and the analyzer is fully operational out of the box.

If the oxygen sensor was shipped separately or if a new oxygen sensor must be installed in the field, it will be necessary to install a new sensor.

  • The sensor is sealed in a special bag under application conditions. DO NOT open the bag until ready to install the sensor.
  • DO NOT open the oxygen sensor. The sensor contains a corrosive liquid electrolyte that could be harmful if touched or ingested, refer to section 10 Safety Data Sheet. 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. A spent sensor or a leaking sensor should be disposed of by local regulations.
  • After sensor installation, the analyzer must be calibrated to ensure correct sample analysis. Review section 4 Calibration to determine whether the next step is Zero or Span Calibration.
  • Depending on the circumstances and type of oxygen sensor, there are several procedures with different requirements as described on the next page.

Procedure Applicable to GPR-18 MS and GPR-18 if Zero Calibration is to follow (section 4 Calibration):

  1. Select the analyzer’s highest range available range, and adjust as the reading trends downward.
  2. Initiate the flow of a high purity N2 zero gas, regulate the pressure to the lowest value expected in the sample gas, and then set the flow rate, see section 11 Specification.
  3. Place the Sample/Bypass valve in the Sample position before installing the oxygen sensor.
  4. Use the 5/16 wrench supplied to loosen the clamp bolt under the sensor housing.
  5. With the bolt loose, rotate the upper sensor housing 90° to disengage it from the clamp.
  6. Remove the oxygen sensor from the bag (if replacing an existing sensor see section 6).
  7. Place the oxygen sensor in the bottom section of the sensor housing, PCB facing up.
  8. Remove the two red shorting strips (including the gold ribbon) from the sensor’s PCB.
  9. Place the upper section of the sensor housing over the oxygen sensor, gently push downward, and rotate 90°to engage the clamp.
  10. Use the 5/16 wrench to re-tighten the clamp bolt.
  11. The analyzer will display the O2 content of the gas.
  12. Confirm the downward trend of the O2 concentration with an external recording device.
  13. Proceed to section 4 Calibration to complete Zero Calibration

Procedure Applicable to GPR-18 MS, GPR-18 and GPR-28 if Span Calibration is to follow:

  1. Select the range that accommodates the O2 content of the span gas, see section 11 Specification.
  2. Initiate the flow of span gas, regulate the pressure to the lowest value expected in the sample gas, and then set the flow rate, see section 11 Specification.
  3. Place the Sample/Bypass valve in the Sample position before installing the oxygen sensor.
  4. Use the 5/16 wrench supplied to loosen the clamp bolt under the sensor housing.
  5. With the bolt loose, rotate the upper sensor housing 90° to disengage it from the clamp.
  6. Remove the oxygen sensor from the bag (if replacing an existing sensor, see section 6).
  7. Immediately place the oxygen sensor in the bottom section of the sensor housing, PCB facing up.
  8. Remove the two red shorting strips (including the gold ribbon) from the sensor’s PCB.
  9. Place the upper section of the sensor housing over the oxygen sensor, gently push downward, and rotate 90° to engage the clamp.
  10. Use the 5/16 wrench to re-tighten the clamp bolt.
  11. The analyzer will immediately display the oxygen content of the gas.
  12. Confirm the downward trend of the O2 concentration with an external recording device.
  13. Proceed to section 4 Calibration.

Procedure Applicable to GPR-18 and GPR-28 if Air Calibration is to follow:

  1. Select the range of the analyzer to the 0-25% range.
  2. Initiate the flow of sample gas, regulate the pressure to the lowest value expected in the sample
  3. Gas and then set the flow rate, see section 11 Specification.
  4. Place the Sample/Bypass valve in the Sample position before installing the oxygen sensor.
  5. Use the 5/16 wrench supplied to loosen the clamp bolt under the sensor housing.
  6. After loosening the bolt, rotate the upper sensor housing 90° to disengage it from the clamp.
  7. Remove the oxygen sensor from the bag (if replicating an existing sensor, see section 6).
  8. Remove the two red shorting strips (including the gold ribbon) from the sensor PCB.
  9. Proceed to section 4 Calibration and follow the Air Calibration procedure.
  10. Upon completion of the Air Calibration procedure, immediately place the new sensor in the bottom section, PCB facing up.
  11. Place the upper section of the sensor housing over the sensor, gently push downward, and rotate 90° to engage the clamp.
  12. Use the 5/16 wrench to re-tighten the clamp bolt.
  13. The analyzer will immediately display the O2 content of the gas.
  14. Confirm the downward trend of the O2 concentration with an external recording device.

Calibration

To accurately measure the oxygen concentration in a sample gas stream, it is necessary to calibrate (adjust the accuracy) the analyzer electronics to the oxygen sensor’s signal output when exposed to certified gas standards. Calibration can involve one or both Zero and Span Calibrations.

INFO: The user is responsible for making provisions for calibration gases and regulating the sample and span gas pressure and flow as described below.

Recommendation : Consider installing 3-way valves before the sample inlet to provide a permanent connection for Zero gas (if required) and/or Span gas and a means of switching from SAMPLE to ZERO or SPAN gas and vice versa without breaking gas line connections. This arrangement eliminates the possibility of exposing the sensor to high oxygen when changing gas lines to switch gas sources.

Accuracy

  • Single Point Calibration : The galvanic oxygen sensor generates an electrical current that is both linear and proportional to the oxygen concentration in the sample gas.
    In the absence of oxygen, the sensor exhibits an absolute zero, e.g. the oxygen sensor does not generate a current signal output in the absence of oxygen. Given the specificity, linearity, and absolute zero properties, a single-point calibration of the analyzer is possible.

  • Pressure: Galvanic oxygen sensors are accurate at any pressure provided the pressure is constant. Oxygen sensors are sensitive to the partial pressure of oxygen in the sample gas and their output is a function of the number of oxygen molecules ‘per unit volume’ of the sample gas. The number of oxygen molecules per unit volume will increase proportionally with pressure.

INFO: Expected sensor life is inversely proportional to pressure.

Because pressure varies in real-world applications, a flow control device is positioned between the pressure regulator and the oxygen sensor to reduce and stabilize the pressure at the oxygen sensor. The type of flow control valve or fixed restrictor varies with the flow sensitivity of the oxygen sensor.
The GPR-18 MS oxygen sensor is more flow sensitive and requires the precision of a flow restrictor, whereas, the membrane-clad oxygen sensors found in the GPR-18 and GPR-28 are not flow sensitive and use a metering valve to maintain the pressure.

INFO: Flow devices can minimize the influence of increasing pressure but a drop in pressure changes the partial pressure at the oxygen sensor.
WARNING: To prevent erratic oxygen readings, set the flow rate only after the pressure is regulated, see section 11 Specifications, at the lowest pressure anticipated under-sampling conditions.

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. All diffusion processes are temperature sensitive, the sensor’s electrical signal output also varies with temperature.
INFO: Changes in temperature result in a 2.54%/ºC variation in the sensor’s signal output which inversely affects expected sensor life.

With reference to Dalton’s Law of partial pressure, the oxygen diffusion limiting barrier allows and requires a small amount of the actual sample to permeate into the sensor to make the oxygen measurement. This provides several performance advantages:

  1. Unaffected by changes in flow rate, 0.1 to 10 SCFH.
  2. Unaffected by changes in background gases (except GPR-12-2000 MS2 Pico Ion PPB oxygen sensor).
  3. Unaffected by moisture and particulates.

A temperature compensation circuit offsets the 2.54%/ºC variation in the sensor’s signal output once the electronics and sensor’s diffusion barrier and electrolyte reach equilibrium. Accuracy is +5% full-scale range over the operating temperature range, see section 11 Specifications.

INFO: A variation of ~10º F produces < 2% FS error in the O2 reading until equilibrium is reached.
WARNING: To prevent erratic oxygen readings, calibrate the analyzer at the temperature nearest the tempera-ture anticipated under-sampling conditions

Calibration Gas Preparation
It is essential that when using a certified standard zero or span gas to adjust the analyzer sensitivity the integrity of the gas is maintained during the installation of a pressure regulator (on the gas cylinder) to regulate the gas pressure when making
gas connection to the analyzer.

Required Components

  1. Certified zero or span (as recommended in section 11 Specifications) gas cylinder.
  2. Regulator to set gas pressure to 5-30 psig.
  3. Suitable fittings and 1/8” or 1/4″ dia. metal tubing to connect the regulator to the flow meter/analyzer SAM-PLE IN inlet
  4. Suitable fitting and 1/8” or 1/4″ metal tubing to connect from the flow meter vent to the analyzer tube fitting designated as SAMPLE OUT.
    Use an additional flow meter only if the analyzer is not equipped with an integral flow meter.

Procedure:

  1. With the span gas cylinder valve closed, install the 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 and then close the regulator exit valve.
  8. Set the pressure as specified in section 11 using the pressure regulator’s control knob.
  9. Caution: Do not exceed the recommended flow rate. The excessive flow rate could cause backpressure on the sensor and may result in erroneous readings and permanent damage to the sensor.

Zero Calibration

Zero Calibration (preceding Span Calibration) is required for optimum accuracy only when analyzing a sample with an expected value of less than 5% to 10% of the most sensitive range available. Perform a Zero Calibration when initially installing the analyzer, the customer’s sample system is interrupted, and a new sensor is installed.

Zero Calibration produces an adjustment that is too small to affect the accuracy and thus is not recommended for the following measurements :

  1. Above 10% of the most sensitive ranges on the GPR-18 MS and GPR-18.
  2. 99% of percent range applications involving the GPR-28, which has no Zero Calibration capability.

In theory, the galvanic fuel cell type oxygen sensor has an absolute zero meaning it does generate a signal output when exposed to an oxygen-free zero gas.
In reality, the sensor generates a signal output or positive oxygen reading when sampling a zero gas due to:

  1. Minor leakage in the sample line connections.
  2. Impurities in the zero gas, e.g. accuracy % tag.
  3. Tolerances of the electronic components.
  4. Lack of quality control during the manufacturing of the sensor results in residual oxygen dissolved inside the sensor.

The term ZERO OFFSET is applied to the fully stabilized oxygen reading evidenced by a flat horizontal trend on an external recording device after 12-30 hours of continuous exposure to flowing high-purity zero gas.

This horizontal trend indicates:

  1. The sensor has consumed all the oxygen that dis-solved into the sensor’s electrolyte during installation or exposure to high levels of oxygen,
  2. The remaining oxygen value represents the total of elements 1-4 listed above,
  3. The ZERO OFFSET value the analyzer electronics will deduct from all subsequent readings including Span Calibration for optimum accuracy.

INFO: The manufacturer’s Quality Control testing before shipment confirms the zero offset, above, is within acceptable limits. However, owing to the differences in the user’s sample system leakage and zero gas accuracy, no Zero Calibration adjustment is made by the factory.
INFO: The following Zero Calibration procedure assumes the user is installing the analyzer for the first time.

Procedure for Zero Calibration

  1. Connect the zero gas to either the sample inlet or the Zero/Span valve if present.

  2. Connect an external recording device to monitor the trend of the reading to the 0-1V or 4-20 mA analog signal outputs.

  3. Refer to section 11 Specifications and set the pressure and flow rate as specified.

  4. Initiate the flow of ultra-high purity nitrogen zero gas to the analyzer.

  5. Allow 12-30 hours for the O2 trend to stabilize parallel to the X-axis on the external recording device.
    The time required for stabilization, clean-up, recovery, and purge down depends on:

    • If the gas lines were adequately purged.
    • Quality of the zero gas,
    • Length of time the sensor was exposed to ambient air during installation, e.g. red shorting devices removed (unsorted) before being connected (shorted) to the upper section of the sensor housing.
  6. If after 2 hours, the oxygen value displayed is not below 5 PPM, perform a complete check of all external sample system connections and allow the zero gas to flow overnight before concluding the sensor is defective and notifying the factory.

  7. Once the analyzer reading stabilizes, the reading should be well below 50% of the most sensitive range, the limit of the ZERO OFFSET adjustment.
    WARNING: Prematurely adjusting the ZERO control knob will result in erroneous low or even negative oxygen readings when sampling gases with very low O2 concentrations.

  8. Turn the ZERO knob on the analyzer’s front panel ½ turn at a time until the analyzer display reads 0.00 to complete the Zero Calibration and activate the ZERO OFFSET.

  9. Place the Sample/Bypass valve in the Bypass position before disconnecting the zero gas line.

  10. Connect the span gas line as described previously and allow the span gas to flow for 30 seconds to purge the ambient air through the gas lines.

  11. Proceed to SPAN CALIBRATION

WARNING: Subsequent Zero Calibration requires eliminating the previous ZERO OFFSET

Changes such as:

  • Replacing the oxygen sensor
  • Servicing the user’s sample system
  • Replacing an electronic PCB or other component
  • Correcting for zero drift as determined by repeating the Zero Calibration procedure above.

require eliminating the prior ZERO OFFSET and performing a new Zero Calibration to establish a new ZERO OFFSET.

Procedure for Eliminating the Zero Offset:

  1. Loosen the top section of the sensor housing, twist it 90 degrees, and pull it up until it disengages from the sensor.
  2. The resulting reading represents the ZERO OFFSET stored in the analyzer electronics.
  3. Allow the reading to stabilize.
  4. Adjust the ZERO knob on the analyzer’s front panel until the analyzer reads 0.00.
  5. After eliminating the ZERO OFFSET, the reading on all ranges should be zero with +/- one digit of the range.

Install the oxygen sensor and perform a new Zero Calibration as described above.

Span Calibration
Involves periodically adjusting the analyzer electronics to the sensor’s signal output when it is exposed to a gas with a known oxygen content, see below or section 11.

Recommended Calibration Gases:

  • GPR-18 MS: certified span gas of 7.5-9 PPM oxygen balance nitrogen.
  • GPR-18 : certified span gas of 75-90 PPM oxy-gen balance nitrogen or clean source ambient air 20.9% oxygen.
  • GPR-28 : clean source of ambient air 20.9%oxygen or a certified span gas oxygen balance with the oxygen content approximating 75–90% of FS.

The frequency of calibration varies with the application conditions, the degree of accuracy required, and the Quality Assurance requirements of the user.

  • INFO: Ensure accuracy, and allow the oxygen reading to stabilize on the certified span gas standard before making the Span Calibration adjustment.
  • WARNING: The Span Calibration process itself only takes 15-30 minutes. However, the time required to bring the analyzer back online can vary depending on the span gas used, exposure time, and purging of the sensor after Span Calibration with the lowest oxygen concentration gas available.
  • INFO: Recommendations to minimize downtime (see Recovery section 11 Specifications):

GPR-18 MS PPB Oxygen Analyzer:

  1. 1. Minimize exposure of the sensor to air when installing the new sensor,
  2. 2. DO NOT calibrate with span gas containing more than 900 PPM oxygen balance nitrogen.
  3. 3. Change the gas line immediately upon completion of Span Calibration to the lowest oxygen concentration gas available and purge:
    • place the Sample/Bypass valve in the Bypass position,
    • change the gas lines from Span to the lowest oxygen concentration gas available,
    • initiate the flow of low oxygen con-centration gas and purge the gas lines for 30 seconds,
    • place the Sample/Bypass valve in the Sample position, allow the analyzer reading to stabilize,
    • If the lowest oxygen concentration gas was not the sample gas, repeat (3) above with the sample gas.

GPR-18: As above, except #2 is not applicable.
GPR-28: No special requirements.

Procedure Span Gas Calibration

  1. Place the Sample/Bypass valve in the Bypass position.
  2. Connect the span gas line to either the SAMPLE INLET or Zero/Span valve if present.
  3. Connect a metal vent line to the fitting designated SAMPLE OUT or VENT.
  4. Optional: Connect an external recording device to monitor the trend of the reading to the 0-1V or 4-20 mA analog signal outputs.
  5. Assure there are no restrictions in the vent line.
  6. Initiate the flow of the span gas to the analyzer.
  7. Set the pressure and flow rate as described in the preceding sub-section titled Accuracy.
  8. Purge the gas lines with span gas for 30 seconds.
  9. Place the Sample/Bypass valve in the Sample position.
  10. The sensor will detect the oxygen content in the span gas and the analyzer’s reading will move toward it.
  11. Ensure accuracy, and allow the oxygen reading to stabilize (15-30 minutes) on the certified span gas standard before making the Span Calibration adjustment.
  12. Turn the SPAN knob on the analyzer’s front panel ½ turn at a time until the analyzer displays the oxygen content of the certified span gas standard.
  13. Place the Sample/Bypass valve in the Bypass position before disconnecting the span gas line.
  14. Connect the sample gas line as described previously and allow the sample gas to flow for 30 seconds to purge the ambient air through the gas lines.
  15. Proceed to sample.

Procedure Ambient Air Calibration

WARNING: DO NOT calibrate the GPR-18 MS with a span gas containing more than 900 PPM oxygen balance nitrogen.

  1. Place the analyzer in the OXYGEN mode and select the CAL (0-25%) range.
  2. Access the interior of the analyzer by removing the bolts securing the front door.
  3. Using the 5/16 wrench supplied, loosen but do not remove the clamp bolt holding the two sections of the sensor housing.
  4. Rotate the upper section of the sensor housing 90º to disengage from the clamp.
  5. Remove the upper section by pulling it straight up and let it rest on your 1st and 2nd fingers.
  6. With your other hand, remove the oxygen sensor from the bottom section of the housing.
  7. Place the sensor in the upper section of the sensor housing ensuring the PCB contacts the two gold pins.
  8. Use your thumb (see photo right) to hold the sensor and the upper section of the sensor housing together.
  9. With the sensor exposed to ambient air – allow the reading to stabilize for 1-2 minutes.
  10. After the reading stabilizes, turn the SPAN knob until the LED display reads the 20.9%.
    1. After air calibration, reinstall the sensor as previously described.
  11. With sample gas flowing, the oxygen reading will start trending down.
  12. Manually turn the RANGE selector switch to lower ranges and follow the progress of the sensor’s recovery, see section 11 Specifications.
  13. Proceed to sample.

Sampling
After ZERO and SPAN calibration, the analyzer is ready to analyze the sample gas stream. Select the appropriate range of interest by turning the RANGE selector switch to the desired range.

INFO: If the oxygen concentration is higher than the selected range, the display will show 1– indicating an over-range condition. If this occurs, select a higher range until the display shows an oxygen reading.
Adjust the flow rate if necessary as specified in section 11.

Operation

  • As detailed in Section 1 Introduction, the Explosion Proof Series of Oxygen Analyzers are designed with an explosion-proof enclosure, flame arrestors, breather device, actuators, and ATEX certified for use in hazardous areas.
  • The preceding sections 2, 3, and 4 detail the basic do`s and don’ts, setup, and calibration information, and review them.
  • The analyzer shall not have an internal source of release of oxygen or any other oxidizers in concentrations greater than 21%.

Analyzer Features

Oxygen Display
The analyzers are equipped with a 3-1/2 digit LED display that shows oxygen concentration from PPB to % level depending on the range of analysis selected.

Display Mode Selection
The DISPLAY SELECT slide switch (circled in red in the photo at right) is located on the main signal processing PCB mounted on the inside of the analyzer’s front door. The slide switch has been set to the O2 position at the factory. Advance this slide switch to select one of the three available DISPLAY modes:

  • OXYGEN to display the oxygen reading
  • ALARM 1 to set Alarm 1 Setpoint
  • ALARM 2 to set Alarm 2 Setpoint

Oxygen Alarms
The analyzers are equipped with two user-adjustable alarms that when activated trigger SPDT Form C, normally closed, non-latching relays rated @ 5A, 30VDC, or 240VAC resistive.
The alarm set point represents a value. When the oxygen reading exceeds ALARM 2 (high alarm) or falls below ALARM 1 (low alarm) set point, the corresponding relay is activated.

INFO

  • The alarms are fully adjustable by the two potentiometers accessible from the auxiliary panel (circled in yellow in the photo at right) on the inside of the door with a small bladed screwdriver. Optionally, the alarm controls might have been installed external to the analyzer by using actuators.
  • To configure alarms as “Failsafe” (inactive when energized) – connect the positive lead to NO and negative to the C, common or neutral.
  • To connect to an active relay, connect the live cable to the common terminal C and the secondary cable to the normally open NO terminal.
  • To break the connection upon relay activation, connect the secondary cable to the normally closed NC terminal.
  • To prevent chattering of the relays, the alarm will remain active until the oxygen reading has fallen 2% below the alarm set point (high alarm) or risen 2% above the alarm set point (low alarm) after the alarm was activated.

Procedure (see photo below):

  1. Open the front door to access the DISPLAY SELECT slide switch (highlighted in red) located on the A-1107 PCB Assembly Main/Display.
  2. Slide the switch to the ALM1 (high) or ALM2 (low).
  3. The LED display indicates the current alarm set point.
  4. The set point is displayed as a value on a given range.
  5. Use a small bladed screwdriver to adjust the potentiometer slowly, a ½ a turn at a time to allow the elec-tronic processing to catch up . . . until the display reads the desired alarm set point value.
  6. Once the alarm values are set, slide the DISPLAY SE-LECT switch back to the OXYGEN position.

Power Fail Alarm
A dry contact rated at 1A @ 30 VDC is provided as a power failure alarm. The contact is normally open but closes when the power to the analyzer is switched off or interrupted.

Sensor Fail Alarm
A relay contact rated at 1A @ 30 VDC is provided for the sensor fail alarm. The contact is normally open but closes when the oxygen signal goes to zero or falls below zero.

INFO: Adjusting the ZERO OFFSET to 00.00 activates the Sensor Failure Alarm possibly causing a spike in the trend analysis. To avoid the momentary spike, set the ZERO OFFSET to 0.01 PPM. The sensor failure alarm becomes active when the display indicates ‘000’ on any range of the analyzer.

Operation

Signal Outputs
The analyzer provides an isolated 4-20mA signal output and a 0-1V full-scale signal output for external recording devices. The integral IC on the main PCB converts the 0-1V signal with negative ground to a 4-20mA fully isolated signal. A finer adjustment of the zero offset of the 4-20mA converter can be provided by a potentiometer, R99, mounted on the main PCB Assembly. Consult the factory for instructions.

DO NOT supply any voltage to either of the two terminals of the 4-20mA converter. Supplying power to 4-20 mA IC will permanently damage the IC. The integral 4-20mA converter is internally powered and does not require external power.

Range ID
A voltage output corresponding to each range is provided. The output of the highest range (normally CAL) is 5V. The range ID voltage will change by 1V with each remaining range.

Temperature Controlled Heater System
If the optional temperature-controlled heater system is installed, the temp controller is accessible only by opening the front door of the enclosure. The controller is PID and is set at the factory to maintain the analyzer interior tempera-ture at 85°F (30°C)

WARNING: DO NOT change this setting. A higher temperature setting may drastically reduce sensor life and possibly cause damage to the electronic circuitry of both the controller and the analyzer. When power is applied to the temperature controller, the controller initially tunes itself and then maintains the temperature at the set point.

It is recommended that at initial start-up, or when replacing the oxygen sensor or when troubleshooting, set the set point around 60°F (15°C) to turn the heater off (to prevent overheating othe f heater elements).

WARNING: Keep the analyzer front door closed and securely fastened when the temperature controller is ON.

Heater Runaway Protection
As part of the optional temperature-controlled heater sys-tem, the analyzer is protected in the event the temperature controller should fail thereby allowing the heater to run away damaging the interior of the analysis unit.
The protection is provided by a J2-type device positioned between the temperature controller and the heater. This device cuts off power to the heater if the temperature inside the enclosure exceeds 158oF (70°C). Should the F2 device fail, correct the problem and replace J2.

Range Selection
See section 11 Specifications: the analyzers are equipped with four (4) standard measuring ranges. The GPR-18 is equipped with a 5th range of 0-25% for air calibration only. The ranges available are indicated around the RANGE selector knob located in the center of the control panel of the analyzer. Simply turn the pointer on the RANGE knob to the desired range.

The analyzer shall not have an internal source of release of oxygen or any other oxidizers in concentrations greater than 21%.

INFO: If the oxygen concentration is higher than the selected range, the display will show 1—- indicating an over-range condition. Select a higher range until the oxygen reading is displayed.
WARNING: Before concluding the sensor is not “coming down to expected ppb or PPM levels” or “is not responding to sample gas”:

  1. Confirm that the display selector switch (highlighted in red in the photo on the previous page) inside of the enclosure door is positioned to the far right in the OXYGEN DIS-PLAY.
  2. Perform a flow test as described in section 8 Troubleshooting to check for leaks in the sample system connections.
  3. Perform a Span Calibration, as this condition could result from not allowing the oxygen reading to stabilize beforadjustingnt.

Standby

  • The analyzer has no special storage requirements.
  • The sensor should remain installed in the sensor housings during storage periods – place the 4-way SAMPLE/ BYPASS crossover valve in the BYPASS position.
  • Store the analyzer with power OFF.

Maintenance

The extent of the maintenance requirements of this analyzer involves periodically replacing the oxygen sensor, cleaning and lubricating the o-ring in the sensor housing, and the machined surfaces of the analyzer cover and bottom section.

  • INFO: While none of the components are serviceable in themselves, section 7 Spare Parts is provided in the unlikely event a component fails and has to be replaced.
  • INFO: DO NOT attempt to service the analyzer or replace parts on your own, consult the factory or a factory-trained service technician. Please review section 9 Warranty.

Sensor Replacement
Periodically, the oxygen sensor will require replacement. Section 11 Specifications defines the normal operating con-ditions and expected life of the various sensors employed by the various analyzers.
Section 4 Calibration and accuracy define the factors that can influence the expected life of oxygen. In reality, expected sensor life is determined by several factors that are influenced by the user and therefore virtually impossible to predict.

  • DO NOT open the oxygen sensor. The sensor contains a corrosive liquid electrolyte that could be harmful if touched or ingested, refer to section 10 Safety Data Sheet for information.
  • Install the replacement oxygen sensor as outlined in section 3 Installation, Installing the Oxygen Sensor.
  • Remove the existing sensor and dispose of to local regulations.

Analyzer Enclosure
Inspect and clean the machined surfaces of both the bottom base and the hinged cover of the enclosure.
The sealing surfaces must be inspected and free of nicks, dirt, or any foreign particle build-up that would prevent a proper seal.

Cleaning & Closing the enclosure:

  1. Wipe the sealing surfaces with a clean lint-free cloth.
  2. Apply a light coating of Killark “LUBG” lubricant to the sealing surfaces.
  3. Close the hinged cover and mate to the enclosure base.
  4. Install the bolts through the cover into the enclosure base.
  5. Finger tighten bolts.
  6. Torque all bolts to 30 ft/lbs.

WARNING: After installation, the unit must be inspected regularly to verify the enclosure mounting bolts are tight and in good condition, the cover bolts are torqued to 30ft/lbs., and conduit/cable gland connections are intact and free of corrosion.
DO NOT attempt to repair the flange sealing sur-faces should they appear to be damaged, they are not intended to be repaired. Contact the analyzer or enclosure manufacturer identified by one of the red metal labels affixed to the enclosure.

Troubleshooting: Consult the guidelines in section 8 for advice on the common operating errors before concluding that your analyzer is faulty. Do not attempt to service the analyzer beyond those means described in the Instructions for Use.

Spare Parts

Description GPR-18 MS GPR-18 GPR-28

Oxygen Sensor(s)

|

GPR-12-2000 MS2

| GPR-12-333| GPR-11-32
XLT-12-333

(CO2 Background)

| XLT-12-333

(CO2 Background)

| | |
PCB Assy Power / Interconnection| A-1107-MS2| A-1107-M| A-1107-C
Sample Panel Assy| A-4753| A-4565
Sensor Housing Assy SS| A-1004-4-3-14| A-1004-4-3-5
Sensor Housing SS Upper Assy w/Cable| B-2762-B-2-32| B-2762-A-2-32
Valve 4-way Sample/Bypass| VALV-1031| Not Applicable
Amplifier E/I converter| IC-1007
Breather Device 1/2″ NPT| ENCL-1146
Controller Temperature| CTRL-1004
Flame Arrestor 1/2″ NPT| FITN-1262
Flowmeter Assy| A-4565
Flowmeter SS, Max Inlet 200 psig, 1/8″ FNPT,

Scale 5

| FMTR-1002
Fuse Holder for TR5 Fuse| FUSE-1003
Fuse 3A TR5 Series 250VAC| FUSE-1010
Heater Rod 75W 240VAC| HTR-1006
LCD 3.5 DGT 2VFS (29 / 19)| MTR-1002
O-Ring Viton Black Size -126| ORNG-1007
PCB Assy Main / Display| A-1106-C
Sensor Housing SS Bottom Assy| A-4541-4
Sensor Temperature Pepi J2 Runaway Protector| SNSR-1002
Temperature Sensor RTD| SNSR-1006

Troubleshooting

Symptom Possible Cause Recommended Action
Slow recovery or response time At installation, a defective sensor

Failure to purge gas lines with Bypass, air leak in connections, dead legs, distance of sample line, low flow rate, volume of optional filters and scrubbers

Abnormality in zero-gas

Damaged in service – prolonged exposure to air, electrolyte leak

Sensor nearing the end of life

| Replace the sensor if recovery is unacceptable or the O2 reading fails to reach 10% of the lowest range

Leak test the entire sample system:

Vary the flow rate, if the O2 reading changes inversely with the change in flow rate it indicates an air leak – the correct source of the leak

Qualify zero gas (using a portable analyzer)

Replace sensor Replace sensor

High O2 read- ing

after installing or replacing the sensor

| Analyzer calibrated before sensor stabilized caused by:

1)   Prolonged exposure to ambient air, worse if the sensor was unsorted

2)   Air leak in sample system connection(s)

3)   Abnormality in zero gas

| Allow the O2 reading to stabilize before making the span/calibration adjustment

Continue purge with zero gas

Leak test the entire sample system (above) Qualify zero gas (using a portable analyzer)

High O2 read-

ing Sampling

| Flow rate exceeds limits

Pressurized sensor

Improper sensor – CO2 affects the GPR sensor Abnormality in gas

| Correct pressure and flow rate

Remove restriction on vent line, replace the sensor

Use XLT sensor when CO2 or acid gases are present

Qualify the gas (use a portable analyzer)

Reading doesn’t agree with expected O2 values| The pressure and temperature of the sample are different than those span gas

Abnormality in gas

Failure to allow reading to stabilize before zero and/or span calibration adjustments

Calibration error caused by turning the zero and/or span potentiometer more than ½ turn at a time (electronics need time to keep up

| Calibrate the analyzer (calibrate at the pressure and temperature of the sample)

Qualify the gas (use a portable analyzer)

Repeat the calibration procedure and allow the read- ing (sensor) to stabilize

Repeat calibration, allow reading to stabilize, and make adjustments ½ turn at a time

Symptom Possible Cause Recommended Action
Erratic O2 reading Change in sample pressure

Dirty electrical contacts in the upper section of the sensor housing

Corroded solder joints on the sensor PCB from the corrosive sample or electrolyte leakage from the sensor

Corroded spring-loaded contact in the upper section of the sensor housing from the liquid in the sample or electrolyte leakage from the sensor

Liquid covering sensing area

Presence of interference gases Presence of sulfur gases and/or CO2 Unauthorized maintenance

| Repeat calibration at the temperature and pressure of the sample

Clean contacts with alcohol (minimize exposure time of MS sensor to ambient air to ex-tent possible)

Replace the sensor and return the sensor to fac- fac-

tory for warranty determination

The upper section of sensor housing: Clean contacts with alcohol, flow sample, or zero gas for 2-3 hours to flush the sample system and sensor housing

Sensor: Replace if leaking and return it to the factory for warranty determination

Wipe with alcohol and lint-free towel or flow sample or zero gas for 2-3 hours to flush

Consult factory

Replace the sensor and install a scrubber, contact the factory

Replace the sensor, obtain authorized service

No O2 reading Negative O2 reading| Failure of an electronic component or power surge that sends a charge to the sensor

Pressurizing the sensor by:

a)  Flowing gas to the sensor with the vent restricted or SHUT OFF valve closed and suddenly removing the restriction draws a vacuum and can damage the sensor and/or cause electrolyte leakage

b)  Drawing a vacuum on the sensor by partially opening the FLOW valve upstream of the sensor when using a pump downstream to draw samples from a process at atmospheric pressure or a slight vacuum can damage the sensor and cause it to leak electrolyte

| Service the analyzer, check the power source, and THEN replace the sensor

Introduce span gas to determine if the sensor responds.

If successful calibrate the analyzer and re-some sampling

If not successful, inspect for electrolyte leakage, check and clean the contacts in the upper section of the sensor housing, flow a little warm water followed by air, or clean the sample through the analyzer for 2-3 hours to push the electrolyte through the sample system and THEN replace the sensor

Warranty

The design and manufacture of Analytical Industries Inc. oxygen analyzers 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. Before 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 by the Owner’s Manual, the units will provide many years of reliable service.

Coverage
Under normal operating conditions, the analyzers and sensors are warranted to be free of defects in materials and workman for the period specified by the most recent ID 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. Analytical Industries Inc. reserves the right in its sole discretion to invalidate this warranty if the serial number does not appear on the analyzer.
If your Analytical Industries Inc. analyzer and/or oxygen sensor is determined to be defective concerning 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 pur-chase, we may use new or reconditioned replacement parts. If we choose to replace your Analytical Industries 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
Analytical Industries Inc. will not pay for: loss of time; inconvenience; loss of use of your Analytical Industries Inc. analyzer or property damage caused by your Analytical Industries Inc. analyzer or its failure to work; any special, incidental, or consequential damages; or any damage 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 follow the Owner’s Manual. Some states 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 the 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 provided with the analyzer; fire, flood, or acts of God; or another failure to follow the Owner’s Manual.

S ervice
Call Analytical Industries Inc. at 909-392-6900 (or e-mail info@aii1.com) between:

  • 7:30 AM and 5:00 PM PST . . . Monday thru Thursday
  • 8:00 AM and 12:00 PM PST . . . 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 your analyzer, postage prepaid to:

  • Analytical Industries Inc.
  • 2855 Metropolitan Place
  • Pomona, Ca 91767 USA

Be sure to pack the analyzer securely. Include your name, address, telephone number, and a description of the operat-ing problem. After repairing or, at our option, replacing your Analytical Industries Inc. analyzer, we will ship it to you at no cost for parts and labor.

Safety Data Sheet

GPR Series Oxygen Sensors

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XLT Series Oxygen Sensors

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Specifications

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Appendix A

Regulations regarding equipment certified for use in hazardous areas require electrical connections to be protected by conduit and/or cable gland entry. Analytical Industries Inc. recognizes the need for the safe operation of this analyzer and strongly recommends the user adhere to all local safety-related directives during installation and operation.

Warning: The accessories used for cable gland entry, size 3/4”-14 NPT-M, must be covered by a separate certificate per the standards:

  • EN 60079-14:2014; IEC 60079-14:2013
  • EN 60079-17:2014; IEC 60079-17:2013

They must be suitable to be used with the enclosure and the type of hazardous location:

  • II 2 G
  • Ex db IIB or IIB+H2 T6 Gb

Electrical connections require approved explosion-proof sealing fittings and packing around wires and cables coming into or going out of the enclosure. Conduit seals and fittings must be certified “Ex d” components per EN60079-1 whose design and installation comply with ATEX standards for hazardous locations

Warning: Sealing fittings must be installed within 18″ of this enclosure for IIB + H2 locations.

All unused openings must be closed with a Killark CUP, CUPX, PLUG, GO-8177 series close=up plug or an Ex d certified close-up plug or sealing plug.

Explosion Proof Packing Fiber (non-asbestos)
For use as packing at the hub of sealing fittings. Use only ATEX-approved packing fiber.

info: These instructions are supplied in good faith from information that we believe to be reliable. However, since users and not Analytical Industries Inc. control the application, installation, and operation of our products, users therefore assume all associated risk and liability.
Warning: Contact and/or exposure may cause skin, lung, or eye irritation. Use gloves and long-sleeve coveralls to protect the skin. Use a mask or respirator to prevent inhalation or eye contact during application.

Directions

  1. To prevent leakage of the liquid cement, tamp packing fiber between and around conductors where they enter the fitting
  2. Ensure conductors DO NOT contact each other or the fitting wall.
  3. Leave enough space inside the fitting – space/ length equivalent to the inside diameter of the conduit but not less than 5/8”.

Explosion Proof Sealing Cement

Directions

  1. After tamping packing fiber between and around conductors, prepare the sealing resin.

  2. Use only ATEX-approved sealant.

  3. Prepare the sealant by mixing the resin catalyzing agent as recommended by the manufacturer.

  4. Apply the resin as recommended by the manufacturer.
    info: The following sealant for sealing fittings is ATEX-approved.

    • ELFIT RESIN (Part A) CRV420
    • ELFIT CATHALIZING AGENT (Part B) CRV420H72
  5. Mixture ratio: 100 grams Part A to 25 grams Part B

  6. Blthemmixtureture to obtain a homogeneous compound.

  7. Immediately fill the sealing connection.

  8. Cure 72 hours for the mixture to set.

Warning: Consult manufacturer instructions for complete details related to mixing two components and pouring the resulting resin into the sealing fittings.
Engage at least five threads on all fill plugs.

ProcessSensing.com

FAQ

  • Q: How often should I calibrate the oxygen analyzer?
    • A: It is recommended to calibrate the analyzer periodically based on your specific usage and environmental conditions. Regular calibration ensures accurate measurements.
  • Q: Can I use the analyzer in hazardous areas?
    • A: Yes, the GPR-x8 Oxygen Analyzers are explosion-proof and suitable for hazardous areas. Follow all safety guidelines provided in the manual for safe operation.

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