Analytical Industries GPR-35 User Manual

Advanced Instruments Inc..

GPR-35

Oxygen Analyzer

Ambient Area Monitoring

Owner’s Manual

2855 Metropolitan Place, Pomona, CA 91767 USA ♦ Tel: [phone], Fax: [phone], e-mail: [e-mail], www.aii1.com

Table of Contents

Introduction

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Quality Control Certification
Safety
Features & Specifications
Operation
Maintenance
Spare Parts
Troubleshooting
Warranty
Material Safety Data Sheet

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3
4
5
6

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8
9

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1 Introduction

Your new oxygen analyzer incorporates an advanced electrochemical sensor specific to oxygen along with state-of-the-art
electronics designed to give you years of reliable precise oxygen measurements in variety of industrial oxygen applications. To
obtain maximum performance from your new oxygen analyzer, 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 analyzer for
superior performance and minimal cost of ownership. This analyzer 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 analyzer is your assurance that we stand behind every analyzer sold.

The serial number of this analyzer may be found on the inside the analyzer. 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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2 Quality Control Certification

Date: Customer: Order No.: Pass

Model: GPR-35 Oxygen Analyzer Ambient Area Monitoring S/N _______________
Sensor: ( ) GPR-11-32-RTS Oxygen Sensor

( ) XLT-11-24-RTS Oxygen Sensor
( ) Remote above sensor -4R suffix S/N _______________

Approvals: CSA/NRTL and CE
Accessories: Owner’s Manual

A-2344 Calibration Flow Through Adapter

Configuration: A-1113-C PCB Assembly Main/Display

A-1114-C PCB Assembly Power Supply
Range: 0-25%

Low and Low, Low Alarms: 20.0% CAUTION, 19.5% DANGER
Test – AC Power Calibrates at 20.9% oxygen in ambient air with adequate span
CAUTION/LOW O2 Alarms: LED green–safe/red–alarm, relay contact
DANGER/LOW, LOW O2 Alarms: LED green–safe/red–alarm, relay contact
Alarm relays activate/deactivate with changes in O2 concentration
LED indicators: AC FAIL-red, LOW BATT-red
Sensor failure 5V +0.5V
Power failure relay alarm contacts
Analog signal output 0-1V
Test – Battery No interruption in operation when disconnecting AC power
Calibrates at 20.9% oxygen in ambient air with adequate span
CAUTION/LOW O2 Alarms: LED green–safe/red–alarm, relay contact
DANGER/LOW, LOW O2 Alarms: LED green–safe/red–alarm, relay contact
Alarm relays activate/deactivate with changes in O2 concentration
LED indicators: AC FAIL-red, LOW BATT-red
Final Overall inspection for physical defects

Options:

Notes:

( ) High, Low Alarms: HIGH O2 23%, LOW O2 19.5%
( ) 4-20mA isolated signal output (0-1VDC negative ground standard)
( ) A-2501 Integral sampling pump

( ) Integral audible alarm
( ) Remote sensor: A-1114C-R PCB Assy; components see following page

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3 General Safety & Installation

Safety

This section summarizes the basic precautions applicable to all analyzers. Additional precautions specific to individual analyzer
are contained in the following sections of this manual. To operate the analyzer 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.

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 analyzer read the instructions.
Retain Instructions: The safety precautions and operating instructions found in the Owner’s Manual should be retained for

future reference.
Heed Warnings Follow Instructions: Follow all warnings on the analyzer, accessories (if any) and in this Owner’s Manual.

Observe all precautions and operating instructions. Failure to do so may result in personal injury or damage to the analyzer.

Heat: Situate and store the analyzer away from 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 and knobs. Before moving your analyzer be sure to disconnect the

wiring/power cord and any cables connected to the output terminals located on the analyzer.

Cautions

Pollution degree, 2
Installation category, II
Altitude, 3000m
Humidity, non-condensing up to 95%
Suitable for indoor use only
Operating temperature range 5 to 45⁰C
Power supply fluctuations are not to exceed +/- 10% of the nominal voltage specified in section 4.

Maintenance

Serviceability: Except for replacing the oxygen sensor, there are no parts inside the analyzer 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 this Owner’s Manual. Avoid contact with any liquid or crystal
type powder in or around the sensor or sensor housing, as either could be a form of electrolyte. Leaking sensors should be
disposed of in accordance with local regulations.

Troubleshooting: Consult the guidelines in section 8 for advice on the common operating errors before concluding that your
analyzer is faulty. Do not attempt to service the analyzer beyond those means described in this Owner’s Manual. Do not attempt
to make repairs by yourself as this will void the warranty, as detailed by section 9, and may result in electrical shock, injury or
damage. All other servicing should be referred to qualified service personnel.

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Cleaning: The analyzer 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: Disconnect the power when the analyzer is left unused for a long period of time.

Recommended Safety Checklist

The user is responsible for determining whether the unit will assure safety in his particular application and establishing safety
precautions. It is strongly recommended the operator understands, tests the operation of this oxygen deficiency alarm and
develop a safety checklist related to the use of this unit. The checklist should include but not be limited to:

1. Limiting access to unit to authorized and trained personnel.

2. Install a switch or circuit breaker near the equipment to disconnect the AC power during service intervals to prevent electric
shock and possible damage to the equipment.

3. Follow the instruction for Electrical Connections and use a minimum of 18 AWG cable for AC power connections.

4. Test and calibration procedures are instituted and routinely followed.

5. Users understand the operation and functions of the unit.

6. The user consult a safety expert in the selecting the most appropriate location to install the unit and providing all necessary
warning notices.

7. Source of AC power is reliable and adequate. In the event AC power is interrupted, users should not depend on the battery
backup but correct the problem as quickly as possible.

8. Assure the battery is in good operating condition by periodically disconnecting the AC power and operating the unit for
several hours under battery power verifying the various functions of the unit are operational and alarm indicators operate
as intended.

9. Any sampling considerations are identified and resolved.

10. External environmental considerations are identified and resolved.

Installation

Gas Sample Stream: Ensure the gas stream composition of the application is consistent with the specifications and review the
application conditions before initiating the installation. Consult the factory to ensure the sample is suitable for analysis. Note: In
natural gas applications such as extraction and transmission, a low voltage current is applied to the pipeline itself to inhibit
corrosion. As a result, electronic devices can be affected unless adequately grounded.

Contaminant Gases: A gas scrubber and flow indicator with integral metering valve are required upstream of the of the
analyzer to remove interfering gases such as oxides of sulfur and nitrogen or hydrogen sulfide that can produce false readings,
reduce the expected life of the sensor and void the sensor warranty if not identified at time of order placement. Installation of a
suitable scrubber is required to remove the contaminant from the sample gas to prevent erroneous analysis readings and
damage to the sensor or optional components. Consult the factory for recommendations concerning the proper selection and
installation of components.

Expected Sensor Life: With reference to the publish specification located as the last page of this manual, the expected life of
all oxygen sensors is predicated on oxygen concentration (< 1000 ppm or air), temperature (77°F/25°C) and pressure (1
atmosphere) in “normal” applications. Deviations are outside the specifications and will affect the life of the sensor. As a rule of
thumb sensor life is inversely proportional to changes in the parameters.

Accuracy & Calibration: Refer to section 5 Operation.
Materials: Assemble the necessary zero, purge and span gases and optional components such as valves, coalescing or

particulate filters, and, pumps as dictated by the application; stainless steel tubing is essential for maintaining the integrity of
the gas stream for ppm and percentage range (above or below ambient air) analysis; hardware for mounting.

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 1,800ºF to ambient. The
maximum operating temperature is 45º C on an intermittent basis unless the user is willing to accept a reduction in expected
sensor life – refer to analyzer specification - where expected sensor life is specified at an oxygen concentration less than 1000
ppm oxygen for ppm analyzers and air (20.9% oxygen) for percent analyzers, but in all instances at 25°C and 1 atmosphere of
pressure. Expected sensor varies inversely with changes in these parameters.

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Pressure & Flow

All electrochemical oxygen sensors respond to partial pressure changes in oxygen. The sensors are equally capable of analyzing
the oxygen content of a flowing sample gas stream or monitoring the oxygen concentration in ambient air (such as a confined
space such in a control room or an open area such as a landfill or bio-pond).

The GPR-35 designed for in-situ ambient or area monitoring and has no sample system
because the sensor is intended to be exposed directly to the surrounding ambient atmosphere
which it is sampling and to operate at atmospheric pressure, however, slightly positive
pressure has minimal effect on accuracy.

A certified span gas is recommended for calibration purposes, part number A-2344 Flow
Through Adapter is supplied with the GPR-35 and provides: a hose connection for piping the
calibration gas (see positive pressure see below) to the sensor, an o-ring seal to isolate the
sensor from the atmosphere being monitored and outlet to vent the calibration gas.

Further, applications situations may dictate that the sample be transported from a semi-sealed
area to a safe area where the analyzer is located. In these cases the analyzer can be readily adapted to include optional pumps,
tubing and connection fittings. Users interested in adding their own sample conditioning system should consult the factory.

Analyzers designed for flowing samples under positive pressure or pump vacuum (for samples at atmospheric or slightly
negative atmospheres) that does not exceed 14” water column are equipped with bulkhead tube fitting connections on the side
of the unit (unless otherwise indicated, either fitting can serve as inlet or vent) and are intended to operate at positive pressure
regulated to between 5-30 psig although their particular rating is considerably higher. In positive pressure applications the vent
pressure must be less than the inlet, preferably atmospheric.

Flow rates of 1-5 SCFH cause no appreciable change in the oxygen reading. However, flow rates above 5 SCFH generate
backpressure and erroneous oxygen readings because the diameter of the integral tubing cannot evacuate the sample gas at
the higher flow rate. The direction the sample gas flows is not important, thus either tube fitting can serve as the inlet or vent –
just not simultaneously. A flow indicator with an integral metering valve upstream of the sensor is provided as a means of
controlling the flow rate of the sample gas. A flow rate of 2 SCFH or 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 vacuum on the sensor and may damage the sensor (voiding the
sensor warranty). To avoid generating a vacuum on the sensor (as described above) during operation, always select and install
the vent fitting first and remove the vent fitting last.

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 necessary, a pressure regulator (with a metallic
diaphragm is recommended for optimum accuracy, the use of diaphragms of more permeable materials may result in erroneous
readings) upstream of the flow control valve should be used to regulate the inlet pressure between 5-30 psig.

Application Pressure - Atmospheric or Slightly Negative: An optional external sampling pump should be positioned
upstream of the sensor to draw the sample from the process, introduce it at a predetermined flow rate of 2 SCFH to the sensor
and out to atmosphere. A flow meter is generally not necessary to obtain the recommended flow rate with most sampling
pumps.

Caution: If the analyzer is equipped with an optional flow indicator with integral metering valve or a metering flow control
valve upstream of the sensor - open the metering valve completely 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.

Recommendations to avoid erroneous oxygen readings and damaging the sensor:

¾ 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 (thus voiding
the sensor warranty).

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¾ Assure there are no restrictions in the sample or vent lines
¾ Avoid drawing a vacuum that exceeds 14” of water column pressure – unless done gradually
¾ Avoid excessive flow rates above 5 SCFH which generate backpressure on the sensor.
¾ Avoid sudden releases of backpressure that can severely damage the sensor.
¾ Avoid the collection of liquids or particulates on the sensor, they block the diffusion of

oxygen into the sensor - wipe away.

¾ If the analyzer is equipped with an optional integral sampling pump (positioned

downstream of the sensor) and a flow control metering valve (positioned upstream of the
sensor), completely open the flow control metering valve to avoid drawing a vacuum on
the sensor and placing an undue burden on the pump.

¾ Calibrate ambient area monitors with a certified span gas.
¾ Avoid calibration of ambient area monitors with the surrounding atmosphere unless

assured the oxygen content is 20.9%.

¾ Optionally, to confirm the span gas calibration or air calibration of the GPR-35, the user can

use an inexpensive battery powered hand held analyzer (such as the AII-3000A pictured at
right) that is easily air calibrated in a “safe remote area” and carried to the area being
monitored by the GPR-35 where readings can be compared.

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 optional components. Moisture and/or particulates do not necessarily
damage the sensor, however, collection 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 when in fact the problem is easily
remedied by blowing on the front of the sensor. Consult the factory for recommendations concerning the proper selection and
installation of components.

Moisture and/or particulates generally can be removed from the sensor by opening the sensor housing and either blowing on
the the sensing surface or gently wiping or brushing the sensing surface with damp cloth. Caution: Minimize the exposure of
ppm sensors to air during this cleaning process. Air calibration followed by purging with zero or a gas with a low ppm oxygen
concentration is recommended following the cleaning process. Moisture and/or particulates generally can be removed from the
sample system by flowing the purge gas through the analyzer at a flow rate of 4.5-5 SCFH for an hour.

Mounting: The analyzer is approved for indoor use, outdoor use requires optional enclosures, consult factory. Mount as
recommended by the manufacturer.

Gas Connections: Analyzers designed for in-situ ambient or area monitoring have no sample system because the sensor is
intended to be exposed directly to the surrounding ambient atmosphere which it is sampling and to operate at atmospheric
pressure, however, slightly positive pressure has minimal effect on accuracy. Further, applications situations may dictate that
the sample be transported from a semi-sealed area to a safe area where the analyzer is located. In these cases the analyzer can
be readily adapted to include optional pumps, tubing and connection fittings.

Power: Supply power to the analyzer only as rated by the specification or markings on the analyzer enclosure. The wiring that
connects the analyzer to the power source should be installed in accordance with recognized electrical standards. Ensure that is
properly grounded and meets the requirements for area classification. Never yank wiring to remove it from a terminal
connection. AC powered analog analyzers consume 5 watts.

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4 Features & Specifications

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5 Operations

Principle of Operation

The GPR-35 oxygen analyzer incorporates a variety of percentage range advanced galvanic fuel cell type sensors. In compliance
with OSHA specifications, the standard unit is configured with two oxygen alarms which have been set by the factory to
energize audio and visual alarms when oxygen levels fall below CAUTION (20.0% O
general purpose NEMA 4 rated wall mount enclosure.

Optional equipment includes a remote sensor, 19.5% low and 23.0% high alarm configuration, an integral sampling pump, 4­20mA isolated signal output, integral audible alarm or external audible and/or visual alarms.

The GPR-35 is CE certified and manufactured along with the sensors under a Quality Assurance System certified by an
independent agency to ISO 9001:2000 standards.

Advanced Galvanic Sensor Technology

The sensors function on the same principle and are specific for oxygen. They measure the partial pressure of oxygen from low
ppm to 100% levels in inert gases, gaseous hydrocarbons, helium, hydrogen, mixed gases, acid gas streams and ambient air.
Oxygen, the fuel for this electrochemical transducer, diffusing into the sensor reacts chemically at the sensing electrode to
produce an electrical current output proportional to the oxygen concentration in the gas phase. The sensor’s signal output is
linear over all ranges and remains virtually constant over its useful life. The sensor requires no maintenance and is easily and
safely replaced at the end of its useful life.

Proprietary advancements in design and chemistry add significant advantages to an extremely versatile oxygen sensing
technology. Sensors for low ppm analysis recover from air to ppm levels in minutes, exhibit longer life, extended operating
range of -20°C to 50°C, excellent compatibility with CO
significant advantage over the competition.

The expected life of our new generation of percentage range sensors now range to five and ten years with faster response
times and greater stability. Other significant developments involve the first galvanic oxygen sensor capability of continuous
oxygen purity measurements and expanding the operating temperature range from -40°C to 50°C.

and acid gases (XLT series) and reliable quality giving them a

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) and DANGER (19.5% O2) housed in a

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