Analytical Industries Inc (AII) GPR-3500 MO Operating Manual

Technical Specifications *

Accuracy:

Analysis:

Application: Intermittent monitoring of oxygen levels up to 100% O2

Area Classification: General purpose

Calibration:

Connections: 1/8" compression tube fittings

Controls:

Display:

Enclosure: Painted aluminum, 4 x 9 x 3", 8 lbs.

Flow Sensitivity: Not flow sensitive, 1-2 SCFH recommended

LED Indicators: LOW BATT (72 hr. warning); CHARGE mode

< 2% of FS range under constant conditions, e.g.
constant temperature, flow rate and ambient pressure

0-100% FS range

Max interval—3 months. Use certified span gas with 97­100% O2 (balance N2). To comply with FDA requirements
for medical grade O2, zero calibrate with not less than

99.9% N2 (balance O2) or span calibrate with not less
than 99.99% O2 (balance N2). For Oxygen 93
(transfilling), calibrate with 93% +0.1% O2 (balance N2).

Water resistant keypad; menu driven range selection,
calibration and system functions

Graphical LCD 2.75” x 1.375”; resolution 0.1%;
displays real time ambient temperature and pressure

GPR-3500 MO

Portable Oxygen Purity

Linearity: ±1% of full scale

Pressure:

Power: Rechargeable battery, 60 day cycle

Response Time: 90% of final reading in 13 seconds

Sample System: Flow indicator & control valve

Sensitivity: < 0.5% of FS range

Sensor Model:

Sensor Life:

Signal Output: 0-1V FS

Operating Range: 5ºC to 45ºC

Warranty: 12 months analyzer; 12 months sensor

Wetted Parts: Stainless steel

Optional Equipment

Sample conditioning system - Contact factory.

Inlet - regulate to 5-30 psig to deliver 1-2 SCFH flow;
vent - atmospheric

GPR-11-120-RTS

24 months in 100% O2 at 25ºC and 1 atm

Analyzer

Advanced Galvanic Sensor Technology

Proprietary Long Life Sensor

24 Months @ 100% Oxygen

Sensitivity 0.5% Full Scale
Rechargeable Battery Power
Barometric Pressure Compensated
Unaffected by Vibration & Motion
Designed for Industrial Use

ISO 9001:2008 Certified

INTERTEK Certificate No. 485

* Subject to change without notice

2855 Metropolitan Place, Pomona, CA 91767 USA ♦ Tel: [phone], Fax: [phone], www.aii1.com, e-mail: [e-mail] Rev 10/15

Advanced Instruments Inc.

GPR-3500 MO

Portable Oxygen Purity Analyzer

Owner’s Manual

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
Quality Control Certification
General Safety & Installation
Features & Specifications
Operation
Maintenance
Spare Parts
Troubleshooting
Warranty
Material Safety Data Sheets
Correlate LCD to Signal Output Appendix

Advanced Instruments Inc.

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3
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5
6

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8
9

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1 Introduction

Your new oxygen portable oxygen purity analyzer incorporates an advanced electrochemical sensor specific to oxygen along with state­of-the-art digital 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 portable oxygen purity 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 portable oxygen purity
analyzer for superior performance and minimal cost of ownership. This portable oxygen purity 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 portable oxygen purity analyzer is your assurance that we stand behind every portable
oxygen purity analyzer sold.

The serial number of this portable oxygen purity analyzer may be found on the inside the portable oxygen purity 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: _______________________

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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.

2 Quality Control Certification

Date: Customer: Order No.: Pass
Model:

Sensor:
Accessories:

Configuration:

Test:

Final:

Options:
Notes:

GPR-3500MO Oxygen Purity Transmitter S/N ___________________
GPR-11-120-4 Oxygen Sensor S/N ___________________

Owner’s Manual
A-2221 Sensor Flow Housing 1/8” FNPT (integral)

A-1151-B3 PCB Assembly Software Ver. _________
Range(s): 0-100%
NEMA 4 rated wall mount enclosure

Default zero (without sensor)
Default span @ 20uA
No interruption in operation when connecting AC charger/adapter
Calibrates at 20.9% oxygen in ambient air and 100% oxygen with adequate span
Analog signal output 0-1V (0-100% oxygen)
Baseline drift on zero gas < ± 2% FS over 24 hour period
Noise level < ± 1.0% FS
Span adjustment within 10-50% FS
Overall inspection for physical defects

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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.

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.

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.

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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.

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 following is applicable to analyzers equipped with fuel cell type
oxygen sensors. With respect to analyzers equipped with Pico-Ion UHP and MS oxygen sensors, refer to the analyzer’s specifications.

Analyzers designed for in-situ ambient or area monitoring have no real inlet and vent pressure because the sensor is exposed directly
to the sample gas and intended to operate at atmospheric pressure, however, slightly positive pressure has minimal effect on accuracy.

Inlet Pressure: 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. Caution: If the analyzer is equipped with an
optional H2S scrubber, inlet pressure must not exceed 30 psig.

Outlet Pressure: In positive pressure applications the vent pressure must be less than the inlet, preferably atmospheric.
Sample systems and flowing gas samples are generally required for applications involving oxygen measurements at a pressure other

than ambient air. In these situations, the use of stainless steel tubing and fittings is critical to maintaining the integrity of the gas
stream to be sampled and the inlet pressure must always be higher than the pressure at the outlet vent which is normally at
atmospheric pressure. Flow Through Configuration: The sensor is exposed to sample gas that must flow or be drawn through metal
tubing inside the analyzer. The internal sample system includes 1/8” compression inlet and vent fittings, a stainless steel sensor
housing with an o-ring seal to prevent the leakage of air and stainless steel tubing.

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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 recommended 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. To reduce the possibility of leakage for low ppm measurements, position a
metering needle valve upstream of the sensor to control the flow rate and position a flow indicator downstream of the sensor. 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.

Caution: If the analyzer is equipped with a H2S scrubber as part of an optional sample conditioning system, inlet pressure must not
exceed 30 psig.

Application Pressure - Atmospheric or Slightly Negative: For accurate ppm range oxygen measurements, an optional external
sampling pump should be positioned downstream of the sensor to draw the sample from the process, by the sensor and out to
atmosphere. A flow meter is generally not necessary to obtain the recommended flow rate with most sampling pumps.

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).

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
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.

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.

- wipe away.

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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: Inlet and outlet vent gas lines for ppm analysis require 1/8” or ¼” stainless steel compression fittings; hard plastic
tubing with a low permeability factor can be used percentage range measurements.

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, digital analyzers 50 watts without optional heaters. Optional 110V and 220V heaters AC
powered heaters consume an additional 100-150 watts; DC powered digital analyzers consume 30 watts, 40 watts with the optional DC
powered heater.

4 Features & Specifications

See last page, this page left blank intentionally.

5 Operation

Principle of Operation

The GPR-3500MO portable oxygen purity analyzer incorporates a unique advanced electrochemical galvanic fuel cell type sensor. The
portable oxygen purity analyzer is configured in an intrinsically safe design and meets the intrinsic safety standards required for use in
Class 1, Division 1, Groups A, B, C, D hazardous areas.

Advanced Galvanic Sensor Technology

The sensors 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 and reliable quality. 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. Another
significant development involves expanding the operating temperature range for percentage range sensors from -30°C to 50°C.

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The sensor employed by the GPR-3500MO is but one part of the proprietary advancements in sensor technology. It is the only
electrochemical galvanic sensor available that is capable measuring 100% oxygen on a continuous 24/7 basis.

Electronics

The signal generated by the sensor is processed by state of the art low power micro-processor based digital circuitry. The first stage
amplifies the signal. The second stage eliminates the low frequency noise. The third stage employs a high frequency filter and
compensates for signal output variations caused by ambient temperature changes. The result is a very stable signal. Sample oxygen is
analyzed very accurately. Response time of 90% of full scale is less than 10 seconds (actual experience may vary due to the integrity
of sample line connections, dead volume and flow rate selected) on all ranges under ambient monitoring conditions. Sensitivity is
typically 0.5% of full scale low range. Oxygen readings may be recorded by an external device via the 0-1V signal output jack.

Power is supplied by an integral rechargeable lead acid battery which provides enough power to operate the analyzer continuously for
approximately 60 days. Expect 8-10 hours service from a single battery charge when using the pump on a regular basis. An LED
located on the front panel provides a blinking 72 hour warning to recharge the battery. A 9VAC adapter (positive pole located on the
inside of the female connector) can be used to recharge the battery from a convenience outlet. The analyzer is designed to be fully
operational during the 8-10 hour charging cycle which is indicated by a second continuously lit LED.

Sample System

The GPR-3500MO is supplied with panel mounted flow meter for maximum portability. Users interested in adding their own sample
conditioning system should consult the factory. Advanced Instruments Inc. offers a full line of sample handling, conditioning and
expertise to meet your application requirements. Contact us at 909-392-6900 or e-mail us at [e-mail]

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Accuracy & Calibration

Single Point Calibration: As previously described the
galvanic oxygen sensor generates an electrical current
proportional to the oxygen concentration in the sample gas.

Absolute Zero: In the absence of oxygen the sensor exhibits
an absolute zero, e.g. the sensor does not generate a current
output in the absence of oxygen. Given these linearity and
absolute zero properties, single point calibration is possible.

Pressure: Because sensors are sensitive to the partial pressure
of oxygen in the sample gas their output is a function of the
number of molecules of oxygen 'per unit volume'. Readouts in
percent are permissible only when the total pressure of the
sample gas being analyzed remains constant. The pressure of
the sample gas and that of the calibration gas(es) must be the
same (reality < 1-2 psi).

Temperature: The rate oxygen molecules diffuse into the sensor is controlled by a Teflon membrane otherwise known as an 'oxygen
diffusion limiting barrier' and all diffusion processes are temperature sensitive, the fact the sensor's electrical output will vary with
temperature is normal. This variation is relatively constant 2.5% per ºC.

A temperature compensation circuit employing a thermistor offsets this effect with an accuracy of better than +
Operating Range of the analyzer) and generates an output function that is independent of temperature. There is no error if the
calibration and sampling are performed at the same temperature or if the measurement is made immediately after calibration. Lastly,
small temperature variations of 10-15º produce < 1% error.

Accuracy:

producing 'percent of reading errors', illustrated by Graph A below, such as +5% temperature compensation circuit, tolerances of
range resistors and the 'play' in the potentiometer used to make span adjustments and 2) those producing 'percent of full scale errors',
illustrated by Graph B, such as +
fact that other errors are 'spanned out' during calibration. Graph C illustrates these 'worse case' specifications that are typically used to
develop an transmitter's overall accuracy statement of < 1% of full scale at constant temperature or < 5% over the operating
temperature range. QC testing is typically < 0.5% prior to shipment.

Example: As illustrated by Graph A any error, play in the multi-turn span pot or the temperature compensation circuit, during a span
adjustment at 20.9% (air) of full scale range would be multiplied by a factor of 4.78 (100/20.9) if used for measurements of 95-100%
oxygen concentrations. Conversely, an error during a span adjustment at 100% of full scale range is reduced proportionately for
measurements of lower oxygen concentrations.

In light of the above parameters, the overall accuracy of an analyzer is affected by two types of errors: 1) those

1-2% linearity errors in readout devices, which are really minimal due to today's technology and the

5% (over the entire

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Zero Calibration

In theory
free sample gas. In reality

¾ Contamination or quality of the zero gas
¾ Minor leakage in the sample line connections
¾ Residual oxygen dissolved in the sensor’s electrolyte
¾ Tolerances of the electronic components

The Zero Offset capability of the analyzer is limited to 50% of lowest most sensitive range available with the analyzer.
As part of our Quality Control Certification process, the zero capability of every ppm analyzer is qualified prior to shipment. However,

because the factory sample system conditions differ from that of the user, no ZERO OFFSET adjustment is made to analyzer by the
factory

Recommendations:

¾ Zero calibration is recommended only

¾ Determining the true Zero Offset requires approximately 24 hours to assure the galvanic fuel cell sensor has consumed the oxygen

¾ Zero calibration is not practical and not recommended for portable analyzers or measurements on higher ranges. However,

¾ Zero calibration should precede span calibration.
¾ Initiate the DEFAULT ZERO and DEFAULT SPAN procedures before performing either a ZERO or SPAN CALIBRATION.
¾ Caution: Prematurely initiating the ZERO CALIBRATION function can result in negative readings near zero.
¾ Once the zero offset adjustment is made, zero calibration is normally not required again until the sample system connections are

, the galvanic fuel cell type oxygen has an absolute zero meaning it produces no signal output when exposed to an oxygen

, expect the analyzer to generate an oxygen reading when sampling a zero gas due to:

for online analyzers performing continuous analysis below 5% of the lowest most sensitive
range available with a ppm analyzer, e.g. analysis below 0.05 ppm on the 0-1 ppm range, 0.5 ppm on the 10 ppm range, or
below 0.1% (1000 ppm) with a percent analyzer.

that has dissolved into the electrolyte inside the sensor while exposed to air or percentage levels of oxygen. Allow the analyzer to
stabilize with flowing zero gas as evidenced by a stable reading or horizontal trend on an external recording device. For optimum
accuracy, utilize as much of the actual sample system as possible.

satisfying these users that the zero offset is acceptable for their application without the 24 hour wait can be accomplished by
introducing a zero gas (or sample gas with a low ppm oxygen concentration) to the analyzer. Unless the zero gas is contaminated
or there is a significant leak in the sample connections, the analyzer should read less than 100 ppm oxygen within 10 minutes after
being placed on zero gas thereby indicating it is operating normally.

modified, or, when installing a new oxygen sensor.

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Span Calibration

Span Calibration involves adjusting the transmitter electronics to the sensor’s signal output at a given oxygen standard. Maximum drift
from calibration temperature is approximately 0.11% of reading per °C. The frequency of calibration varies with the application
conditions, the degree of accuracy required by the application and the quality requirements of the user. However, the interval between
span calibrations should not exceed three (3) months.

Note: Regardless of the oxygen concentration of the standard used, the span calibration process takes approximately 10 minutes,
however, the time required to bring the analyzer back on-line can vary depending on a combination of factors and assume exposure to
a zero/purge/sample gas** with an oxygen content below the stated thresholds immediately after span calibration:

* Refer to analyzer specifications for comparable data on the Pico-Ion UHP and MS oxygen sensors.
Recommendations General:

¾ The interval between span calibrations should not exceed three (3) months.
¾ Initiate the DEFAULT ZERO and DEFAULT SPAN procedures before performing either a ZERO or SPAN CALIBRATION.
¾ Caution: Prematurely initiating the SPAN CALIBRATION function before the analyzer reading has stabilized can result in erroneous

readings. This is especially true when installing a new sensor that must adjust to the difference in oxygen concentrations. It should
take about 2 minutes for the sensor to equilibrate in ambient air from storage packaging.

¾ Always calibrate at the same temperature and pressure of the sample gas stream.
¾ For 'optimum calibration accuracy' calibrate with a span gas approximating 80% of the full scale range one or a higher range than

the full scale range of interest (normal use) to achieve the effect of “narrowing the error” by moving downscale as illustrated by
Graph A in the Accuracy & Calibration section.

¾ Calibrating with a span gas approximating 5-10% of the full scale range near the expected oxygen concentration of the sample

gas is acceptable but less accurate than ‘optimum calibration accuracy’ method recommended – the method usually depends on
the gas available.

¾ Calibrating at the same 5-10% of the full scale range for measurements at the higher end of the range (example: calibrating an

Oxygen Purity Analyzer in air at 20.9% oxygen with the intention of measuring oxygen levels of 50-100%) results in the effect of
“expanding the error” by moving upscale as illustrated by Graph A and Example 1 in the Accuracy & Calibration section above and
is not recommended. Of course the user can always elect at his discretion to accept an accuracy error of +
if no other span gas is available.

Recommendations Air Calibration:

¾ Do not calibrate an analyzer employing the Pico-Ion UHP or MS sensor, or, an oxygen purity sensor with air.
¾ The inherent linearity of the galvanic fuel cell type oxygen sensor enables the user to calibrate any analyzer with ambient air

(20.9% oxygen) and operate the analyzer within the stated accuracy spec on the lowest most sensitive range available with the
analyzer – it is not necessary to recalibrate the analyzer with span gas containing a lower oxygen concentration.

¾ When installing or replacing a ppm or percent oxygen sensor.
¾ To verify the oxygen content of a certified span gas.

2-3% of full scale range

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¾ When certified span gas is not available to calibrate a ppm analyzer (immediately following air calibration reintroduce a gas with a

low oxygen concentration to expedite the return to ppm level measurements as described above **).

Mounting the Analyzer

Normally mounting a portable analyzer is not a consideration. However, the GPR-3500 analyzer can operate continuously when
connected to AC power using the appropriate charging adapter. The analyzer enclosure is cast with four (4) holes in the bottom section
specifically intended for mounting to any flat vertical surface.

Gas Connections

The GPR-3500MO with its standard flow through configuration is designed for positive pressure samples and requires connections for
incoming sample and outgoing vent lines. Zero and span inlet ports are offered as part of the optional sample systems. The user is
responsible for calibration gases and the required components, see below.

With the pressure regulated to between 5-30 psig, 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. A flow indicator with an integral metering valve upstream of the sensor is
recommended 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).

Procedure:

1. Caution: Do not change the factory setting until instructed to do in this manual.

2. Designate one of the bulkhead tube fittings as the VENT and the other SAMPLE.

3. Regulate the pressure as described in Pressure & Flow above.

4. Connect a 1/8” vent line to the compression fitting to be used for venting the sample.

5. Connect a 1/8” ZERO, SPAN or SAMPLE line to the fitting designated SAMPLE.

6. If equipped with optional fittings and/or sample system, connect the ZERO and SPAN gas lines.

7. Allow gas to flow through the portable oxygen purity analyzers and set the flow rate to 2 SCFH.

Output connection:

The analyzer provides a 0-1V full scale with negative ground signal output for external recording devices.

Procedure:

1. Connect the lead wires from the external recording device to the male phone plug supplied with analyzer. (Note: Connect the
positive lead to the center terminal of the male phone plug.)

2. Insert the male phone plug into the integral female OUTPUT jack located on the side of the enclosure.

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Installing the Oxygen Sensor

The GPR-3500MO portable oxygen purity analyzer is equipped with an integral oxygen sensor. It has
been tested and calibrated by the manufacturer prior to shipment and are fully operational from the
shipping container. However, when the application requires a remote sensor (external to the electronics
enclosure) or other special circumstances, the oxygen sensor will be packaged separately and must be
installed prior to operating the portable oxygen purity analyzer. If the sensor has not been installed at
the factory, it will be necessary to install the sensor in the field.

Caution: All portable oxygen purity analyzers must be calibrated once the installation has been
completed and periodically thereafter as described below. Do not change the factory settings until
instructed to do in this manual.

Caution: DO NOT open the oxygen sensor. The sensor contains a corrosive liquid electrolyte that could
be harmful if touched or ingested, refer to the Material Safety Data Sheet section. 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 manner similar to that of a common battery in
accordance with local regulations.

Procedure:

1. Remove the four (4) screws securing the top section of the enclosure, set them aside for reinstallation and remove the front cover.

2. Caution: Do not remove or discard the gasket from the enclosure. Failure to reinstall the gasket will void the NEMA 4 rating and
RFI protection.

3. Remove the oxygen sensor from the bag.

4. Screw the oxygen sensor into the sensor flow housing, equipped with elbows and tubing, finger tighten plus one half (1/2) turn to
ensure a good seal from the o-ring affixed to the sensor.

5. Remove the shorting device (looped wire) from the receptacle located at the rear of the sensor. Minimize the time the sensor is
exposed to ambient air.

6. Assure the keyway registration of the female plug on the cable and male receptacle on the sensor match up.

7. Push the female plug (including the knurled lock nut) molded to the cable into the male receptacle attached to the new sensor.

8. Screw the knurled lock nut attached the cable onto to the male connector attached to the sensor, tighten finger tight plus ¼ turn.

9. Replace the front cover of the portable oxygen purity analyzer and ensure that the gasket is replaced as well to maintain CE
approval and NEMA 4 rating.

10. Tighten the four (4) screws to secure the front cover.

11. Connect the gas lines, vent line first, as previously described.

12. Proceed to calibration.

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Span Gas Preparation

Caution: Do not contaminate the span gas cylinder when connecting the regulator. Bleed the air filled regulator (faster and more
reliable than simply flowing the span gas) before attempting the initial calibration of the instrument.

Medical grade oxygen:

The FDA requires the use of certified gases for zeroing and calibrating analyzers used in certifying medical grade oxygen. Advanced
Instruments Inc. recommends zeroing and calibrating the analyzer before each certification.

The analyzer zero gas must be a certified cylinder of nitrogen with a minimum purity of 99.9%. Once the analyzer has been zeroed
(described below), calibrate (described below) with a certified cylinder of oxygen with a minimum purity of 99.2%.

Non-medical grade oxygen applications:

In non-medical grade oxygen applications the analyzer does not require zeroing before every calibration. It is recommended the
analyzer be calibrated at least monthly. In most cases nitrogen zero gas of 99% minimum purity and a span gas of 95-100% oxygen
purity is sufficient.

Required components:

¾ Certified span gas cylinder with an oxygen concentration, balance nitrogen, approximating 80% of the full scale range above the

intended measuring range.

¾ Regulator to reduce pressure to between 5 and 30 psig.
¾ Flow meter to set the flow between 1-5 SCFH,
¾ 2 lengths of 1/8” dia. metal tubing measuring 4-6 ft. in length.
¾ Suitable fittings and 1/8” dia. metal tubing to connect the regulator to the flow meter inlet
¾ Suitable fitting and 1/8” dia. metal tubing to connect from the flow meter vent to tube fitting designated SAMPLE IN on the GPR-

1200.

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.

8. Set the pressure between 5-30 psig using the pressure regulator’s control knob.

9. Caution: Do not exceed the recommended flow rate. Excessive flow rate could cause the backpressure on the sensor and may
result in erroneous readings and permanent damage to the sensor.

Establishing Power to the Electronics

Establish power to the analyzer electronics by pushing the red ON/OFF key. The digital display
responds instantaneously. When power is applied, the analyzer performs several diagnostic
system status checks termed “START-UP TEST” as illustrated below.

The optional integral sampling pump is activated by a separate toggle switch located on the
front of the analyzer.

Note: In the unlikely event the LED warning indicator LOW BATT comes on when the
analyzer is turned on – proceed immediately to the section Battery Considerations at the end
of section 5 Operation.

Note: The GPR-3500MO is supplied with an adapter for recharging the batteries or operating
the analyzer continuously.

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Charging the battery requires a common 9VDC adapter (positive pole located inside the female connector) supplied with the analyzer
and a convenience outlet. The analyzer’s charging circuit accepts 9VDC from any standard AC 110V or 220V adapter (specified when
the order is placed). The electronic design enables the analyzer to remain fully operable during the 8-10 hour charging cycle.

When power is applied, the software performs several diagnostic system status checks termed “START-UP TEST” as illustrated below.

Note: The analyzer display defaults to the sampling mode when 30 seconds elapses without user interface.

START-UP TEST

ELECTRONICS – PASS
LOOP POWER – PASS
TEMP SENSOR – PASS
BAROMETRIC SENSOR – PASS

Menu Navigation

The four (4) pushbuttons located on the front of the portable oxygen purity analyzer operate the micro-processor:

1. Green ENTER (select)

2. Yellow UP ARROW

3. Yellow DOWN ARROW

4. Blue MENU (escape)

Main Menu

Access the MAIN MENU by pressing the MENU key:

93.3 %

AUTO SAMPLING

100% RANGE

24.5 C 100 KPA

MAIN MENU

AUTO SAMPLE

MANUAL SAMPLE
CALIBRATE

24.5 C 100 KPA

Range Selection:

The GPR-3500MO portable oxygen purity analyzer is equipped with a single 0-100% measuring range (see specification); accordingly,
there is no difference between auto and manual sampling.

Start-Up is complete . . .

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Zero Calibration

In theory, the oxygen sensor produces no signal output when exposed to an oxygen free sample gas. However, the portable oxygen
purity analyzer will generate an oxygen reading when sampling oxygen free sample gas due to:

¾ Contamination or quality of the zero gas
¾ Minor leakage in the sample line connections
¾ Residual oxygen dissolved in the sensor’s electrolyte
¾ Tolerances of the electronic components

As mandated by the FDA, calibration requires the use of certified zero (99.9% nitrogen minimum purity) and span (99.2% oxygen
minimum purity). For optimum accuracy and to take advantage of the portable oxygen purity analyzers’ inherent accuracy of 0.1%,
perform the zero and span calibration before each certification. Otherwise calibrate every eight (8) hours.

Medical grade oxygen:

The FDA requires the use of certified gases for zeroing and calibrating analyzers used in certifying medical grade oxygen. Advanced
Instruments Inc. recommends zeroing and calibrating the analyzer before each certification.

The analyzer zero gas must be a certified cylinder of nitrogen with a minimum purity of 99.9%. Once the analyzer has been zeroed
(described below), calibrate (described below) with a certified cylinder of oxygen with a minimum purity of 99.2%.

Non-medical grade oxygen applications:

In non-medical grade oxygen applications the analyzer does not require zeroing before every calibration. It is recommended the
analyzer be calibrated at least monthly. In most cases nitrogen zero gas of 99% minimum purity and a span gas of 95-100% oxygen
purity is sufficient.

For the reasons above, it is not practical to zero a percent portable oxygen purity analyzer. Finding the true zero offset is not always
necessary particularly in the case of applications requiring higher level oxygen measurements because of the low offset value, normally
< 0.1 ppm, is not material to the accuracy of higher level measurements.

Caution: Prematurely zeroing the analyzer can cause a negative reading in both the ZERO and SAMPLE modes.

Default Zero:

The software will eliminate any previous zero calibration adjustment and display the actual the signal output of the sensor at a
specified oxygen concentration. For example, assuming a zero gas is introduced, the display will reflect an oxygen reading representing
basically the zero calibration adjustment as described above. This feature allows the user to test the sensor’s signal output without
removing it from the sensor housing.

Recommendation: Initiate the DEFAULT ZERO procedure before performing either a ZERO or SPAN CALIBRATION.

Procedure – Zero Calibration:

Refer to Span Calibration below for the detailed procedure. Differences include the displays illustrated below, substituting a suitable
zero gas for the span gas.

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATE.

3. Press the ENTER key to select the highlighted menu option.

4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT ZERO, to remove all previous adjustments.

5. Press the ENTER key to select the highlighted menu option.

6. Repeat to select ZERO CALIBRATE.

7. The following displays appear:

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MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE
CALIBRATE

24.5 C 100 KPA

8. Press the ENTER key to calibrate or MENU key to abort and return to SAMPLING mode.

0.000 PPM

ZERO

CALIBRTION

ENTER TO CALIBRATE

MENU TO ABORT

9. Allow approximately 60 seconds for the calibration process while the processor determines whether the signal output or reading
has stabilized within 60% of the full scale low range.

10. Both the Zero Calibrate and Span Calibrate functions result in the following displays:

PASSED

CALIBRATION

For non-medical grade oxygen analysis, satisfying users that the zero offset is reasonably acceptable for their application can be

accomplished much quicker. Unless the zero gas is contaminated or there is a significant leak in the sample connections, the portable
oxygen purity analyzer should read less than 100 ppm oxygen within 10 minutes after being placed on zero gas.

The maximum zero calibration adjustment permitted is 60% of the lowest full scale range available, which normally is 1%. Thus the
maximum zero calibration adjustment or zero offset is 0.6% oxygen. Accordingly, the portable oxygen purity analyzers’ ZERO has not
been adjusted prior to shipment because the factory conditions are different from the application condition at the user’s installation.

MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE
CALIBRATE

24.5 C 100 KPA

>>>

OR

>>>

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN
OUTPUT ZERO

FAILED

CALIBRATION

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN
OUTPUT ZERO

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Advanced Instruments Inc.

Output Zero

Accuracy due to manufacturer tolerances may result in a slight difference between the LCD display and the 0-1V analog output.
However, the difference is less than 0.25% of range and falls well below the specified accuracy of the analyzer. In rare instances the 0­1V analog signal output may not agree to the reading displayed by the LCD. This feature enables the user to adjust the 0V analog
signal output when the LCD displays 00.00. Note: Adjust the 1V analog signal output with the OUTPUT SPAN option described below.

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.

3. Press the ENTER key to select the highlighted menu option and the following displays appear:

MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE

CALIBRATION

4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT ZERO.

5. Press the ENTER key to select the highlighted menu option.

6. The following display appears:

100.0

OUTPUT ZERO OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

7. Compute the adjustment value as described in Appendix B or consult the factory. The true adjustment value must be determined
empirically by trial and error. Adjust the initial adjustment value for additional percent errors.

090.0

OUTPUT ZERO OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

8. Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to
the desired digit of the OUTPUT ZERO OFFSET value.

9. Press the ARROW keys to enter the OUTPUT ZERO OFFSET value.

10. Repeat until the complete OUTPUT ZERO OFFSET value has been entered.

11. Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.

12. The system returns to the SAMPLING mode.

>>>

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN

OUTPUT ZERO

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Advanced Instruments Inc.

Span Calibration

Maximum drift from calibration temperature is approximately 0.11% of reading per °C. The analyzer has been calibrated at the factory.
However, in order to obtain reliable data, the analyzer must be calibrated at the initial start-up and periodically thereafter. The
maximum calibration interval recommended is approximately 3 months, or as determined by the user’s application.

Calibration involves adjusting the portable oxygen purity analyzer electronics to the sensor’s signal output at a given oxygen standard.
As mandated by the FDA, calibration requires the use of certified zero (99.9% nitrogen minimum purity) and span (99.2% oxygen
minimum purity). For optimum accuracy and to take advantage of the portable oxygen purity analyzers’ inherent accuracy of 0.1%,
perform the zero and span calibration before each certification. Otherwise calibrate every eight (8) hours.

Recommendation: Initiate the DEFAULT SPAN procedure before performing either a ZERO or SPAN CALIBRATION.
Caution: The user must ascertain that the oxygen reading (actually the sensor’s signal output) has reached a stable value within the

limits entered below before entering the span adjustment. Failure to do so will result in an error.
Caution: Do not attempt to span the portable oxygen purity analyzer with air or 21% oxygen and then operate it for either elevated

or high purity oxygen measurements.

Medical grade oxygen:

The FDA requires the use of certified gases for zeroing and calibrating analyzers used in certifying medical grade oxygen. Advanced
Instruments Inc. recommends zeroing and calibrating the analyzer before each certification.

The analyzer zero gas must be a certified cylinder of nitrogen with a minimum purity of 99.9%. Once the analyzer has been zeroed
(described below), calibrate (described below) with a certified cylinder of oxygen with a minimum purity of 99.2%.

Non-medical grade oxygen applications:

In non-medical grade oxygen applications the analyzer does not require zeroing before every calibration. It is recommended the
analyzer be calibrated at least monthly. In most cases nitrogen zero gas of 99% minimum purity and a span gas of 95-100% oxygen
purity is sufficient.

Default Span

The software will set the SPAN adjustment based on the average oxygen reading (actually the sensor’s signal output) at a specified
oxygen concentration. For example, when a span gas is introduced, the micro-processor will display an oxygen reading within +
the span gas value. This feature allows the user to test the sensor’s signal output without removing it from the sensor housing.

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATE.

3. Press the ENTER key to select the highlighted menu option.

4. The following displays appears:

MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE
CALIBRATE

24.5 C 100 KPA

Required components: Refer to Installing Span Gas section above.

Procedure – Span Calibration:

This procedure assumes a span gas under positive pressure and is recommended for a portable oxygen purity analyzer without an
optional sampling pump, which if installed downstream of the sensor should be placed in the OFF position and disconnected so the
vent is not restricted during calibration.

>>>

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN
OUTPUT ZERO

50% of

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Advanced Instruments Inc.

Caution: To assure an accurate calibration, the temperature and pressure of the span gas must closely approximate the sample
conditions. The GPR-3500MO has a single 0-100% range and should be calibrate as described above.

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATE.

3. Press the ENTER key to select the highlighted menu option.

4. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT SPAN, to remove all previous adjustments.

5. Press the ENTER key to select the highlighted menu option.

6. Repeat to select SPAN CALIBRATE.

7. The following displays appear:

MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE
CALIBRATE

24.5 C 100 KPA

8. Assure there are no restrictions in vent line.

9. Regulate the pressure and control the flow rate as described above at 5-30 psig and a 2 SCFH flow rate.

10. Allow the span gas to flow for 2-3 minutes to purge the air trapped in the span gas line.

11. Disconnect the sample gas line and install the purged span gas line.

12. Caution: Keep the span gas flowing and wait until the reading is stable before proceeding with calibration.

13. Press the ENTER key to select the SPAN CALIBRATE option.

14. Note: A span gas concentration above 1000 ppm dictates the selection of the PERCENT option.

15. Advance the reverse shade cursor using the ARROW keys to highlight the desired GAS CONCENTRATION.

16. Press the ENTER key to select the highlighted menu option.

GAS CONCENTRATION

PERCENT

PPM

17. The user must ascertain that the oxygen reading (actually the sensor’s signal output) has reached a stable value within the limits
entered below before entering the span adjustment. Failure to do so will result in an error.

18. The following display appears:

000.00 %

PRESS UP OR DOWN
TO CHANGE VALUE
SELECT TO SAVE
ESC TO RETURN

18. Press the UP/ DOWN ARROWS to enter the first digit of the span value.

19. Press the ENTER key to advance the underline cursor right to the second digit of the span value.

20. Press the MENU key to advance the underline cursor left to the previous digit.

21. Press the UP/ DOWN ARROWS to enter the second digit of the span value.

22. Repeat until the complete span value has been entered.

>>>

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN

OUTPUT ZERO

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Advanced Instruments Inc.

100.00 %

SPAN

CALIBRATION

ENTER TO CALIBRATE

MENU TO ABORT

23. Press ENTER to initiate the span calibration procedure

24. Allow approximately 60 seconds for the calibration process while the processor determines whether the signal output or reading
has stabilized within 60% of the full scale low range.

25. Both the ZERO CALIBRATE and SPAN CALIBRATE functions result in the following displays:

26. If the calibration is successful, the analyzer returns to the SAMPLING mode after 30 seconds.

PASSED

CALIBRATION

OR

FAILED

CALIBRATION

93.3 %

AUTO SAMPLING

100% RANGE

24.5 C 100 KPA

18. If the calibration is unsuccessful, return to the SAMPLING mode with span gas flowing through the portable oxygen purity
analyzer, make sure the reading stabilizes and repeat the SPAN CALIBRATE procedure before concluding the equipment is
defective.

19. Before disconnecting the span gas line and connecting the sample gas line, restart if necessary the flow of sample gas and allow it
to flow for 1-2 minutes to purge the air inside the line.

20. Disconnect the span gas line and replace it with the purged sample gas line.

21. Wait 10-15 minutes to ensure the reading is stable and proceed to sampling.

Output Span:

Accuracy due to manufacturer tolerances may result in a slight difference between the LCD display and the 0-1V analog output.
However, the difference is less than 0.25% of range and falls well below the specified accuracy of the analyzer. In rare instances the 0­1V signal output may not agree to the reading displayed by the LCD. This feature enables the user to adjust the 1V signal output
should the LCD display not agree. Note: Adjust the 0V signal output with the OUTPUT ZERO option described above.

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.

3. Press the ENTER key to select the highlighted menu option.

4. The following displays appear:

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MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE

CALIBRATION

CONFIG ALARMS
BYPASS ALARMS

5. Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT SPAN.

6. Press the ENTER key to select the highlighted menu option and the following display appears:

100.0

OUTPUT SPAN OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

7. Compute the adjustment value as described in Appendix B or consult the factory. The true adjustment value must be determined
empirically by trial and error. Adjust the initial adjustment value for additional percent errors.

099.0

OUTPUT SPAN OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

8. Press the ENTER key to advance the underline cursor right or press the MENU key to advance the underline cursor left to reach to
the desired digit of the OUTPUT SPAN OFFSET value.

9. Press the ARROW keys to enter the OUTPUT SPAN OFFSET value.

10. Repeat until the complete OUTPUT SPAN OFFSET value has been entered.

11. Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.

12. The system returns to the SAMPLING mode.

>>>

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO

OUTPUT SPAN

OUTPUT ZERO

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Advanced Instruments Inc.

Sampling

GPR-3500MO Oxygen Portable oxygen purity analyzer requires positive pressure to flow the sample gas by the sensor to measure the
oxygen concentration in a sample gas. If not available see Pressure & Flow section.

Note: Prematurely zeroing the portable oxygen purity analyzer can cause the portable oxygen purity analyzer to display a negative
reading in both the ZERO and SAMPLE modes.

Procedure:

1. Following calibration the portable oxygen purity analyzer returns to the SAMPLE mode after 30 seconds.

2. Selecting the desired sampling mode is not applicable with this single range analyzer - auto or manual are the same.

3. Use metal tubing to transport the sample gas to the portable oxygen purity analyzer.

4. The main consideration is to eliminate air leaks which can affect oxygen measurements above or below the 20.9% oxygen
concentration in ambient air - ensure the sample gas tubing connections fit tightly into the 1/8” male NPT to tube adapter, and,
the NPT end is taped and securely tightened into the mating male quick disconnect fittings which mate with the female fittings on
the portable oxygen purity analyzer

5. Assure there are no restrictions in the sample line.

6. For sample gases under positive pressure the user must provide a means of controlling the inlet pressure between 5-30 psig and
the flow of the sample gas between 1-5 SCFH, a flow rate of 2 SCHF is recommended

7. For sample gases under atmospheric or slightly negative pressure an optional sampling pump is recommended to draw the sample
into the portable oxygen purity analyzer. Generally, no pressure regulation or flow control device is involved.

8. Caution: If the analyzer is equipped with an optional sampling pump and is intended for use in both positive and
atmospheric/slightly negative pressure applications where a flow meter valve is involved – ensure the valve is completely open
when operating the sampling pump. Refer to the Pressure & Flow section above.

9. Assure the sample is adequately vented for optimum response and recovery – and safety.

10. Allow the oxygen reading to stabilize for approximately 10 minutes at each sample point.

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 (voiding the sensor
warranty).

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 particulates, liquids or condensation collect on the sensor that could block the diffusion of oxygen into the

sensor.
If the portable oxygen purity analyzer is equipped with an optional integral sampling pump (positioned downstream of the sensor)

¾

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.

Standby

¾ The portable oxygen purity analyzer has no special storage requirements.
¾ The sensor should remain connected during storage periods.
¾ Store the portable oxygen purity analyzer with the power OFF.
¾ If storing for an extended period of time, charge before operating.

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6 Maintenance

With exception of components related to optional equipment and charging the battery of portable analyzers, cleaning the electrical
contacts when replacing the sensor is the extent of the maintenance requirements of this analyzer as there are no serviceable parts in
the analyzer given the nature of the solid state electronics and sensor.

Serviceability: Except for replacing the oxygen sensor, there are no parts inside the portable oxygen purity analyzer for the operator
to service. Only trained personnel with the authorization of their supervisor should conduct maintenance.

Sensor Replacement

Periodically, the oxygen sensor will require replacement. The operating life is determined by a number of factors that are influenced by
the user and therefore difficult to predict. The Features & Specifications define the normal operating conditions and expected life of the
standard sensor utilized by the GPR-3500MO portable oxygen purity analyzer. Expected sensor life is inversely proportional to changes
in oxygen concentration, pressure and temperature.

Caution: DO NOT open the oxygen sensor. The sensor contains a corrosive liquid electrolyte that could be harmful if touched or
ingested, refer to the Material Safety Data Sheet contained in the Owner’s Manual. 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.

Procedure:

1. Remove the four (4) screws securing the hinged front panel of the portable oxygen purity
analyzer.

2. Caution: Do not remove or discard the gaskets from the enclosure. Failure to reinstall the
gasket will void the NEMA rating.

3. Unscrew the knurled lock nut connecting the cable to the sensor.

4. Disconnect and remove the female plug (including the knurled lock nut) molded to the
cable from the male receptacle attached to the sensor.

5. Unscrew the old sensor from the threaded hole in the sensor flow housing.

6. Open the barrier bag containing the new sensor.

7. If the sensor is equipped with a shorting loop, remove the shorting wire from the pins of
the female socket attached to the new sensor.

8. Screw the new sensor, finger tight plus 1/2 turn, into the threaded hole in the flow housing
and ensure the o-ring seal is engaged.

9. Assure the keyway registration of the female plug on the cable and male receptacle on the
sensor match up.

10. Push the female plug (including the knurled lock nut) molded to the cable into the male
receptacle attached to the new sensor.

11. Screw and tighten the knurled lock nut attached the cable onto to the male connector
attached to the sensor.

12. Replace the front cover of the portable oxygen purity analyzer, replace the gasket to
maintain CE approval and NEMA 4 rating and tighten the four (4) screws to secure the
front cover.

13. Calibrate the portable oxygen purity analyzer as described in section 5.

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Battery

Charging the battery requires a common 9VDC adapter (positive pole located inside the female connector) supplied with the analyzer
and a convenience outlet. The analyzer’s charging circuit accepts 9VDC from any standard AC 110V or 220V adapter. The electronic
design enables the analyzer to remain fully operable during the 8-10 hour charging cycle.

Procedure:

1. Unless the analyzer is to be operated while charging, turn the analyzer OFF when charging the battery for the shortest charging
cycle.

2. Connect the appropriate 9VDC adapter supplied with the analyzer to a 110V or 220V outlet.

3. Insert the male phone plug from the 9VDC adapter into the integral female CHARGE jack located on the bottom of the enclosure.

4. Caution: The analyzer is designed to operate in the charging mode, however, operating the analyzer in hazardous or explosive
atmospheres while charging the battery IS NOT recommended.

Service: A single charge is sufficient to operate the GPR-2000 Series analyzers continuously for a period of 60 days. Expect 8-10 hours
of service if the integral sampling pump of the GPR-2000P Series analyzer is operated continuously.

Warning indicators:

An LED indicator located on the front panel will light continuously during the CHARGE cycle.
A second LED indicator located on the front panel provides a blinking 72 hour warning LOW BATT of the need to recharge the battery.
Caution: Operating the analyzer beyond this 72 hour warning may permanently damage the battery.

7 Spare Parts

Recommended spare parts for the GPR-3500MO Oxygen Portable oxygen purity analyzer:

Item No. Description

GPR-11-120-OP Oxygen Sensor

Other spare parts:

Item No. Description

FITN-1018 Connector SS 1/8” MNPT to 1/8” Tube
FITN-1039 Elbow SS 1/8”
FMTR-1007-1 Flow Meter with Integral Metering Valve
A-3051 Housing Flow Adaptor
MTR-1011 Meter Digital Panel LCD Backlight
A-1151-B3 PCB Assembly Main / Display

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8 Troubleshooting

Symptom Possible Cause Recommended Action

Reading does not reflect
expected values

Oxygen reading drifts toward
zero

Slow response time
Erratic oxygen reading

No oxygen reading

High oxygen reading

Sensor was not calibrated at the pressure,
flow rate and temperature anticipated in the
sample gas stream

Indication sensor is nearing the end of its
useful life

Liquid covering sensing membrane
Presence of interference gases

Unauthorized maintenance
Defective electrical connection

Sensor failure

Inadequate control of flow rate
Abnormality in span gas

Recalibrate the analyzer

Replace sensor, see section 6 Maintenance

Gently remove with damp lint free towel.
Consult factory

Consult factory
Replace sensor and/or consult factory

See Pressure and Flow
Qualify source

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Advanced Instruments Inc.

9 Warranty

The design and manufacture of GPR Series oxygen analyzers, monitors and oxygen sensors are performed under a certified Quality
Assurance System that conforms to established standards and incorporates state of the art materials and components for superior
performance and minimal cost of ownership. Prior to shipment every analyzer is thoroughly tested by the manufacturer and
documented in the form of a Quality Control Certification that is included in the Owner’s Manual accompanying every analyzer. When
operated and maintained in accordance with the Owner’s Manual, the units will provide many years of reliable service.

Coverage

Under normal operating conditions, the monitor, analyzers and sensor are warranted to be free of defects in materials and
workmanship for the period specified in accordance with the most recent published specifications, said period begins with the date of
shipment by the manufacturer. The manufacturer information and serial number of this analyzer are located on the rear of the
analyzer. Advanced Instruments Inc. reserves the right in its sole discretion to invalidate this warranty if the serial number does not
appear on the analyzer.

If your Advanced Instruments Inc. monitor, analyzer and/or oxygen sensor is determined to be defective with respect to material
and/or workmanship, we will repair it or, at our option, replace it at no charge to you. If we choose to repair your purchase, we may
use new or reconditioned replacement parts. If we choose to replace your Advanced Instruments Inc. analyzer, we may replace it with
a new or reconditioned one of the same or upgraded design. This warranty applies to all monitors, analyzers and sensors purchased
worldwide. It is the only one we will give and it sets forth all our responsibilities. There are no other express warranties. This warranty
is limited to the first customer who submits a claim for a given serial number and/or the above warranty period. Under no
circumstances will the warranty extend to more than one customer or beyond the warranty period.

Limitations

Advanced Instruments Inc. will not pay for: loss of time; inconvenience; loss of use of your Advanced Instruments Inc. analyzer or
property damage caused by your Advanced Instruments Inc. analyzer or its failure to work; any special, incidental or consequential
damages; or any 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 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 other failure to follow the Owner’s Manual.

Service

Call Advanced Instruments Inc. at 909-392-6900 (or e-mail [e-mail]) between 7:30 AM and 5:00 PM Pacific Time Monday thru
Thursday or 8:00 AM to 12:00 pm on Friday. Trained technicians will assist you in diagnosing the problem and arrange to supply you
with the required parts. You may obtain warranty service by returning you analyzer, postage prepaid to:

Advanced Instruments Inc.

2855 Metropolitan Place

Pomona, Ca 91767 USA

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

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Advanced Instruments Inc.

10 MSDS – Material Safety Data Sheet

Product Identification

Product Name Oxygen Sensor Series - PSR, GPR, AII, XLT
Synonyms Electrochemical Sensor, Galvanic Fuel Cell
Manufacturer Advanced Instruments Inc., 2855 Metropolitan Place, Pomona, CA 91767 USA
Emergency Phone Number 909-392-6900
Preparation / Revision Date January 1, 1995
Notes Oxygen sensors are sealed, contain protective coverings and in normal conditions do not present a health

Specific Generic Ingredients

Carcinogens at levels > 0.1% None
Others at levels > 1.0% Potassium Hydroxide or Acetic Acid, Lead
CAS Number Potassium Hydroxide = KOH 1310-58-3 or Acetic Acid = 64-19-7, Lead = Pb 7439-92-1
Chemical (Synonym) and Family Potassium Hydroxide (KOH) – Base or Acetic Acid (CH

General Requirements

Use Potassium Hydroxide or Acetic Acid - electrolyte, Lead - anode
Handling Rubber or latex gloves, safety glasses
Storage Indefinitely

Physical Properties

Boiling Point Range
Melting Point Range
Freezing Point
Molecular Weight KOH = 56 or Acetic Acid – NA, Lead = 207
Specific Gravity
Vapor Pressure
Vapor Density KOH – NA or Acetic Acid = 2.07
pH KOH > 14 or Acetic Acid = 2-3
Solubility in H
% Volatiles by Volume None
Evaporation Rate Similar to water

Appearance and Odor Aqueous solutions: KOH = Colorless, odorless or Acetic Acid = Colorless, vinegar-like odor

O Complete

2

Fire and Explosion Data

Flash and Fire Points Not applicable
Flammable Limits Not flammable
Extinguishing Method Not applicable
Special Fire Fighting Procedures Not applicable
Unusual Fire and Explosion Hazards Not applicable

hazard. Information applies to electrolyte unless otherwise noted.

H) – Acid, Lead (Pb) – Metal

3CO2

KOH = 100 to 115° C or Acetic Acid = 100 to 117° C
KOH -10 to 0° C or Acetic Acid – NA, Lead 327° C
KOH = -40 to -10° C or Acetic Acid = -40 to -10° C

KOH = 1.09 @ 20° C, Acetic Acid = 1.05 @ 20° C
KOH = NA or Acetic Acid = 11.4 @ 20° C

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Advanced Instruments Inc.

Reactivity Data

Stability Stable
Conditions Contributing to Instability None
Incompatibility KOH = Avoid contact with strong acids or Acetic Acid = Avoid contact with strong bases
Hazardous Decomposition Products KOH = None or Acetic Acid = Emits toxic fumes when heated
Conditions to Avoid KOH = None or Acetic Acid = Heat

Spill or Leak

Steps if material is released Sensor is packaged in a sealed plastic bag, check the sensor inside for electrolyte leakage. If the sensor

Disposal

Health Hazard Information

Primary Route(s) of Entry Ingestion, eye and skin contact
Exposure Limits Potassium Hydroxide - ACGIH TLV 2 mg/cubic meter or Acetic Acid - ACGIH TLV / OSHA PEL 10 ppm

Ingestion Electrolyte could be harmful or fatal if swallowed. KOH = Oral LD50 (RAT) = 2433 mg/kg or Acetic Acid =

Eye Electrolyte is corrosive and eye contact could result in permanent loss of vision.
Skin Electrolyte is corrosive and skin contact could result in a chemical burn.
Inhalation Liquid inhalation is unlikely.
Symptoms Eye contact - burning sensation. Skin contact - soapy slick feeling.
Medical Conditions Aggravated None
Carcinogenic Reference Data KOH and Acetic Acid = NTP Annual Report on Carcinogens - not listed; LARC Monographs - not listed;

Other Lead is listed as a chemical known to the State of California to cause birth defects or other reproductive

Special Protection

Ventilation Requirements None
Eye Safety glasses
Hand Rubber or latex gloves
Respirator Type Not applicable
Other Special Protection None

Special Precautions

Precautions Do not remove the sensor’s protective Teflon and PCB coverings. Do not probe the sensor with sharp

Transportation Not applicable

leaks inside the plastic bag or inside an analyzer sensor housing do not remove it without rubber or latex
gloves and safety glasses and a source of water. Flush or wipe all surfaces repeatedly with water or wet
paper towel (fresh each time).

In accordance with federal, state and local regulations.

(TWA), Lead - OSHA PEL .05 mg/cubic meter

Oral LD50 (RAT) = 6620 mg/kg

OSHA - not listed

harm.

objects. Wash hands thoroughly after handling. Avoid contact with eyes, skin and clothing.
Empty sensor body may contain hazardous residue.

29

Advanced Instruments Inc.

30

Advanced Instruments Inc.

Output Zero Procedure:

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.

3. Press the ENTER key to select the highlighted menu option.

4. The following displays appear:

MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE

CALIBRATION

CONFIG ALARMS
BYPASS ALARMS

>>>

5. Advance the reverse shade cursor using the ARROW keys to highlight OUTPUT ZERO.

6. Press the ENTER key to select the highlighted menu option.

7. The following display appears:

100.0

OUTPUT ZERO OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

8. Enter the OUTPUT ZERO adjustment value as follows . . .

9. Selecting digits of the adjustment value to change - Press the ENTER key to advance the underline cursor right or press the MENU
key to advance the underline cursor left to reach to the desired digit.

10. Changing the digits of the adjustment value . . . Press the UP/DOWN ARROW keys to change a digit of the adjustment value.

11. Repeat steps 9 and 10 until the complete zero value has been entered and the following display appears.

099.0

OUTPUT ZERO OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

12. Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.

13. The system returns to the SAMPLING mode.

14. Note: After the initial adjustment is made, check the actual signal output at the PLC and if necessary calculate a further fine
tuning adjustment value as illustrated above.

15. Enter subsequent fine tuning adjustments as described above.

Output Span Procedure:

1. Access the MAIN MENU by pressing the MENU key.

2. Advance the reverse shade cursor using the ARROW keys to highlight CALIBRATION.

3. Press the ENTER key to select the highlighted menu option.

4. The following displays appear:

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN

OUTPUT ZERO

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Advanced Instruments Inc.

MAIN MENU

AUTO SAMPLE
MANUAL SAMPLE

CALIBRATION

CONFIG ALARMS
BYPASS ALARMS

>>>

5. Advance the reverse shade cursor using the ARROW keys to highlight OUTPUT SPAN.

6. Press the ENTER key to select the highlighted menu option.

7. The following display appears:

100.0

OUTPUT SPAN OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

8. Enter the adjustment value as follows . . .

9. Selecting digits of the adjustment value to change - Press the ENTER key to advance the underline cursor right or press the MENU
key to advance the underline cursor left to reach to the desired digit.

10. Changing the digits of the adjustment value . . . Press the UP/DOWN ARROW keys to change a digit of the adjustment value.

11. Repeat steps 9 and 10 until the complete span value has been entered and the following display appears.

064.0

OUTPUT SPAN OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

12. Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.

13. The system returns to the SAMPLING mode.

14. Note: After the initial adjustment is made, check the actual signal output at the PLC and if necessary calculate a further fine
tuning adjustment value as illustrated above.

15. Enter subsequent fine tuning adjustments as described above.

075.0

OUTPUT SPAN OFFSET

PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN

16. Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.

17. The system returns to the SAMPLING mode.

CALIBRATION

SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO

OUTPUT SPAN

OUTPUT ZERO

32