Analytical Industries GPR-3100 User Manual

Advanced Instruments Inc.

Owner’s Manual

GPR-3100
Oxygen Purity Analyzer

Advanced Sensor Technology
24 Month Operating Life in 100% Oxygen
Inherent Accuracy 0.1%, Resolution 00.01%
Auto Ranging & Suppressed Range Capability
Temperature Controlled & Barometric Compensationsy

2855 Metropolitan Place, Pomona, CA 91767 USA ♦ Tel: [phone], Fax: [phone], e-mail: [e-mail], www.aii2.com

Table of Contents

Advanced Instruments Inc.

Introduction

Quality Control Certification

Safety

Features & Specifications

Operation

Maintenance

Spare Parts

Troubleshooting

Warranty

1
2
3
4
5
6

7
8
9

(MSDS) Material Safety Data Sheet

Reference Drawings

Rev 3/2004 i

10

As Required

T

1 Introduction

Advanced Instruments Inc.

Thank You For Your Business

Your new oxygen analyzer is a precision piece of equipment

designed to give you years of use in variety of industrial
oxygen applications.

his analyzer is designed to measure the purity of oxygen gas
containing innert gases such as nitrogen, helium or argon
and/or other reactive gases such as hydrogen and gaseous
hydrocarbon gases as minor contaminants.

In order to derive maximum performance from your new
oxygen analyzer, please read and follow the guidelines
provided in this Owner’s Manual.

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: _______________________
Every effort has been made to select the most reliable state of

the art materials and components designed for superior
performance and minimal cost of ownership. This analyzer was
tested thoroughly by the manufacturer 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.

Advanced Instruments Inc. appreciates your business and
pledge to make effort to maintain the highest possible quality
standards with respect to product design, manufacturing and
service.

1

Advanced Instruments Inc.

2 Quality Control Certification

Date: Customer: Order No.: Pass
Model

Sensor
Accessories

Configuration

Test - Electronics

Test - Gas Phase

Final

Notes

GPR-3100 High Purity % O2 Analyzer
GPR-11-120-OP
Owner’s Manual
CABL-1008 Power Cord Black 3 Conductor UL/CSA
HRWR-1021 Wrench 5/16 Combination
Ranges: 0-100%; suppressed 50-100%, 80-100%, 90-100%
A-1146-E-50 PCB Assembly Micro-processor / Display
A-1147-E-50 PCB Assembly Power Supply / Interconnection
Software Rev: _______
Wetted parts: Stainless steel
Power: Specify: ( x ) 100/120 VAC, ( ) 220/240 VAC
Enclosure: ( ) Panel mount 10.8”W x 7.5”H

( ) Rack mount panel 19”W x 12”H
( x ) Wall mount 12”W x 12”H x 8”D

Factory default zero (without sensor)
Factory default span @ 20 uA
Alarm relays activate/deactivate to changes in O

concentration

2

Sensor failure alarm
Power failure alarm
Analog signal output 0-1V and 4-20mA
Range ID voltage output
Baseline drift < ± 1% FS 90-100% range over 24 hour period
Noise level < ± 1.0% FS
Span adjustment within 10-50% FS
Temperature controller (CNTL-_______) set at 85°F
Overall inspection for physical defects

1 of 1 analyzer due ASAP

GPR-3100 Rev 7/2004 2 1 of 1

Advanced Instruments Inc.

3 Safety

This section summarizes the essential generic precautions applicable to all analyzers. Additional
precautions specific to individual analyzers 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 all warnings on the analyzer, accessories (if any) and in this Owner’s Manual.
Follow Instructions: Observe all precautions and operating instructions. Failure to do so may result in

personal injury or damage to the analyzer.

Inlet Pressure: Recommended 5-30 psi, 100 psi maximum.
Outlet Pressure: The sample gas vent pressure should be atmospheric.
Oxygen Sensor: DO NOT open the sensor. The sensor contains a corrosive liquid electrolyte that could

be harmful if touched or ingested, refer to the Material Safety Data Sheet contained in the Owner’s
Manual appendix. Avoid contact with any liquid or crystal type powder in or around the sensor or sensor
housing, as either could be a form of electrolyte. Leaking sensors should be disposed of in accordance
with local regulations.

Mounting: The analyzer is approved for indoor use only. It may be used outdoors with optional
enclosures. Mount as recommended by the manufacturer.

Power: Supply power to the analyzer only as rated by the specification in Section 4 nd/or markings on
the analyzer enclosure. The wiring/cords that connect the analyzer to the power source should be
installed in accordance with recognized electrical standards and so they are not pinched particularly near
the power source and the point where they attach to the analyzer. Never yank a power cord to remove it
from an outlet or from the analyzer.

Operating Temperature: The maximum operating temperature is 45º C.
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.

Rev 10/2002 3

1

Advanced Instruments Inc.

3 Safety

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 the Owner’s
Manual appendix. Avoid contact with any liquid or crystal type powder in or around the sensor or sensor
housing, as either could be a form of electrolyte. Leaking sensors should be disposed of in accordance
with local regulations.

Troubleshooting: Consult the guidelines in Section 8 for advice on the common operating errors before
concluding that your 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 per 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: Isolate ppb and ppm oxygen sensors as described in this manual and disconnect the
power when the analyzer is left unused for a long period of time.

Rev 10/2002 3

2

Advanced Instruments Inc.

Gas analysis solutions through advanced analyzer and sensor technology

Technical Specifications

Accuracy: < 1% of FS range at constant conditions; inherent accu-

racy of 0.1% following calibration with 95-100% oxygen

Analysis: 0-100% full scale range; 50-100%, 80-100%, 90-100 sup-

Application: Continuous monitoring of high purity oxygen levels up to

Approvals: CE
Area Classification: General purpose
Alarms: 2 adjustable form C relay contacts non-latching; “weak

Calibration:

Compensation: Barometric pressure and temperature; temperature con-

Connections: Compression tube fittings 1/8” inlet; 1/4” vent
Controls: Water resistant keypad; menu driven range selection,

Data Acquisition: Selectable data point intervals
Display:

Enclosure: Painted aluminum 7.5” x 10.8” x 12.25” panel mount
Flow Sensitivity: None between 1-3 SCFH, 2 SCFH recommended

Linearity: > .995 over all ranges
Pressure: Inlet - regulate to 5-30 psig; vent - atmospheric

Power: Specify 100/120 or 220/240 VAC
Response Time: 90% of final FS reading < 13 seconds
Sample System: Flow control, flow indicator, special integral sample

Sensitivity: 0.1% oxygen
Sensor Model: GPR-11-120-OP - requires no maintenance

Sensor Life: 24 months in 100% oxygen at 25ºC and 1 atm
Signal Output: 4-20mA isolated and 0-1V
Temp. Range: 5º to 45ºC
Warranty: 12 months analyzer; 12 months sensor
Wetted Parts: 316 stainless steel

Optional Equipment

Bezel for 19” rack mounting, wall mount NEMA4 and 4X enclosure
Sample conditioning accessories - contac t factory

pressed ranges

100% oxygen in inert, helium, hydrogen and mixed gases

sensor” indicator; power failure; system failure
Certified gas of O

oxygen for optimum accuracy; otherwise, O
approximate 80% of full scale range

trolled heated sample system and sensor housing

calibration, alarm and system functions

Graphical LCD 5 x 2.75; resolution .01%; displays real time
ambient temperature and pressure

temperature equalization system

balance N2 approximating 95-100%

2

content should

2

GPR-3100
Oxygen Purity Analyzer

Breakthrough Sensor Technology
24 month life at 100% Oxygen Levels
Accuracy < 1% FS Range
Sensitivity < 0.1% Oxygen
No maintenance
Inherent Accuracy 0.1% Following
Calibration With 100% Oxygen
4 Standard Analysis Ranges including
3 Suppressed Ranges 50/80/90-100%
Auto Zero, Span Calibration
Temperature Controlled Sample System
Pressure Compensated
Remote Communication Link
Certified ISO 9001 QA System

‘the only electrochemical

sensor based analyzer

capable of analyzing

> 99.5% pure oxygen

continuously 24/7

for 24 months‘

2855 Metropolitan Place, Pomona, CA 91767 USA ♦ Tel: [phone], Fax: [phone], www.aii1.com, e-mail: [e-mail] Rev 5/05

Advanced Instruments Inc.

5 Operation

Principle of Operation

The GPR-3100 oxygen analyzer incorporates an advanced galvanic fuel cell type sensor capable of
measuring 100% oxygen on a suppressed range of 90-100% on a continuous basis It is the only
electrochemical sensor based analyzer capable of this measurement.

Background

The production of pure oxygen has been confined to the production of medical grade oxygen (99.0%,
typically specified at 99.5% or greater purity). However, the demand for oxygen is expanding rapidly due
largely to recent developments in chemical processes requiring elevated concentrations of oxygen (85­95%) that boost yields and reduce emissions without significant cost increases and to a lesser extent the
growth of transfilling oxygen (92%) cylinders for home care use. The oxygen supplied can be be
generated cryogenically or by pressure (PSA) or vacuum (VSA) swing adsorption methods.

Historically producers and users have relied on analyzers based on paramagnetic method for measuring
oxygen purity. These sensor offer highly accurate results especially at the suppressed ranges of 90-100%
oxygen. However, they are very sensitive to changes in the flow rate of sample gas, the presence of
minute particulates and moisture, temperature variations and vibration. Consequently, paramagnetic
analyzers are expensive and require frequent almost daily calibration.

Analyzers based on galvanic sensor concept have always generated an interest for oxygen purity
measurements because they are specific to oxygen, versatile, low maintenance and inexpensive.
However, short sensor life (3-4 months at best) and the gradual drop (drift) in the signal output of the
micro-fuel cell with time has precluded their use.

Major Advancement in Galvanic Fuel Cell Sensor Technology

In competing with paramagnetic devices the focus was primarily on advancing the galvanic sensor
technology but also included temperature controlling the sample gas and automatically compensating the
signal output of the sensor for barometric pressure variations to assure a stable ‘drift free’ oxygen
measurement.

An advanced galvanic sensor has been developed that provides two years of sensor life and is capable of
operating properly on a continuous basis in 100% oxygen concentrations. This proprietary design
addresses the challenges of:

Providing a sufficient amount of anode material to support the reduction of oxygen over several years.
Maintaining at all times a sufficient concentration of hydroxyl ions to support the reduction of oxygen at

and near the sensing cathode.
Preventing the build-up of PbO at and near the sensing cathode (that eventually starts precipitating and

covers the sensing cathode) that can cause the signal output of the sensor to drop (drift) with time.
Through proprietary means the production rate of the reaction product is controlled without sacrificing

either the fast less than 13 second response time or any of the features (described above) of the micro­fuel cell analyzer. The resulting on-line and portable analyzers are approximately half the cost of their
paramagnetic counterparts.

The performance of the sensor was validated over 14 months of testing and exhibited excellent stability
in 100% oxygen. The sample flow rate was set at 0.1 lpm (and insensitive to changes of up to 1.0 lpm)
with the sample vented to the atmosphere via ¼” diameter tube to minimize the backpressure.

GPR-3100 Rev 2/05 1

Advanced Instruments Inc.

5 Operation

With the sensor and sample gas lines temperature controlled and the signal output of the sensor
compensated for ambient pressure variations it was possible to measure oxygen in the suppressed range
of 90-100% with less than +
periodically and found to be within +
scale over the fourteen month test period
suggesting the interval between calibrations
could be extended to several months.

To demonstrate the stability of the new
analyzer, 99.5% oxygen was introduced
(typically the threshhold for gas manufacturers)
for 30 days and the output plotted as shown at
the right. The resolution of the analyzer’s 4-1/2
digit display is 0.01%.

The maximum variation in the signal output is

0.1% oxygen over a 24 hour period and is

+
primarily to the variation in ambient
temperature.

1% of full scale (+0.1% oxygen) accuracy. The calibration was checked

1% of full

100.00

99.00

98.00

97.00

% Oxy gen

96.00

95.00

94.00

93.00

92.00

91.00

90.00
2 5 8 11141720232629

30 Day Stability in

99.5% Oxyg en

90-100% Suppressed Range

Day s

Advanced Sensor Technology Overview:

The sensor 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 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.

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.

Additional features of the micro-processor based electronics include manual or auto ranging, optional
integral sample, span and zero inlet valves for auto-zero and auto-calibration at user specified intervals,
data acquisition and temperature tracking all which can be controlled remotely. Analog outputs, 0-1V and
an isolated 4-20mA, and an USB communication link are provided along with field selectable alarms with
dry relay contacts, power and range identification. An unique algorithm predicts and display a message
indicating a ‘weak sensor’ suggesting the sensor be replaced in the near future.

GPR-3100 Rev 2/05 2

Advanced Instruments Inc.

5 Operation

Sample System:

The GPR-3100 is supplied with stainless steel flow housing, fittings and tubing along with an integral flow
meter to provide optimum percentage range oxygen measurements. As a rule of thumb, the sample must
be properly presented to the sensor to ensure an accurate measurement. For optimum accuracy the
overall performance is enhanced by an temperature controlled heater system that controls the
temperature around the sensor to eliminate drift and daily calibration requirements associated with
competitive analyzers.

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]

Controlling Pressure & Flow

All electrochemical oxygen sensors respond to partial pressure changes in oxygen. The inlet pressure
must always be higher than the pressure at the outlet vent which is normally at atmospheric pressure.
Despite the fact the oxygen reading is compensated for variations in barometric pressure (at the vent), it
is extremely critical for suppressed range measurements of 90-100% that backpressure be kept to an
absolute minimum. For this reason the analyzer is equipped with 1/8” inlet connections and ¼” vent
connections.

Flow Through Configuration:

The sensor is exposed to sample gas that must flow or be drawn through metal or plastic tubing, see
Application Pressure below, to the analyzer, through the analyzer’s internal sample system that includes
an o-ring sealed stainless steel sensor housing and finally is normally vented to atmosphere.

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 1liter per minute is recommended for optimum performance.

Assure that the vent line is connected to a ¼” or larger tube and is vented to atmosphere, with the
magnification associated with the use of suppressed ranges even the slightest amount of backpressure
will adversely affect the oxygen reading.

Caution: Do not place your finger over the vent (it pressurizes the sensor) to test the flow indicator
when gas is flowing to the sensor. Removing your finger (the restriction) generates a vacuum on the
sensor and may damage the sensor (voiding the sensor warranty).

Application Pressure - Positive:

A flow indicator with an integral metering valve positioned upstream of the sensor is provided for
controlling the sample flow rate between 1-5 SCFH. If necessary, a pressure regulator (with a metallic
diaphragm is recommended to prevent high oxygen readings resulting from the use of diaphragms of
more permeable materials) upstream of the flow control valve should be used to regulate the pressure.

Application Pressure - Atmospheric or Slightly Negative:

For accurate percentage range measurements, a sample pump is should be positioned downstream of
the sample inlet to draw the sample from the process through the analyzer’s sample system and by the
sensor. A flow indicator with an integral metering valve positioned downstream of the sensor is necessary
to obtain the recommended flow rate between 1-5 SCFH. If pump loading is a consideration, a second

GPR-3100 Rev 2/05 3

Advanced Instruments Inc.

5 Operation

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.

An eductor jet pump is an alternative to a pump that is used in classified areas since it has no moving
parts or to eliminate the maintenance associated with mechanical pumps. The eductor must be
positioned downstream of the sample outlet. The eductor has three (3) orifices and requires a source of
compressed gas which enters through the top and exits at the bottom while drawing a mild vacuum (and
sample gas) through the side orifice. A flow indicator with an integral metering valve positioned
downstream of the sensor is recommended for controlling the sample flow rate between 1-5 SCFH.

To avoid erroneous oxygen readings and damaging the sensor:

¾ Assure there are no restrictions in the sample line that could create and draw a vacuum exceeding

14” of water column on the sensor.

¾ Avoid excessive flow rates above 5 SCFH which generate backpressure on the sensor.
¾ Avoid sudden changes in pressure that can severely damage the sensor – assure a flow control valve

is positioned upstream of the analyzer’s inlet.

¾ Assure no particulates, liquids or condensation collect on the sensor that could block the diffusion of

oxygen into 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).

GPR-3100 Rev 2/05 4

Advanced Instruments Inc.

5 Operation

Calibration and Accuracy

Single Point Calibration: As previously described the galvanic oxygen sensor generates an electrical
current sensor exhibiting 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 +5% or better 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:

of errors: 1) those producing 'percent of reading errors', illustrated by Graph A below, such as +
temperature compensation
to make span adjustments and 2) those producing 'percent of full scale errors', illustrated by Graph B,
such as +1-2% linearity errors in readout devices, which are really minimal due to today's technology
and the fact that other errors are 'spanned out' during calibration.

GPR-3100 Rev 2/05 5

In light of the above parameters, the overall accuracy of an analyzer is affected by two types

5%

circuit, tolerances of range resistors and the 'play' in the potentiometer used

Advanced Instruments Inc.

5 Operation

Graph C illustrates these 'worse case' specifications that are typically used to develop an analyzer's
overall accuracy statement of +2% 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.

Recommendation: The analyzer may be calibrated by using a certified span gas of 80-90% value of
the range of analysis. For example, for analysis on 90-100% range, use 98-99% oxygen as the span gas
and for analysis on 80-90% oxygen, use 96-98% oxygen as the span gas.

Note: The accuracy of the analyzer is given as the % of full-scale. Therefore, the calibration of the
analyzer must be done on the range of analysis or one range above the range of analysis. The analysis of
the sample gas must be carried out on the range that provides the required accuracy.

GPR-3100 Rev 2/05 6

Advanced Instruments Inc.

5 Operation

Installation

The GPR-3100 Oxygen Analyzer consists of an electronic module, sensor housing and sample system
housed in a 10.8”W x 7.5”H x 12.25”D enclosure suitable for panel mounting or 19” rack mounting with
the optional panel. A 12”W x 12”H x 8”D wall mount configuration is also available.

An integral temperature controlled heating system maintains the temperature of the sensor at a pre-set
temperature and assures the stability not found in competitive analyzers. The analyzer has been tested
and calibrated by the manufacturer prior to shipment.

Installation Considerations:
The GPR-3100 is fully operational from the shipping container with the oxygen sensor installed and

calibrated at the factory prior to shipment. Once installed, we recommend the user allow the analyzer to
stabilize for 30 minutes and then recalibrate the device as instructed below.

¾ Mounting the analyzer and optional components such as coalescing or particulate filters and pumps.
¾ Assemble the necessary hardware for mounting the analyzer and optional components, 1/8” stainless

steel tubing for interconnecting the analyzer and optional components.

¾ Review the application conditions to ensure the sample is suitable for analysis.
¾ 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.

¾ Pressure & Flow: As described above.
¾ Moisture & Particulates: Prevent water and/or particulates from entering the sample system. They

can clog the tubing and damage the optional components such as pumps, scrubbers or sensors.
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. Consult the factory for recommendations concerning the proper
selection and installation of components.

¾ Contaminants: A gas scrubber and flow indicator with integral metering valve are required upstream

of the analyzer to remove interfering gases such as oxides of sulfur and nitrogen or hydrogen sulfide
that can produce false readings and reduce the expected life of the sensor. 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.

¾ Gas connections: Inlet gas lines require 1/8” diameter metal tubing whereas ¼” diameter tubing is

required for the vent. Span gas and required accessories are the responsibility of the user.

¾ Power connection: To meet hazardous area classification and weatherproofing requirements install

the interconnection wiring in rigid conduit.

¾ Output connections. To assure proper grounding, connect the 4-20mA signal output to the external

power source before attempting calibration adjustments.

¾ Establishing power to the electronics.
¾ Setting the alarm values (if applicable).
¾ Zeroing the analyzer (required only for very low percentage range measurements).
¾ Calibrating the analyzer.

GPR-3100 Rev 2/05 7