Analytical Industries Inc (AII) GPR-1600 Operating Manual

Technical Specifications *

Accuracy: < 2% of FS range under constant conditions
Analysis:

Application:

Approvals: CE
Area Classification: General purpose
Alarms:

Calibration:

Compensation: Barometric pressure and temperature
Connections: 1/4" compression tube fittings
Controls:

Data Acquisition:

Display:

Enclosure: Painted aluminum 7.5” x 10.8” x 12.25” panel mount
Flow: Not flow sensitive; recommended flow rate 2 SCFH

Linearity: > .995 over all ranges
Pressure:

Power:

Range ID:

Recovery Time: 60 sec in air to < 10 PPM in < 1 hour on N2 purge
Response Time: 90% of final FS reading < 10 seconds

Sample System:

Sensitivity: < 0.5% of FS range
Sensor Model:

Sensor Life: 24 months in < 1000 PPM O2 at 25ºC and 1 atm
Signal Output: 4-20mA isolated, 0-1V, and 0-5V
Temp. Range:

0-10, 0-100, 0-1000 PPM, 0-1%, 0-25% (CAL) FS
Auto-ranging or manual lock on a single range

Oxygen analysis in inert, helium, hydrogen, mixed and
acid (CO2) gas streams

Two adjustable form C relay contacts non-latching;
“weak sensor” indicator; power failure; system failure

Max interval—3 months. Use certified span gas with O2
content (balance N2) approximating 80% of full scale for
fast 20-30 minute recovery to online use. Alternatively,
air calibrate with clean source of compressed or ambient
(20.9% O2) air on 0-25% range and allow 60 minutes on
zero gas to recover to 10 ppm. For optimum accuracy,
calibrate one range higher than the range of interest.

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

Selectable data point intervals

Graphical LCD 5” x 2.75”; resolution .01 PPM; displays

real time ambient temperature and pressure

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

Universal 100-240 VAC; option heater system (specify
110 or 220 VAC)

1-5V; Optional (1) 4-20mA non-isolated OR (2) relay
contacts w/ 4-20mA or 1-5V

Stainless steel wetted parts consisting of flow control and
sample/bypass valves, flow indicator

GPR-12-333 for non-acid (CO2) gas streams
XLT-12-333 for gas mixture with > 0.5% CO2

5ºC to 45ºC (GPR sensor), -10°C to 45°C (XLT)

GPR-1600

PPM Oxygen Analyzer

Advanced Full Featured Process PPM O2 Analyzer

Advanced Sensor Technology

 Unmatched Performance in PPM O2 Analysis
 Unmatched Expected Life & Warranty
 Unmatched Recovery to 10 PPM
 Sensitivity < 0.5% FS Range
 Excellent Compatibility with 0-100% CO2

Bypass Sample System
2 Field Selectable Alarm Setpoints
Auto Ranging or Single Fixed
Options: Temperature Control
Auto-Zero and Auto-Cal

Remote Communication via USB,
RS232, RS485

Integral stainless steel bypass sample system
significantly increases user productivity. The
bypass valve isolates the sensor from high
oxygen levels when changing sample lines.

Warranty: 12 months analyzer; 12 months sensor

Optional Equipment

ISO 9001:2008 Certified

19” rack, wall mounting, auto zero/cal, remote communication-contact factory

* Specification 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

INTERTEK Certificate No. 485

GPR-1600 W

GPR-1600 W306

The sensor is the heart of any analyzer . . . which means sensor technology is the

critical factor in analyzer performance . . . don’t settle, get the best !

Sensor Housing

Constructed from stainless steel as are
all wetted parts, this unique design
features a compression type o-ring
seal that virtually eliminate air leaks.

An APIMS mass spectrometer verified
that the Bypass Sample System in­cluding this housing is capable of
accurately and repeatedly distinguish­ing hourly changes of 1 ppb oxygen
concentration.

Advancements:

Signal output 2x higher
Innovative design, materials

Bypass Sample System

Integral stainless steel bypass sample
system significantly increases user
productivity. The bypass isolates the
sensor from high oxygen levels when

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

changing sample lines.

Proprietary mfg process
Insensitive to vibration
Retain compact design
Low cost of ownership

Performance:

Accuracy < + 1% FS
Sensitivity 0.5% FS (50 ppb)
Service life 24 mos < 100 ppm
Recovery air to 10 ppm < 1 hr.
Op temp -20⁰C in 0-100% CO2
No sensor maintenance

Galvanic PPM

Oxygen Sensor

Advanced Instruments Inc.

GPR-1600

PPM Oxygen Analyzer

Owner’s Manual

Revised October 2013

2855 Metropolitan Place, Pomona, California 91767 USA ♦ Tel: [phone], Fax: [phone], e-mail:

[e-mail]

Table of Contents

Introduction 1

Quality Control Certification 2

Safety & Installation 3

Features & Specificat io n s 4

Operation 5

Maintenance 6

Spare Parts 7

Troubleshooting 8

Warranty 9

Advanced Instruments Inc.

Material Safety Data Sheets 10

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1. Introduction

Your new oxygen analyzer is a precision piece of equipment designed to give you years of use in a variety of
industrial oxygen applications.

This analyzer is d esigned to measur e oxygen concentrati on in inert gases, gaseous hydroc arbons, hydrogen, an d a
variety of gas mixt ures. In order t o derive maximum perf ormance f rom your new oxygen an alyzer, ple ase read an d
follow the guidelines provided in this Owner’s Manual.

The serial number o f th i s an alyzer may be fou n d o n t h e inside the analyzer. You sho u l d note the serial n u m ber in the
space provided and r etain 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 perfor mance and minim al cost of ownersh ip. This analyz er was tested tho roughly by the manufacturer for
best performan ce. However, modern el ectronic devices do require ser vice from time to ti me. The warran ty include d
herein plus a s taf f o f t r a i n ed professional technicians to quickly ser vi c e your analyzer is your assurance that w e 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.

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Customer: Order No.:
Model:

GPR-1600 PPM Oxygen Analyzer S/N _____________________

( ) XLT-12-333 PPM Oxygen Sen so r S/N _____________________

TOOL-1001 5/16” Combination Wrench

Configuration:

Ranges: 0-10 PPM, 0-100 PPM, 0-1000 PPM, 0-1%, 0-25%

( ) A-1174-10 PCB Power Supply / Interconnect, 5x Relay Contacts Range ID

( ) Sample, span, zero inlet solenoid valves

( X ) Temperature controlled heater system 85°F specify: ( ) 110VAC (X ) 220VAC

Power: 100/120/220/250 VAC (universal without temperature controlled heater systems)

( ) GPR-1600-W306 option general purpose panel mount 18.2x16x10”

Test

System start-up diagnostics satisfactory

Auto/manual range

Alarm relays activate/deactivate with changes in O2 concentration

Alarm bypass

Analog outputs: Signal output 4-20mA

Range ID: ( X ) 1-5 VDC or ( ) 5x relay contacts plus 1x common

Recovery from air to < 10 PPM in < 60 minutes

Baseline drift on zero gas < ± 2% FS over 24 hour period

Noise level < ± 1.0% FS

Span calibration gas value

Span adjustment within 10-50% FS

Peak to peak over/under shoot < 0.5% FS

Overall inspection for physic a l def ec t s

Options

Notes

2. Quality Control Certification

Date:

Pass

Sensor: ( ) GPR-12-333 PPM Oxygen Sensor

Accessories: Owner’s Manual

CABL-1008 Power Cord

( ) Stainless steel sensor housing, manual flow control and bypass valves, ¼” compression

Enclosure: ( X ) Std. panel mount (“T”) 7.5x10.8x12”; ( ) “TO” option 7.75x 7.75x12”

A-1146-10 PCB Assembly Main / Display Software V. ______
( X ) A-1146-10 PCB Power Supply / Interconnect, 1-5V Range ID

type fittings for sample inlet and vent
( ) Delete sample/bypass valve from above (T and TO options)

( ) Bezel for 19” rack mount 19x12x12” option
( ) GPR-1600-W option general purpose wall mount 12x12x8”

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Standard:

Manufacturing Procedure No. P-1057 Rev-1,

Published 1/1/1996 and related publications

Mfg. Item No.:

GPR-1600 Series

Description:

ppm Oxygen Analyzer

Serial No.:

___________________________

Customer:

___________________________

Purchase Order:

___________________________

Quantity:

1 of

Warranty Date:

12 months from ______________

Date:

______________

Place:

Pomona, CA

By print name:

Signature:

Title:

The certificate applies to the an al yzer specificall y o r d er ed to use componen t s f o r o xy gen s ervice. Check the QC of the
analyzer to ensure whether such an option was ordered.

Certificate of Cleaning

Oxygen Service

Compressed Gas Association,
Publication: G-4.1 Edition 4,
Title: Cleaning Equipment for Oxygen Service,

The undersigned war rants on behalf of Manufacturer that the product identified
above conforms t o the man ufactu ring, t esting and p ackagi ng crit eria set fo rth by
the ‘Standard’ specified above.

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Directives:

2006/95/EC Low Voltage
2004/108/EC Electromagnetic Compatibility

Standards:

EN 61010-1 Safety

EN 61326-1 Minimum Immunity Test

ISO 9001:2008

Compliance:

All applicable standards

Products:

General purpose online oxygen analyzers:

GPR-1600UHP series

GPR-1600MS series GPR-16MS series

GPR-1600 series GPR-16 series

GPR-1900 series GPR-19 series

GPR-2600 series GPR-26 series

GPR-2900 series GPR-29 series

GPR-3100 series GPR-31 series

GPR-1500 series GPR-15 series

GPR-2500 series GPR-25 series

GPR-1500AIS GPR-15A series

GPR-1800AIS GPR-18MS/18/28

GPR-2500AIS GPR-980 series

GPR-2800AIS GPR-35

General purpose portable oxygen analyzers:

GPR-1200MS series GPR-12MS series

GPR-1200 series GPR-12 series

GPR-1100 series GPR-11 series

GPR-1000

GPR-2000 series GPR-20 series

GPR-3000 series GPR-30 series

GPR-3500MO GPR-35MO

Intended Use:

Analyze oxygen concentration in a gas mixture in a non-explosive atmosphere.

Manufacturer:

Analytical Industries, Inc. dba Advanced Instruments, Inc.,.

2855 Metropolitan Place

Pomona, California 91767 USA

Tel: [phone], Fax: [phone]

e-mail: [e-mail]

Date:

September 15, 2013

Place:

Pomona, California 91767 USA

We hereby declare the above product meets the provisions of the directives and

Patrick Prindible
Vice President & QA Manager

Declaration of Conformity

standards specified. All supporting documents are retained on the premises of the
manufacturer and the notified body above.

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Advanced Instruments Inc.

3. Safety Guidelines

Safety

This section summ arizes t he basic precaut ions a pplica ble to all analy zers. Addition al prec aut ions spec ific to individu al
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 Manua l .

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

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. Observ e all precaut ion s and o peratin g ins truc tion s. Failur e to do so m ay r esult i n perso nal i njury or d amage
to the analyzer.

Heat: Situate and store the analyzer away from sources of heat.
Liquid and Object Entry: The analyz er should n ot be imm ersed in any liqu id. Care sh ould be taken so that liqui ds

are not spilled into and objects do not fall into the inside of the analyzer.
Handling: Do not use f or ce wh en usi ng th e sw itc he s an d kn obs. Bef or e movi n g your an alyz er be su re to di sc onn ect

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

such as the presence of hazardous voltages.

Maintenance

Serviceability: Except for repl acing the oxygen senso r, there are no part s inside the analyz er for the operator to
service.
Only trained personnel with the authorization of their supervisor should conduct mai nt e na nce.

Oxygen Sensor: DO NOT open the sensor. The sensor c ontains a c orrosiv e liquid electrol yte that could be harmful
if touched or ingeste d, refer to the Material Saf ety Data Sheet c ontained in th is Owner’s Man ual. Avoid co ntact with
any liquid or cr ystal typ e pow der in o r arou nd the sensor o r senso r hou sing, a s eith er cou ld be a fo rm of electrolyte.
Leaking sensors should be disposed of in accordance with local regulations.

Troubleshooting: Consult th e gui delin es in sectio n 8 fo r a dvice on the c ommo n oper atin g error s befo re c onc luding
that your analyzer is faulty. Do not attempt to service the analyzer b eyond those means described in this Owner ’s
Manual.

Do not attempt to make r epair s by yourse lf as th is will vo id th e warran ty, as det ailed by s ect ion 9, an d may result in
electrical shock, injury or damage. All other servicing should be referred to qualified service personnel.

Cleaning: T he analyzer sho uld be cleane d only as reco mmended b y the manufact urer. Wi pe off dust and di rt 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: En sure the gas stream co mposition of the application is c onsistent with the specificatio ns of
the analyzer/sen sor and review the application co nditions before initiating the installation. Con sult f actory to ensure
the sample is suitable for analysis.

Contaminant Gases: A gas scrubber and flo w indicat or wit h integral metering v alve ar e require d upstrea m of the
of the analyzer to remove interfering gases such as oxides of sulfur and nitrogen or hydrogen sulfide that can
produce false re adings, reduce th e expected life of the sensor and void sensor warran ty if not identifie d at time of
order placement. Consult factory for recommendations concerning the proper selection and installation of
scrubber/filter components.

Expected Sensor Life

With reference to the publish specificat ion located as the last p age of this manual, the exp ected life of all oxygen
sensors is pred icated on the basis of oxygen concentration (< 10,000 PPM), tempera ture (7 7°F/25°C) an d pressure
(1 atmosphere) in “normal” applications. As a rule of thumb senso r life is inversely prop ortional to changes in the
parameters. Deviations of the gas concentration and or temperature outside of the spec i f ications will af f ec t t he life of
the sensor. Avo id exposure to oxygen l evels above 1% (10,000 PPM) for hours at a time.

Failure to do so may result in damage to the sensor(s) as follows:

 GPR Series PPM sensors – red uc ed sen sor l ife an d loss o f lo w end sen siti vi ty wh en exposed con tinu ou sly to

20.9% oxygen; sensor will last approximately 6-8 months and may develop a low end offset > 1-2 PPM

 XLT Series PPM sensors - reduced sensor life and loss of low end sensitivity (XLT sensor exposed

continuously to the 20.9% O2 content of air will last approximately 7 days).

Accuracy & Calibration
Refer to section 5 Operation. The 0-25% Range is provided only for the purpose of air calibration which is
recommended on ly if span gas is not available. Br inging the analyzer bac k online after calibrat ion with the 20.9%
oxygen content of air, takes longer than calibrating the analyzer with a span gas, for example, 80 PPM oxygen.

Materials
Assemble the necessary zero, sample and span gases and optional components such as valves, coalescing or
particulate fil ters, and pum ps as dictated by th e application; stainless steel tubing is essen tial for maintaining the
integrity of the gas stream for PPM measurements.

Operating Temperature

The sample must be suffici ently coo led before i t enters th e analyzer and any opt ional co mponents. A c oiled 10 fo ot
length of ¼” stainless steel tubing is sufficient for cooling sample gases as high as 1,800ºF to ambient. The
maximum recommended operating temperatu re is 45º C. On an intermittent basis, unless the user is willin g t o accept
a reduction in exp ected sensor lif e – refer to analyz er specification , the analyzer may be o perated at 50 degr ee
temperatures above 25
temperature. As an example, if the analyzer is continuously operated at 35oC, the expected sensor life will be
reduced by ~25%.

Pressure and Flow

All electrochem ical oxygen senso r s respond to partial pressure changes in o xygen. The senso rs ar e equally capable o f
analyzing the oxyg en cont ent of a flo wing sample ga s stream o r monito ring the ox ygen concent ration in am bient air
(such as in a confined space in a control room or an open area such as a landfill or bio-pond).

Sample systems an d flo win g gas s ampl es are g ener ally r equ ir ed fo r appl icat ion s in vol ving o xy gen m easu remen t s in a
gas mixture. Fo r sub PPM measur ements, the use of stainless steel tubing and fittin gs is critica l to maintaining th e
integrity of the gas stream to be sampled. Further, the inlet sample pressure must always be higher than the
pressure at the outlet vent, which is normally at atmospheric pressure.

To analyze a gas stre am, th e gas must flow or be dr awn th rough t he senso r hou sing. The internal sampl e syst em of
the analyzer may include sam ple/bypass valves, shut off valve, a flow control (please che ck the QC sheet to ensure

o

C, the user can expect a reduction in sensor life of ~ 2.5% per degree increase in

o

C. At

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Advanced Instruments Inc.

the included s ample system) , a f low in dicato r and a st ainle ss st eel s ensor h ousin g with an o -ring seal to pr even t the
leakage of air int o the sensor housin g.

Inlet Pressure

Analyzers design ed for flowing samples under positive pressure or for samples at atm ospheric or slightly ne gative
atmospheres, are equi pped with bulkhead tube fitting co nnections at the rear of the analyzer. T he recommended
operating sample pressure is between 5-30 PSIG.

A pressure great er than 30 PS IG may preven t the solen oid valve s from opera ting proper ly (GPR-1600-AV
only). Further, the pres sure of Sample, Sp an and Zero gas must be within 10 PSIG for ease of control of
gas flow rate.

Outlet Pressure

In positive sample pressure applic ations, the sam ple must be vented to ambient air or in a vent with pressure les s
than the sample inlet pressure. If the sample is vented to a line at pressure above ambient, a back pressure
regulated set at no greater 1-2 PSIG must be installed on the downstream of the sensor to ensure a constant
pressure on the sensor.

Flow Rate

Flow rates of 1-5 SCFH caus e no appreci able ch ange in the o xygen rea ding. Howev er, f low rates a bove 5 SCFH may
generate a backpressure on the sensor and cause erroneous oxygen readings.

The analyzer is equ ipped wi th a flo w cont rol valve with a flow indicato r upstream of the sen sor housing. 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 th e sensor) to test the f low indicator when gas is
flowing to the senso r. R emovi ng your fing er (th e restr ictio n) gen erat es a vac uum o n the senso r and m ay
damage the sensor (voiding the sensor warranty).

Recommendations to avoid erroneous oxygen readings and damaging the sensor:

 Do not place your finger over the vent (it pressurizes the sensor) to test the flow indicator when gas is flowing to

the sensor. Removing your finger (the restriction) generates a vacuum on the sensor and may damage the
sensor.

 Assure there are no restrictions in the sample or vent lines.
 Avoid excessive flow rate, flow rate above 5 SCFH may generate backpressure on the sensor.
 Avoid sudden releases of backpressure that can severely damage the sensor.
 Avoid the co llection of liqu ids or particul ates on the sensor, they block the di ffusion of oxygen into the senso r -

wipe away any liquid and particulate with a damped cloth only.

Moisture & Particulates

Installation of a suitable coalescing and or particulate filter is required to remove liquid condensates, and/or
particulates fro m the sample gas to prevent clo gging of the sampling system . Moisture and/or particulat es do not
necessarily dam age the sensor itself but collection of moisture/ partic ulat e on the sensin g sur face c an bloc k or inh ibit
the diffusion of sam ple gas into th e sen so r thus re su lt i n g in a redu ction of sensor signal output – an d t h e appearance
of a sensor failu re. Consult factory for recommendations concern ing the proper selection of coalescing/particulate
filters.

Moisture and/or particulates collect ed at the sensor may be removed by either blowing on the sensing su rface or
gently wiping the sensing surface with damp cloth.

Caution: Minim ize the e xposure o f sensor t o air dur ing thi s cleanin g process. Air c alibrat ion follo wed by
purging with zero or a ga s with a lo w PPM oxygen c oncent ration is r ecommen ded follo wing th e cleaning
process.

Mounting

The standard analyzer is ap proved for indoor use only. Outdoor use requi res optional enclosures, c onsult factory.
Mount analyzer as recommended in this manual.

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The analyzer is configured for panel mounting and requires a 7.5x10.8” (T configuration) cutout with 4 holes for the
analyzer’s front panel. Optional configurations include a panel mount (TO configuration) with 7.75x7.75” cutout; 19”
bezel for rack mounting either the T or TO; 12x12x8” wall mount enclosure (GPR-1600W) and 18.2x16x10” panel
mount configuration (GPR-1600W-306).

Gas Connections

Sample Inlet an d Sample Vent gas lines for PPM analysis r equire 1/8” or ¼ ” stainless steel compr essi o n f ittings; hard
plastic tubing with a low gas permeability factor may be used for measurements of oxygen above 1000 PPM.

Power

Supply power t o the analyzer on ly as rated by the specific ation or markings on th e analyzer enclosure.
The wiring that connects the analyzer to the power source should be installed in accordance with
recognized elec trical standard s. Ensure that the analyzer enclosure is properly grounded and meet s the
requirements of recommended local electrical standards.

Never yank wiring to remove it from a terminal connection.

AC powered analyzers consume a maximum of 30 watts, without the optional heaters. With optional
110 VAC or 220 VAC heaters installed, the maximum power consumption is 230 watts.

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4. Features & Specifications

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5. Operation

5.1 Principle of Operation

The GPR-1600 Oxygen Analy zers incorpor ates a variety of PPM range advanc ed galvanic f uel cell type senso rs. The
analyzer is configured for panel mounting and requires a 7.5x10.8” (T configuration) cutout with 4 holes for the
analyzer’s front panel. Optional configurations include a panel mount (TO configuration) 7.75x7.75” with cutout; 19”
bezel for rack mounting either the T or TO; 12x12x8” wall mount enclosure (GPR-1600W); 18.2x16x10” panel mount
configuration (GPR-1600W-306) using the wall mount enclosure. Contact the factory for additional information on
options. All configurations are tested and calibrated by the manufacturer prior to shipment.

The GPR-1600 series analyzers and sensors conform to CE standards and are manufactured under a Quality
Assurance System, certified by an independent agency, in accordance with ISO 9001:2004 standards.

Advance Galvanic Sensor Technology

All galvanic sen sors fu nction on the sam e principl e and ar e specific to oxygen. The y measu re the parti al pre ssure of
oxygen ranging from low PPM to 100 % levels in inert gases, gas eous hydr ocarbons, helium , hydrogen, mixed gases
and acid gas st reams. Oxygen, the fuel for this electrochemical transducer, diffuses into the sensor and

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 measuring ranges and

remains virtually constant over its useful life. The sensor req u ir es n o m ain t en an ce and is easily an d safely replaced at
the end of its useful life.

Proprietary adv ancements in the design and ch emistry add signif icant advantages t o an extremely v ersatile oxygen
sensing technology. Sensors for low PPM analysis rec over fr om air to PPM levels in minu tes, exhi bit longer life, offer
extended operating range of -20°C to 50°C, have excellent compatibility with CO
sensors) and reliable quality thus giving the user a significant advantage over other competitors. Other
advancements inc lude extendi ng the expec ted life of o ur new generation o f percentage r ange sensor s to five to ten
years with fast er response times and gr eater stability. Another si gnificant development involves the first galvanic
oxygen sensor cap able of measuring o xygen purity co ntinuously and expanded operating temperature r ange from ­40°C to 50°C. Consult factory for selection of sensors for your specific applications.

and acid gases (XLT series

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Advanced Instruments Inc.

5.2 Electronics

The signal generated by the sensor is processed by state of the art low powered micro-processor based digital
circuitry. T he first st age amplif ies and converts the electrical c urrent into voltage signal. The seco nd stage el imin ates
the low frequenc y noise. The third stag e employs a high frequency f ilter and compensates f or the sensor’s signal
output variations caused by ambient tem perature variat io ns. The result is a very stable sensor signal.

Sensor’s response time of 90 % o f a “step change” is less tha n 10 -30 seconds (actu al experience ma y var y due to the
integrity of sam ple line connecti ons, dead volume and flo w rate selected) o n all ranges under am bient monitoring
conditions. Sensitivity is typically 0.5% of full scale of the lowest range of analysis.

Additional features of the micro-processor based electro nics inc lude manual or au to ranging, auto-zero and auto -cal,
isolated 4-20mA sign al fo r sig nal out put, optional 4-20 mA as range ID, separ at e rel ay co ntac ts rat ed 3 0 VDC m ax @
1A or 110/220 VAC @ 5A are provided for the alarm feature. Optional range ID contacts are rated at 30 VDC @1A.

Whenever the analy zer is span c alibrated, a uniqu e algorithm predicts and displays a message indicatin g a ‘weak
sensor’ (if the sensor output has fallen below a certain level), suggesting the sensor be replaced in the near future.

5.3 Sample System

For accurate measu rements, the sam ple gas must be prop erly presented t o the sensor. In stan dard form, the GPR­1600 is equipped with a sample system that complements the performance capabilities of the advanced oxygen
sensor.

The integral sam ple syst em of the anal yzer is shown sc hematicall y below ( please ch eck the QC sheet in th is manual
to ensure the analyzer is equipped with the sample system ordered).

Advanced Instrum ents Inc. offers a full l ine of sample ha ndling, c onditioni ng and experti se to meet your application
requirements. Contact us at 909-392-6900 or e-mail us at

[e-mail] for your specific requirements.

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5.4 Accuracy Overview

Single Point Calibration: As previously described
the galvanic oxygen sensor generates an electrical
current proportional to the oxygen concentration in
the sample gas. I n the ab senc e of ox ygen the senso r
exhibits an absolute zero, e.g. the sensor does not
generate a cu rrent output in the absen ce of oxygen.
Given the 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'. For best accuracy, the
pressure of the sam pl e g as and that of the calibration
gas must be the same (in reality within 2-5 psi) so
that when the SAM PLE/S PAN gas es are switc hed, th e
gas flow rate would not drastically change.

Temperature: The rate at which oxygen molecules diffuse into th e sensor is controlled by a T eflon membrane
otherwise known as an 'oxygen diffusion limiting barrier. The fact that all diffusion processes are temperature
sensitive, the senso r's electrical o utput also varie s with temper ature. This var iation is relat ively constant (2.5% per
ºC chan ge in temperature). A tem perature compensation c ircuit employing a thermistor offsets this effect with an
accuracy of +
that is virtually independent of small ambient temperature variation. To mini mize error in oxygen m easurement , the
calibration of th e analyzer shou ld be carried out as c lose as possible to t he temperature dur ing sampling. A small
temperature variation of ~10º F will produce < 2% error.

Accuracy:

1) 'Percent of reading errors', illustrated by Graph A below, such as +
compensation circuit due to the tolerances of the resistors and thermistor.

2) 'Percent of full scale errors', illustrated by Graph B, such as +
tolerances in th e electro nic compon ents, which are r eally mini mal due to tod ay's technology and the fact that other
errors are 'spanned out' during calibration.

Graph C illustrat es these 'w orse case' s pecificatio ns that are ty pically use d to develo p an analyzer's overall accuracy
statement of < 1% of full scale at constant temperature or < 5% o ver the operati ng tem perature range. QC testing
is typically < 1% prior to shipment.

Example 1: As illustrat ed by Graph A any error dur ing a span adju stment, e.g., at 20.9% (air) of full scale range
would be multipl ied b y a f ac tor of 4.78 (100/20.9) when used for measurem ent s of 95-100 % oxygen concentrations.
Conversely, an error during span adjustment at 100% of full scale range will be reduced proportionately for
measurements of lower oxygen concentrations. Refer to the Calibration section for additional details.

5% or better (over th e operating temper ature range of th e analyzer) and generates an o utput signal

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

5% inherited error in the temperature

1-2% linearity errors generally associated with

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