Teledyne Analytical Instruments 3000PA-EU User manual

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Percent Oxygen AnalyzerPercent Oxygen Analyzer
Percent Oxygen AnalyzerPercent Oxygen Analyzer
Percent Oxygen Analyzer
Teledyne Analytical Instruments
OPERATING INSTRUCTIONS FOR
Model 3000PA-EU
Percent Oxygen Analyzer
HIGHLY TOXIC AND OR FLAMMABLE LIQUIDS OR GASES MAY BE PRESENT IN THIS
MONITORING SYSTEM.
PERSONAL PROTECTIVE EQUIPMENT MAY BE REQUIRED WHEN SERVICING THIS SYSTEM.
HAZARDOUS VOLTAGES EXIST ON CERTAIN COMPONENTS INTERNALLY WHICH MAY PER-
SIST FOR A TIME EVEN AFTER THE POWER IS TURNED OFF AND DISCONNECTED.
ONLY AUTHORIZED PERSONNEL SHOULD CONDUCT MAINTENANCE AND/OR SERVICING.
BEFORE CONDUCTING ANY MAINTENANCE OR SERVICING CONSULT WITH AUTHORIZED
SUPERVISOR/MANAGER.
DANGER
P/NM66317
2/02/2016

Use and Disclosure of Data
Information contained herein is classified as EAR99 under the
U.S. Export Administration Regulations.
Export, reexport or diversion contrary to U.S. law is prohibited.



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Model 3000PModel 3000P
Model 3000PModel 3000P
Model 3000PAA
AA
A
Teledyne Analytical Instruments
Copyright © 2016 Teledyne Analytical Instruments
All Rights Reserved. No part of this manual may be reproduced, transmitted, tran-
scribed, stored in a retrieval system, or translated into any other language or computer
language in whole or in part, in any form or by any means, whether it be electronic,
mechanical, magnetic, optical, manual, or otherwise, without the prior written consent of
TeledyneAnalyticalInstruments,16830ChestnutStreet,CityofIndustry,CA 91748.
Warranty
This equipment is sold subject to the mutual agreement that it is warranted by us free
from defects of material and of construction, and that our liability shall be limited to
replacing or repairing at our factory (without charge, except for transportation), or at
customer plant at our option, any material or construction in which defects become
apparent within one year from the date of shipment, except in cases where quotations or
acknowledgments provide for a shorter period. Components manufactured by others bear
the warranty of their manufacturer. This warranty does not cover defects caused by wear,
accident, misuse, neglect or repairs other than those performed by Teledyne or an autho-
rized service center. We assume no liability for direct or indirect damages of any kind and
the purchaser by the acceptance of the equipment will assume all liability for any damage
which may result from its use or misuse.
We reserve the right to employ any suitable material in the manufacture of our
apparatus, and to make any alterations in the dimensions, shape or weight of any parts, in
so far as such alterations do not adversely affect our warranty.
ImportantNotice
This instrument provides measurement readings to its user, and serves as a tool by
which valuable data can be gathered. The information provided by the instrument may
assist the user in eliminating potential hazards caused by his process; however, it is
essential that all personnel involved in the use of the instrument or its interface, with the
process being measured, be properly trained in the process itself, as well as all instrumenta-
tion related to it.
The safety of personnel is ultimately the responsibility of those who control process
conditions. While this instrument may be able to provide early warning of imminent danger,
it has no control over process conditions, and it can be misused. In particular, any alarm or
control systems installed must be tested and understood, both as to how they operate and
as to how they can be defeated. Any safeguards required such as locks, labels, or redun-
dancy, must be provided by the user or specifically requested of Teledyne at the time the
order is placed.
Therefore, the purchaser must be aware of the hazardous process conditions. The
purchaser is responsible for the training of personnel, for providing hazard warning
methods and instrumentation per the appropriate standards, and for ensuring that hazard
warning devices and instrumentation are maintained and operated properly.
Teledyne Analytical Instruments, the manufacturer of this instrument, cannot
accept responsibility for conditions beyond its knowledge and control. No statement
expressed or implied by this document or any information disseminated by the manufactur-
er or its agents, is to be construed as a warranty of adequate safety control under the
user’s process conditions.

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Teledyne Analytical Instruments
SpecificModelInformation
Theinstrumentforwhichthismanualwassuppliedmayincorporateoneor
moreoptionsnotincludedwiththestandardinstrument.Commonlyavailable
optionsarelistedbelow,withcheckboxes.Anythatareincorporatedinthe
instrumentforwhichthismanualissuppliedareindicatedbyacheckmarkinthe
box.
InstrumentSerialNumber _______________________
includesthefollowingoptions:
❑❑
❑❑
❑3000PA-C: Inadditiontoallstandardfeatures,thismodelalsohas
separateportsforzeroandspangases,andbuilt-in
controlvalves.Theinternalvalvesareentirelyunderthe
controlofthe3000PAelectronics,toautomatically
switchbetweengasesinsynchronizationwiththe
analyzer’soperations
❑❑
❑❑
❑3000PA-S: Inmodelswiththisoption,allwettedpartsaremade
from316stainlesssteel.
❑❑
❑❑
❑3000PA-M: Inmodelswiththisoption,the4-20mAAnalogCurrent
outputisactive.(Inthestandardunits,itisnotactive.)
❑❑
❑❑
❑19" Rack Mnt: The19"RelayRackMountunitsareavailablewith
eitheroneortwo3000seriesanalyzersinstalledona
19"panel,andreadytomountinastandardrack.
❑❑
❑❑
❑Cell Class: ___________________ See Maintenance for Specs.
Enter Class Designation.

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Model 3000PModel 3000P
Model 3000PModel 3000P
Model 3000PAA
AA
A
Teledyne Analytical Instruments
Model3000PA-EU complieswith allof therequirements ofthe
Commonwealth of Europe (CE) for Radio Frequency Interference,
ElectromagneticInterference(RFI/EMI),andLowVoltageDirective
(LVD).
Thefollowing International Symbolsareused throughout theInstruc-
tion Manual for your visual and immediate warnings and when you
have to attend CAUTION while operating the instrument:
STAND-BY, Instrument is on Stand-by,
but circuit is active
GROUND
Protective Earth
CAUTION, The operator needs to refer to the manual
for further information. Failure to do so may
compromise the safe operation of the equipment.
CAUTION, Risk of Electric Shock
COMBUSTIBLE GAS USAGE WARNING
DANGER
This is a general purpose instrument designed for usage in a
nonhazardous area. It is the customer's responsibility to ensure
safety especially when combustible gases are being analyzed
since the potential of gas leaks always exist.
The customer should ensure that the principles of operating of
this equipment is well understood by the user. Misuse of this
product in any manner,tampering with its components,or unau-
thorized substitution of any component may adversely affect the
safety of this instrument.
Since the use of this instrument is beyond the control of
Teledyne,no responsibility byTeledyne,its affiliates,and agents
for damage or injury from misuse or neglect of this equipment is
implied or assumed.

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Teledyne Analytical Instruments
Table of Contents
1 Introduction
1.1 Overview........................................................................ 1-1
1.2 Typical Applications ....................................................... 1-1
1.3 Main Features of the Analyzer ....................................... 1-1
1.4 Model Designations ....................................................... 1-2
1.5 Front Panel (OperatorInterface) ..................................... 1-3
1.6 Rear Panel (Equipment Interface).................................. 1-5
2 OperationalTheory
2.1 Introduction .................................................................... 2-1
2.2 Micro-Fuel Cell Sensor .................................................. 2-1
2.2.1 Principles of Operation ............................................ 2-1
2.2.2 Anatomy of a Micro-Fuel Cell .................................. 2-2
2.2.3 Electrochemical Reactions ...................................... 2-3
2.2.4 The Effect of Pressure.............................................. 2-4
2.2.5 Calibration Characteristics ...................................... 2-4
2.2.6 Micro-Fuel Cell “Class” .......................................... 2-5
2.3 Sample System.............................................................. 2-6
2.4 Electronics and Signal Processing ................................ 2-8
3 Installation
3.1 Unpacking the Analyzer................................................. 3-1
3.2 Mounting the Analyzer ................................................... 3-1
3.3 Rear Panel Connections................................................ 3-2
3.3.1 Gas Connections ................................................... 3-3
3.3.2 Electrical Connections........................................... 3-4
3.3.2.1 Primary Input Power....................................... 3-4
3.3.2.2 50-Pin Equipment Interface Connector.......... 3-5
3.3.2.3 RS-232 Port ................................................... 3-9
3.4 Installing the Micro-Fuel Cell .........................................3-10
3.5 Testing the System.........................................................3-12
4 Operation
4.1 Introduction .................................................................... 4-1
4.2 Using the Data Entry and Function Buttons ................... 4-2
4.3 The System Function ..................................................... 4-3
4.3.1 Setting the Display................................................. 4-4
4.3.2 Setting up an Auto-Cal........................................... 4-5
4.3.3 Password Protection .............................................. 4-5
4.3.3.1 Entering the Password................................... 4-6

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4.3.3.2 Installing or Changing the Password ............. 4-7
4.3.4 Logout.................................................................... 4-8
4.3.5 System Self-Diagnostic Test .................................. 4-9
4.3.6 Version Screen ...................................................... 4-9
4.4 The
Zero Span Functions .............................................. 4-10
4.4.1 Cell Failure ............................................................ 4-10
4.4.2 Span Cal................................................................ 4-11
4.4.2.1 Auto Mode Spanning ..................................... 4-11
4.4.2.2 Manual Mode Spanning................................. 4-12
4.5 The Alarms Function...................................................... 4-12
4.6 The
Range Function ...................................................... 4-15
4.6.1 Setting the Analog Output Ranges......................... 4-15
4.6.2 Autoranging Analysis............................................. 4-16
4.6.3 Fixed Range Analysis............................................ 4-16
4.7 The Analyze Function.................................................... 4-17
4.8 Signal Output ................................................................. 4-17
Maintenance
5.1 Routine Maintenance..................................................... 5-1
5.2 Cell Replacement .......................................................... 5-1
5.2.1 Storing and Handling Replacement Cells ............... 5-1
5.2.2 When to Replace a Cell........................................... 5-2
5.2.3 Removing the Micro-Fuel Cell ................................. 5-3
5.2.4 Installing a New Micro-Fuel Cell.............................. 5-5
5.2.5 CellWarranty ........................................................... 5-5
5.3 Fuse Replacement......................................................... 5-6
5.4 System Self Diagnostic Test........................................... 5-6
5.5 Major Internal Components............................................ 5-7
5.6 Cleaning ........................................................................ 5-8
5.7 Troubleshooting ............................................................. 5-9
Appendix
A-1 Model 3000PA Specifications ........................................ A-1
A-2 Recommended 2-Year Spare Parts List ......................... A-3
A-3 Drawing List................................................................... A-4
A-4 19-Inch Relay Rack Panel Mount................................... A-4
A-5 Application Notes on Restrictors, Pressures & Flow...... A-5
A-5 Zero Functions............................................................... A-8

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Percent Oxygen Analyzer Introduction 1
Teledyne Analytical Instruments
Introduction
1.1 Overview
The Teledyne Analytical Instruments Model 3000PA Percent Oxygen
Analyzer is a versatile microprocessor-based instrument for detecting the
percentage of oxygen in a variety of background gases. This manual covers
only the Model 3000PA General Purpose flush-panel and/or rack-mount
units with CE mark. These units are for indoor use in a nonhazardous
environment.
1.2 TypicalApplications
A few typical applications of the Model 3000PA are:
• Monitoring inert gas blanketing
• Airseparation andliquefaction
• Chemicalreactionmonitoring
• Semiconductormanufacturing
• Petrochemical process control
• Qualityassurance
• Gasanalysiscertification.
1.3 Main Features of the Analyzer
The Model 3000PA Percent Oxygen Analyzer is sophisticated yet
simple to use. The main features of the analyzer include:
• A 2-line alphanumeric display screen, driven by microprocessor
electronics, that continuously prompts and informs the operator.
• High resolution, accurate readings of oxygen content from low
percent levels through 100 %. Large, bright, meter readout.

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• Advanced Micro-Fuel Cell, designed for percent oxygen
analysis. Several options are available.
• Versatile analysis over a wide range of applications.
• Microprocessor based electronics: 8-bit CMOS microprocessor
with 32 kB RAM and 128 kB ROM.
• Three user definable output ranges (from 0-1% through
0-100 %) allow best match to users process and equipment.
• Air-calibration range for convenient spanning at 20.9 %.
• Auto Ranging allows analyzer to automatically select the proper
preset range for a given measurement. Manual override allows
the user to lock onto a specific range of interest.
• Two adjustable concentration alarms and a system failure alarm.
• Extensive self-diagnostic testing, at startup and on demand,
with continuous power-supply monitoring.
• CE Compliance.
• RS-232 serial digital port for use with a computer or other
digital communication device.
• Analog outputs for percent-of-range and for range
identification. 0–1 V dc. (Isolated 4–20 mA dc optional)
• Convenient and versatile, steel, flush-panel or rack-mountable
case with slide-out electronics drawer.
1.4 ModelDesignations
3000PA: Standard model.
3000PA-C: In addition to all standard features, this model also has
separate ports for zero and span gases, and built-in control
valves. The internal valves are entirely under the control of
the 3000PA electronics, to automatically switch between
gases in synchronization with the analyzer’s operations.
3000PA-M: This model has current output signals (4-20 mA) for
percent-of-range and range ID, in addition to voltage
outputs.
3000PA-S: A Stainless Steel Probe and Probe Holder are used in this
model, for use where resistance to corrosion is important.

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Teledyne Analytical Instruments
3000PA-V: Gas flow through the cell block in this model is driven by
vacuum downstream from the cell block, instead of by
pressure upstream. The internal restrictor is located
downstream from the cell block to support this
configuration. All other standard features are present in this
model.
All of the above options are available in combination. For example,
the -C and -V options are combined as Model 3000PA-C-V.
1.5 Front Panel (Operator Interface)
The standard 3000PA is housed in a rugged metal case with all con-
trols and displays accessible from the front panel. See Figure 1-1. The
front panel has thirteen buttons for operating the analyzer, a digital meter,
an alphanumeric display, and a window for viewing the sample flowmeter.
Function Keys: Six touch-sensitive membrane switches are used to
change the specific function performed by the analyzer:
•Analyze Perform analysis for oxygen content of a sample gas.
Figure 1-1: Model 3000PA Front Panel

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Teledyne Analytical Instruments
•System Perform system-related tasks (described in detail in
chapter 4, Operation.).
•Span Span calibrate the analyzer.
•Zero Zero calibrate the analyzer.
•Alarms Set the alarm setpoints and attributes.
•Range Set up the 3 user definable ranges for the instrument.
Data Entry Keys: Six touch-sensitive membrane switches are used to
input data to the instrument via the alphanumeric VFD display:
•Left & Right Arrows Select between functions currently
displayed on the VFD screen.
•Up & Down Arrows Increment or decrement values of
functions currently displayed.
•Enter Moves VFD display on to the next screen in a series.
If none remains, returns to the Analyze screen.
•Escape Moves VFD display back to the previous screen in a
series. If none remains, returns to the Analyze screen.
Digital Meter Display: The meter display is a LED device that
produces large, bright, 7-segment numbers that are legible in any lighting
environment. It produces a continuous readout from 0-100 %. It is accurate
across all ranges without the discontinuity of analog range switching.
Alphanumeric Interface Screen: The VFD screen is an easy-to-use
interface from operator to analyzer. It displays values, options, and
messages that give the operator immediate feedback.
Flowmeter: Monitors the flow of gas past the sensor. Readout is 0.2
to 2.4 standard liters per minute (SLPM).
 Standby Button: The Standby turns off the display and outputs,
but circuitry is still operating.
CAUTION: The power cable must be unplugged to fully
disconnect power from the instrument. When
chassis is exposed or when access door is open
and power cable is connected, use extra care to
avoid contact with live electrical circuits.
Access Door: To provide access to the Micro-Fuel Cell and the front
panel electronics, the front panel swings open when the latch in the upper
right corner of the panel is pressed all the way in with a narrow gauge tool.

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Teledyne Analytical Instruments
Accessing the other circuit board requires unfastening the rear panel
screws and sliding the electronics drawer out of the case.
1.6 Recognizing Difference Between LCD & VFD
LCD has GREEN background with BLACK characters. VFD has
DARK background with GREEN characters. In the case of VFD - NO
CONTRAST ADJUSTMENT IS NEEDED.
1.7 Rear Panel (Equipment Interface)
The rear panel, shown in Figure 1-2, contains the gas and electrical
connectors for external inlets and outlets. The Zero and Span gas connec-
tors, and the Current signal outputs are optional and may not appear on
your instrument. The connectors are described briefly here and in detail in
the Installation chapter of this manual.
Figure 1-2: Model 3000PA Rear Panel
•Power Connection Universal AC power source.
•Gas Inlet and Outlet One inlet (must be externally valved)
and one exhaust out. Three inlets when
“C” option is ordered.
•9-Pin RS-232 Port Serial digital concentration signal
output and control input.
• 50-Pin Equipment Interface Port

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Teledyne Analytical Instruments
•Analog Outputs 0-1 V dc concentration output, plus
0-1 V dc range ID.
•Alarm Connections 2 concentration alarms and 1 system
alarm.
•Remote Valve Used in the 3000PA for controlling
external solenoid valves only.
•Remote Span/Zero Digital inputs allow external control
of analyzer calibration. (See Note,
below.)
•Calibration Contact To notify external equipment that
instrument is being calibrated and
readings are not monitoring sample.
•Range ID Contacts Four separate, dedicated, range relay
contacts. Low, Medium, High, Cal.
•Network For future expansion. Not
implemented at this printing.
Optional:
•Calibration Gas Ports Separate fittings for zero, span and
sample gas input, and internal valves
for automatically switching the gases.
• Current Signal Output Additional isolated 4-20 mA dc plus
4-20 mA dc range ID.
Note: If you require highly accurate Auto-Cal timing, use external
Auto-Cal control where possible. The internal clock in the
Model 3000PA is accurate to 2-3 %. Accordingly, internally
scheduled calibrations can vary 2-3 % per day.

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Operational Theory
2.1 Introduction
Theanalyzer is composed of three subsystems:
1. Micro-FuelCellSensor
2. SampleSystem
3. ElectronicSignal Processing, DisplayandControl
The sample system is designed to accept the sample gas and transport it
throughtheanalyzer withoutcontaminatingor altering thesampleprior to
analysis.TheMicro-FuelCellisan electrochemical galvanicdevicethat
translatesthe amountof oxygenpresent inthe sampleinto anelectrical
current.Theelectronicsignalprocessing,displayandcontrolsubsystem
simplifiesoperationoftheanalyzerandaccuratelyprocessesthesampled
data.Themicroprocessorcontrolsallsignalprocessing,input/outputand
displayfunctionsfortheanalyzer.
2.2 Micro-Fuel Cell Sensor
2.2.1 Principles of Operation
The oxygen sensor used in the Model 3000P series is a Micro-Fuel Cell
designedand manufactured byAnalyticalInstruments. Itisa sealedplastic
disposableelectrochemicaltransducer.
The active components of the Micro-Fuel Cell are a cathode, an anode,
and the 15% aqueous KOH electrolyte in which they are immersed. The cell
convertsthe energy from a chemical reaction into an electricalcurrent inan
externalelectricalcircuit.Itsaction issimilartothatofabattery.
There is, however, an important difference in the operation of a battery
as compared to the Micro-Fuel Cell: In the battery, all reactants are stored
within the cell, whereas in the Micro-Fuel Cell, one of the reactants (oxygen)
comes from outside the device as a constituent of the sample gas being

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Teledyne Analytical Instruments
analyzed. The Micro-Fuel Cell is therefore a hybrid between a battery and a
true fuel cell. (All of the reactants are stored externally in a true fuel cell.)
2.2.2 Anatomy of a Micro-Fuel Cell
The Micro-Fuel Cell is a cylinder only 1¼ inches in diameter and 1
inch thick. It is made of extremely inert plastic, which can be placed confi-
dentlyinpracticallyanyenvironmentorsample stream.Itiseffectively
sealed, although one end is permeable to oxygen in the sample gas. The
other end of the cell is a contact plate consisting of two concentric foil rings.
The rings mate with spring-loaded contacts in the sensor block assembly and
provide the electrical connection to the rest of the analyzer. Figure 2-1
illustratestheexternalfeatures.
Figure 2-1: Micro-Fuel Cell
Refer to Figure 2-2, Cross Section of a Micro-Fuel Cell, which illus-
tratesthefollowinginternaldescription.
Figure 2-2. Cross Section of a Micro-Fuel Cell (not to scale)
At the top end of the cell is a diffusion membrane of Teflon, whose
thicknessisveryaccuratelycontrolled.Beneath the diffusionmembranelies

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the oxygen sensing element—the cathode—with a surface area almost 4 cm2.
The cathode has many perforations to ensure sufficient wetting of the upper
surfacewith electrolyte,and it is plated with an inert metal.
The anode structure is below the cathode. It is made of lead and has a
proprietarydesign which ismeant to maximizetheamount ofmetalavailable
forchemicalreaction.
At the rear of the cell, just below the anode structure, is a flexible
membranedesigned to accommodatetheinternal volume changesthatoccur
throughoutthe life ofthe cell. Thisflexibility assures thatthe sensing mem-
braneremainsinits proper position,keepingtheelectricaloutputconstant.
The entire space between the diffusion membrane, above the cathode,
andthe flexiblerear membrane, beneaththe anode,is filled withelectrolyte.
Cathode and anode are submerged in this common pool. They each have a
conductor connecting them to one of the external contact rings on the contact
plate, which is on the bottom of the cell.
2.2.3 Electrochemical Reactions
The sample gas diffuses through the Teflon membrane. Any oxygen in
the sample gas is reduced on the surface of the cathode by the following
HALF REACTION:
O2+ 2H2O + 4e––
––
–
→4OH––
––
–(cathode)
(Four electrons combine with one oxygen molecule—in the presence of
waterfromthe electrolyte—toproducefour hydroxyl ions.)
When the oxygen is reduced at the cathode, lead is simultaneously
oxidized at the anode by the following HALF REACTION:
Pb + 2OH––
––
–→ Pb+2 + H2O + 2e––
––
–(anode)
(Two electrons are transferred for each atom of lead that is oxidized.
Therefore it takes two of the above anode reactions to balance one cathode
reactionandtransferfourelectrons.)
The electrons released at the surface of the anode flow to the cathode
surface when an external electrical path is provided. The current is propor-
tional to the amount of oxygen reaching the cathode. It is measured and used
todetermine theoxygen concentration in the gas mixture.
The overall reaction for the fuel cell is the SUM of the half reactions
above, or:
2Pb + O2→2PbO

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(These reactions will hold as long as no gaseous components capable of
oxidizinglead—suchasiodine,bromine,chlorineandfluorine—arepresent
inthesample.)
The output of the fuel cell is limited by (1) the amount of oxygen in the
cell at the time and (2) the amount of stored anode material.
In the absence of oxygen, no current is generated.
2.2.4 The Effect of Pressure
In order to state the amount of oxygen present in the sample as a per-
centage of the gas mixture, it is necessary that the sample diffuse into the cell
underconstantpressure.
If the total pressure increases, the rate that oxygen reaches the cathode
throughthe diffusingmembranewill alsoincrease. The electrontransfer, and
therefore the external current, will increase, even though the oxygen concen-
tration of the sample has not changed. It is therefore important that the
samplepressureatthe fuel cell(usuallyventpressure)remainconstant
betweencalibrations.
2.2.5 Calibration Characteristics
Given that the total pressure of the sample gas at the surface of the
Micro-FuelCell input isconstant,a convenientcharacteristicofthe cellis
thatthe currentproduced in anexternal circuitis directlyproportional to the
rate at which oxygen molecules reach the cathode, and this rate is directly
proportional to the concentration of oxygen in the gaseous mixture. In other
words it has a linear characteristic curve, as shown in Figure 2-3. Measuring
circuitsdonothave to compensatefornonlinearities.
In addition, since there is zero output in the absence oxygen, the charac-
teristic curve has close to an absolute zero. In the percent ranges, the cell
itself does not need to be zeroed. In practical application zeroing is still used
tocompensate forzero offsets inthe electronics.(The electronicsiszeroed
automaticallywhen theinstrument poweristurned on.)

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Figure 2-3. Characteristic Input/Output Curve for a Micro-Fuel Cell
2.2.6 Micro-Fuel Cell “Class”
TBEmanufacturesMicro-Fuel Cellswithavariety ofcharacteristicsto
give the best possible performance for any given sample conditions. A few
typicalMicro-FuelCells are listedbelowwiththeir typical useandelectrical
specifications.
2.2.6.1 Class A-3 Cell
The class A-3 cell is for use in applications where it is exposed continu-
ously to carbon dioxide concentrations between 1 % and 100 % in the
samplegas.
Nominal output in air is 0.20 mA, and 90 % response time is 45 s.
Expected life in flue gas is 8 months.
2.2.6.2 Class A-5 Cell
The class A-5 cell is for use in applications where it is exposed intermit-
tently to carbon dioxide concentrations up to 100 % in the sample gas.