SIST EN IEC 61207-2:2019
(Main)Expression of performance of gas analyzers - Part 2: Measuring oxygen in gas utilizing high-temperature electrochemical sensors (IEC 61207-2:2019)
Expression of performance of gas analyzers - Part 2: Measuring oxygen in gas utilizing high-temperature electrochemical sensors (IEC 61207-2:2019)
Applies to gas analyzers using high temperature electrochemical sensors for measurement of oxygen in gas. Applies to both 'in situ' and extractive analyzers installed indoors or outdoors.
Angabe zum Betriebsverhalten von Gasanalysatoren - Teil 2: Sauerstoffmessung in Gas unter Verwendung von elektrochemischen Hochtemperatur-Sensoren (IEC 61207-2:2019)
Expression des qualités de fonctionnement des analyseurs de gaz - Partie 2: Mesure de l'oxygène contenu dans le gaz en utilisant des capteurs électrochimiques à haute température (IEC 61207-2:2019)
S'applique aux analyseurs de gaz utilisant des capteurs électrochimiques à haute température pour la mesure de l'oxgène contenue dans les gaz. S'applique aux analyseurs Ôin-situ' et extractif installés à l'intérieur ou à l'extérieur.
Izražanje lastnosti analizatorjev plina - 2. del: Merjenje kisika v plinu z uporabo visokotemperaturnih elektrokemijskih senzorjev
Uporablja se za analizatorje plina z uporabo visokotemperaturnih elektrokemijskih senzorjev za merjenje kisika v plinu. Uporablja se za »in situ« in ekstraktivne analizatorje, ki so postavljeni v notranjih prostorih ali na prostem.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN IEC 61207-2:2019
01-november-2019
Nadomešča:
SIST EN 61207-2:1998
Izražanje lastnosti analizatorjev plina - 2. del: Merjenje kisika v plinu z uporabo
visokotemperaturnih elektrokemijskih senzorjev
Expression of performance of gas analyzers - Part 2: Measuring oxygen in gas utilizing
high-temperature electrochemical sensors (IEC 61207-2:2019)
Angabe zum Betriebsverhalten von Gasanalysatoren - Teil 2: Sauerstoffmessung in Gas
unter Verwendung von elektrochemischen Hochtemperatur-Sensoren (IEC 61207-
2:2019)
Expression des qualités de fonctionnement des analyseurs de gaz - Partie 2: Mesure de
l'oxygène contenu dans le gaz en utilisant des capteurs électrochimiques à haute
température (IEC 61207-2:2019)
Ta slovenski standard je istoveten z: EN IEC 61207-2:2019
ICS:
71.040.20 Laboratorijska posoda in Laboratory ware and related
aparati apparatus
71.040.40 Kemijska analiza Chemical analysis
SIST EN IEC 61207-2:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN IEC 61207-2:2019
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SIST EN IEC 61207-2:2019
EUROPEAN STANDARD EN IEC 61207-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2019
ICS 71.040.40; 71.040.20 Supersedes EN 61207-2:1994 and all of its amendments
and corrigenda (if any)
English Version
Expression of performance of gas analyzers - Part 2: Measuring
oxygen in gas utilizing high-temperature electrochemical sensors
(IEC 61207-2:2019)
Expression des qualités de fonctionnement des analyseurs Angabe zum Betriebsverhalten von Gasanalysatoren - Teil
de gaz - Partie 2: Mesure de l'oxygène contenu dans le gaz 2: Sauerstoffmessung in Gas unter Verwendung von
en utilisant des capteurs électrochimiques à haute elektrochemischen Hochtemperatur-Sensoren
température (IEC 61207-2:2019)
(IEC 61207-2:2019)
This European Standard was approved by CENELEC on 2019-07-23. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61207-2:2019 E
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SIST EN IEC 61207-2:2019
EN IEC 61207-2:2019 (E)
European foreword
The text of document 65B/1156/FDIS, future edition 2 of IEC 61207-2, prepared by SC 65B
"Measurement and control devices" of IEC/TC 65 "Industrial-process measurement, control and
automation" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN IEC 61207-2:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-04-23
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-07-23
document have to be withdrawn
This document supersedes EN 61207-2:1994 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 61207-2:2019 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60654 (series) NOTE Harmonized as EN 60654 (series)
ISO 9001 NOTE Harmonized as EN ISO 9001
2
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EN IEC 61207-2:2019 (E)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61207-1 2010 Expression of performance of gas EN 61207-1 2010
analyzers - Part 1: General
3
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SIST EN IEC 61207-2:2019
IEC 61207-2
®
Edition 2.0 2019-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Expression of performance of gas analyzers –
Part 2: Measuring oxygen in gas utilizing high-temperature electrochemical
sensors
Expression des qualités de fonctionnement des analyseurs de gaz –
Partie 2: Mesure de l'oxygène contenu dans le gaz en utilisant des capteurs
électrochimiques à haute température
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 71.040.20; 71.040.40 ISBN 978-2-8322-7045-5
Warning! Make sure that you obtained this publication from an authorized distributor.
Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, and concepts . 6
3.1 Terms and definitions . 6
3.2 Concepts . 7
3.2.1 High-temperature electrochemical sensor . 7
3.2.2 Reference gas . 10
3.2.3 In situ analyzer . 10
3.2.4 Extractive analyzer . 11
3.2.5 Hazardous area . 11
3.2.6 Flame trap . 11
3.2.7 Essential ancillary units . 11
4 Procedures for specification . 11
4.1 General . 11
4.2 Specification of essential units and ancillary services . 11
4.2.1 General . 11
4.2.2 Rated range of reference gas pressure . 11
4.2.3 Rated range of calibration gas pressure. 12
4.2.4 Rated range of aspirator gas pressure . 12
4.3 Additional terms related to the specification of performance . 12
4.4 Important terms related to the specification of performance . 12
4.4.1 General . 12
4.4.2 Rated range of sample gas temperature . 12
4.4.3 Rated range of sample gas pressure . 12
4.4.4 Rated range of interfering components . 12
5 Procedures for compliance testing . 13
5.1 General . 13
5.2 Testing procedures . 14
5.3 Output fluctuation . 14
5.4 Delay time, rise time and fall time . 15
Bibliography . 21
Figure 1 – Flow through tube sensor . 15
Figure 2 – Test tube sensor . 16
Figure 3 – Disc sensor . 16
Figure 4 – Twin chamber design . 16
Figure 5 – Sealed reference design . 17
Figure 6 – Limiting current design . 17
Figure 7 – Fixed volume design . 18
Figure 8 – General test arrangement: In situ analyzer . 19
Figure 9 – General test arrangement: Extractive analyzer . 20
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPRESSION OF PERFORMANCE OF GAS ANALYZERS –
Part 2: Measuring oxygen in gas
utilizing high-temperature electrochemical sensors
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61207-2 has been prepared by sub-committee 65B: Measurement
and control devices of IEC technical committee 65: Industrial-process measurement, control
and automation.
This second edition cancels and replaces the first edition published in 1994. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition.
a) all the terms and definitions relating to the document have been updated where
appropriate;
b) the description of the principle of the galvanic cell has been expanded and clarified;
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c) new definitions and illustrations have been added for different measurement methods for
oxygen using solid electrolytes for galvanic cells;
d) new illustrations have been added for existing descriptions for ion pump cells;
e) a more detailed description of the effect of the presence of oxidizable gases has been
added;
f) all references to “errors” have been replaced by “uncertainties” and appropriate updated
definitions applied.
The text of this International Standard is based on the following documents:
FDIS Report on voting
65B/1156/FDIS 65B/1158/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 61207-1:2010.
A list of all parts in the IEC 61207 series under the general title Expression of performance of
gas analyzers, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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IEC 61207-2:2019 © IEC 2019 – 5 –
INTRODUCTION
This part of IEC 61207 includes the terminology, definitions, statements and tests that are
specific to oxygen analyzers, which utilise high-temperature electrochemical sensors.
Oxygen analyzers employing high-temperature electrochemical sensors operating at tem-
peratures usually in excess of 500 °C, have a wide range of applications for the measurement
of oxygen in gas samples. Such samples are typically the result of a combustion process or
oxygen impurity measurements.
Two main types of analyzer exist, the in situ analyzer, where the sensor is positioned within
the process duct work, and the "extractive" analyzer, where the sample is drawn from the duct
via a simple sample system and presented to the sensor.
An analyzer will typically comprise a sensor head, mounted on the process duct, and a control
unit remotely mounted, with interconnecting cable.
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EXPRESSION OF PERFORMANCE OF GAS ANALYZERS –
Part 2: Measuring oxygen in gas
utilizing high-temperature electrochemical sensors
1 Scope
This part of IEC 61207 applies to all aspects of analyzers using high-temperature electro-
chemical sensors for the measurement of oxygen in gas.
It applies to in-situ and extractive analyzers and to analyzers installed indoors and outdoors.
The object of this part is:
– to specify the terminology and definitions related to the functional performance of gas
analyzers, utilizing a high-temperature electrochemical sensor, for the continuous
measurement of oxygen concentration in a sample of gas;
– to unify methods used in making and verifying statements on the functional performance of
such analyzers;
– to specify what tests are performed to determine the functional performance and how such
tests are carried out;
– to provide basic documents to support the application of internationally recognized quality
management standards.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 61207-1:2010, Expression of performance of gas analyzers – Part 1: General
3 Terms, definitions, and concepts
3.1 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
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3.2 Concepts
3.2.1 High-temperature electrochemical sensor
3.2.1.1 General
°
The sensor is usually controlled at a stable, high temperature, typically in excess of 500 C.
This high temperature is normally maintained by an electric heater, however, in some high-
temperature in-situ applications, the sensor may require cooling to be applied. The sensor
may also be run in passive mode with temperature sensing, where the heating is provided by
the sample environment and the measured temperature is used in the calculation of the
oxygen concentration. The high-temperature electrochemical sensor can be constructed in
two basic forms:
a) galvanic concentration cell;
b) ion pump cell.
3.2.1.2 Galvanic concentration cell (gauge cell)
3.2.1.2.1 General
Most commercially available analyzers employ the galvanic concentration cell consisting of
two gas volumes or chambers, separated by an oxygen ion conducting solid electrolyte, and
provided with a porous electrode on each side. The two sides are filled with sample gas on
the one side and a fixed oxygen partial pressure reference gas on the other side. The
reference gas shall contain some oxygen. The reference gas is usually air, but could be
another constant oxygen partial pressure mixture or even a sealed reference where the
oxygen partial pressure is maintained by a metal/metal oxide mixture.
The electrodes are catalytic and the electrode/solid electrolyte interface at elevated
2-
temperature allows the formation of oxygen ions (O ) which can then diffuse across the solid
electrolyte interface. This interface remains an impenetrable barrier for the other gases
present and thus provides a selective means of determining the partial pressure of oxygen
present in the sample gas. The solid electrolyte is typically yttrium oxide (yttria)-stabilized
zirconium oxide (zirconia), and the porous electrode is platinum based, although other
materials may be used. The signal magnitude is temperature dependent and thus requires a
low uncertainty of temperature measurement of the solid electrolyte interface by employing
IEC 60751, and stability of heating provided
temperature sensors as given in IEC 60584 and
to achieve the high temperatures required for efficient and sensitive operation.
When the sensor is brought to a temperature at which the solid electrolyte conducts oxygen
ions, and the e.m.f. between the two electrodes is measured, the output will be related to the
logarithm of the ratio of the partial pressures of oxygen at each of the electrodes in
accordance with the Nernst formula:
RT P
1
E= ln
(1)
4FP
2
P
1
E= k log
10
(2)
P
2
P
1
ET()mV = 0,0496 log
10
(3)
P
2
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where
P is the partial pressure of oxygen in the reference gas;
1
P is the partial pressure of oxygen in the sample gas;
2
E is the electromotive force output from the cell in mV;
-1 -1
R is the gas constant (8,314 4 J K mol );
T is the absolute temperature (K);
4 -1
F is the Faraday constant (9,648 53 x 10 C mol );
k is the Nernstian coefficient (slope factor).
Thus, provided the oxygen partial pressure is known at one electrode (P ), then the potential
1
difference between the two electrodes will enable the unknown oxygen pressure to be
determined at the other electrode (P ).
2
Note that in the above formulae, it is the partial pressure of oxygen on the two sides which is
important, not the fractional component of the oxygen. Therefore, if equal component mixtures
containing oxygen (e.g. air), but at different absolute pressures, are applied to either side of
the solid electrolyte barrier, the signal will not be 0 mV, but proportional to the logarithm of the
ratio of the absolute pressures of the gases on each side.
The Nernstian response of the high-temperature electrochemical ceramic sensor holds over a
very wide range of oxygen partial pressures differences, and the sensor output increases
logarithmically with linear reduction of the oxygen's partial pressure at a given temperature.
The sensor output is directly proportional to temperature, and hence for quantitative analysis,
the temperature of the cell should be closely controlled and/or measured, and the necessary
corrections applied in Formula (1).
Theoretically, the output e.m.f. of the sensor, when the partial pressures of the sample gas
and reference gas are equal, is 0 V. However, in some sensors, a zero offset is measured and
is considered as being largely due to thermo-electric effects and thermal gradients across the
electrodes. This offset can be considered theoretically as an extra constant (asymmetry
potential).
P
1
Ek(mV) log+U
10 a
(4)
P
2
P
1
EU()mV 0,0496 log+
10 a
(5)
P
2
where
U is the asymmetry potential (mV).
a
Non-ideal oxygen ion conduction can also be compensated for by introducing modifications to
the slope factor k.
In practice, manufacturers whose sensors exhibit zero offset may supply practical average
values of U to help in calibration. Modern equipment can automatically compensate the
a
asymmetry potential during air point calibration (i.e. air in both chambers).
Typical applications are in combustion control, which measures the oxygen level which can be
in the order of a few percentage points under normal working conditions or in oxygen
contamination, for example in nitrogen production and purification using ASUs (air separation
units), where the oxygen level is in the region of a few parts per million. Therefore, it can be
seen that this technique provides a very wide potential measuring range of the oxygen level
from 100 % down to sub parts per million. In practice, the ultimate lower quantitative
=
=
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measurement limit depends on the leak integrity of the device and the limitations of the
electronics. The solid electrolyte sensors may have the gases actively flow fed or diffusionally
fed to the sample and reference sides of the solid electrolyte interface.
Some examples in 3.2.1.2.2 to 3.2.1.2.6 are given of generic sensor designs. For
simplification, the temperature sensors in these illustrations have been shown as being
positioned at the solid electrolyte interface, however, the practical implementation of a generic
design may limit the actual physical location of the temperature sensor. Any non-ideal location
may give rise to a voltage offset (U ) as illustrated in Formulae (4) and (5).
a
NOTE Platinum is frequently used for the electrodes, and the ceramic electrolyte is usually zirconium oxide, fully
or partially stabilized with yttrium oxide, calcium oxide or thorium oxide, which, when heated above 500 °C, allows
the charge transfer mechanism to be predominantly oxygen ion conduction.
3.2.1.2.2 Flow through tube sensor
The solid electrolyte tube is given porous electrodes on the inner and outer surfaces. The
tube is hermetically sealed to inlet and outlet pipes and sample gas flows through the inner
tube, whilst the reference gas (air) surrounds the outer surface. This is shown schematically
in Figure 1.
3.2.1.2.3 Test tube sensor
A solid electrolyte tube is sealed at one end and porous electrodes placed on the inner and
outer surfaces. The sample either flows past or diffuses around the outside of the tube. A
reference gas (air) is in the middle of the tube. External heating provides the high temperature
required. This is shown schematically in Figure 2.
3.2.1.2.4 Disc sensor
A solid electrolyte disc with porous electrodes on each face is sealed into a tube with matched
coefficient of thermal expansion. The outside surface is exposed to sample gas and the inside
surface to a reference gas (air). The high temperature is provided by an internal heater on the
reference side. This configuration is suitable for use as part of an in situ probe for oxygen
measurements. This is shown schematically in Figure 3.
3.2.1.2.5 Twin chamber design
In this design, the sample and reference gases are either flowed or diffusionally fed into two
chambers separated by a solid electrolyte interface. The high working temperature required is
provided by a band heater or equivalent around the outer surface of the solid electrolyte tube,
which gives a relatively wide area of flat thermal gradient leading to a highly stable reading.
This arrangement is best suited for an extractive or close coupled extractive arrangement.
This is shown schematically in Figure 4.
3.2.1.2.6 Sealed reference design
This has similarities to the above generic configurations, however, instead of using a
continuously replenished reference gas (air), a sealed reference volume is used. It is
important to retain a constant partial pressure of oxygen within this volume, and this is
normally achieved by using a mixture of metal and metal oxide powders which maintains an
equilibr
...
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