SIST EN 14626:2025
(Main)Ambient air - Standard method for the measurement of the concentration of carbon monoxide by non-dispersive infrared spectroscopy
Ambient air - Standard method for the measurement of the concentration of carbon monoxide by non-dispersive infrared spectroscopy
This European Standard specifies a continuous measurement method for the determination of the concentration of carbon monoxide present in ambient air based on the non-dispersive infrared spectroscopic measuring principle.
This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate non-dispersive infrared spectroscopic analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass concentration of carbon monoxide present in ambient air up to 100 mg/m3 carbon monoxide. This concentration range represents the certification range for the type approval test.
NOTE 1 Other ranges may be used depending on the levels present in ambient air.
NOTE 2 When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of carbon monoxide in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in mg/m3 (at 20 °C and 101,3 kPa).
NOTE 3 100 mg/m3 of CO corresponds to 86 μmol/mol of CO.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes B, C and D contain general information about the principles of carbon monoxide measurement by non-dispersive infrared spectroscopic analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of carbon monoxide analysers. These sections contain information about:
− type-approval test conditions, test procedures and test requirements;
− analyser performance requirements;
− evaluation of the type-approval test results;
− evaluation of the uncertainty of the measurement results of the carbon monoxide analyser based on the type approval test results.
Clauses 9 to 11 and Annex F are directed towards monitoring networks performing the practical measurements of carbon monoxide in ambient air. These sections contain information about:
− initial installation of the analyser in the monitoring network and acceptance testing;
− ongoing quality assurance/quality control;
− calculation and reporting of measurement results;
− evaluation of the uncertainty of measurement results under practical monitoring conditions.
Außenluft - Messverfahren zur Bestimmung der Konzentration von Kohlenmonoxid mit nicht-dispersiver Infrarot-Photometrie
Dieses Dokument legt ein kontinuierliches Messverfahren nach dem nicht-dispersiven Infrarot-Messprinzip zur Bestimmung der Konzentration von Kohlenmonoxid in Außenluft fest. Es nennt die Leistungskenngrößen und legt die Mindestanforderungen für die Eignungsprüfung von Infrarot-Photometern fest. Es beinhaltet auch die Bewertung der Eignung eines Messgeräts für den Einsatz an einem bestimmten ortsfesten Messstandort bezüglich der Anforderungen an die Datenqualität und bezüglich der Anforderungen für Probennahme, Kalibrierung und Qualitätssicherung.
ANMERKUNG 1 Zusätzliche Information ist in Anhang 1 der Richtline 2008/50/EG [1] gegeben
Das Verfahren ist anwendbar zur Bestimmung der Massenkonzentration von Kohlenmonoxid in Außenluft bis 100 mg/m3. Dieser Konzentrationsbereich entspricht dem Zertifizierungsbereich für die Eignungsprüfung.
ANMERKUNG 2 Je nach Konzentrationsniveau in der Luft können auch andere Bereiche gewählt werden.
ANMERKUNG 3 Wird diese Norm für andere Zwecke als für Messungen nach Richtlinie 2008/50/EG eingesetzt, dann brauchen die Anforderungen hinsichtlich Anwendungsbereich und Unsicherheit nicht zur Geltung kommen.
Das Verfahren umfasst die Bestimmung der Konzentration von Kohlenmonoxid an Standorten, die als ländlich, städtischer Hintergrund klassifiziert sind sowie für Probenahmepunkte, die durch Verkehr oder industrielle Quellen beeinflusst werden.
Die Ergebnisse werden in mg/m3 (bei 20 °C und 101,3 kPa) angegeben.
ANMERKUNG 4 100 mg/m3 Kohlenmonoxid entsprechen 86 μmol/mol Kohlenmonoxid.
Dieses Dokument enthält Informationen für verschiedene Nutzergruppen.
Abschnitt 5 bis Abschnitt 7 und Anhang B, Anhang C und Anhang D enthalten allgemeine Informationen über die Grundlagen der Kohlenmonoxid-Messung mit einem nicht-dispersiven Infrarot-Photometer sowie über die Probennahmeeinrichtung.
Abschnitt 8 und Anhang E richten sich speziell an Prüfinstitute und -laboratorien, die Eignungsprüfungen von Kohlenmonoxid-Messgeräten durchführen. Diese Abschnitte enthalten Informationen über
— Prüfbedingungen, -verfahren und -anforderungen bei der Eignungsprüfung;
— Anforderungen an die Leistungsfähigkeit des Messgeräts;
— die Bewertung der Ergebnisse der Eignungsprüfung;
— die Bewertung der Unsicherheit der Messergebnisse des Kohlenmonoxid-Messgeräts anhand der Eignungsprüfungsergebnisse.
Abschnitt 9 bis Abschnitt 11 und Anhang F richten sich an die Betreiber von Messnetzen, mit denen Kohlenmonoxid-Messungen in Außenluft durchgeführt werden. Diese Abschnitte enthalten Informationen über
— die Erstinstallation des Messgeräts im Messnetz und Eignungsbewertung;
— die laufende Qualitätssicherung und -kontrolle;
— die Berechnung und Übermittlung der Messergebnisse;
— die Bewertung der Unsicherheit der Messergebnisse unter Messbedingungen.
Das vorliegende Dokument stellt eine Weiterentwicklung der vorangegangenen Ausgaben (EN 14626:2005 und EN 14626:2012) dar. Bei der Beschaffung von Geräten, müssen diese vollständig mit dem vorliegenden Dokument übereinstimmen.
ANMERKUNG 5 Eignungsprüfungen, die vor der Veröffentlichung dieses Dokuments zum Zweck des Nachweises der Gleichwertigkeit durchgeführt wurden, sind weiterhin gültig.
ANMERKUNG 6 Eignungsprüfungen von Messgeräten, die vor der Veröffentlichung dieses Dokuments durchgeführt wurden, bleiben weiterhin für die Verwendung für regulierte Beobachtungszwecke gültig.
Air ambiant - Méthode normalisée de mesurage de la concentration en monoxyde de carbone par spectroscopie à rayonnement infrarouge non dispersif
Le présent document spécifie une méthode de mesurage en continu pour la détermination de la concentration en monoxyde de carbone dans l'air ambiant, selon le principe de mesure par spectroscopie à rayonnement infrarouge non dispersif. Le présent document décrit les caractéristiques de performance et fixe les critères minimaux requis pour sélectionner un analyseur par spectroscopie à rayonnement infrarouge non dispersif à l'aide de l’essai de type. Il présente également l'évaluation de l'aptitude à l'emploi d'un analyseur sur un site fixe spécifique afin de répondre aux exigences de qualité des données (voir l'Annexe I de la Directive 2008/50/CE [1] pour des informations supplémentaires) ainsi qu'aux exigences à observer au cours du prélèvement, de l'étalonnage et de l'assurance qualité.
La méthode s'applique à la détermination de la concentration massique en monoxyde de carbone présent dans l'air ambiant jusqu'à 100 mg/m3. Cette plage de concentration représente l'étendue de mesure certifiée pour l’essai de type.
NOTE 1 D'autres plages peuvent être utilisées selon les niveaux présents dans l'air ambiant.
NOTE 2 Lorsque la norme est utilisée à d'autres fins que la Directive 2008/50/CE, les exigences relatives à la plage et à l'incertitude peuvent ne pas s'appliquer.
La méthode couvre la détermination des concentrations en monoxyde de carbone présent dans l'air ambiant dans les lieux classés comme zones rurales et zones urbaines de fond, ainsi que pour les points de prélèvement influencés par la circulation automobile ou des sources industrielles.
Les résultats sont exprimés en mg/m3 (à 20 °C et 101,3 kPa).
NOTE 3 100 mg/m3 de CO correspondent à 86 µmol/mol de CO.
Le présent document contient des informations pour différents groupes d'utilisateurs.
Les Articles 5 à 7 et les Annexes B, C et D contiennent des informations générales relatives aux principes de mesurage du monoxyde de carbone à l'aide d'un analyseur par spectroscopie à rayonnement infrarouge non dispersif et d'un équipement de prélèvement.
L'Article 8 et l'Annexe E concernent tout particulièrement les entreprises et les laboratoires d'essai qui effectuent l’essai de type des analyseurs de monoxyde de carbone. Ces sections contiennent des informations concernant :
- les conditions de l’essai de type, les procédures de test et les exigences d'essai ;
- les exigences de performance de l'analyseur ;
- l'évaluation des résultats de l’essai de type ;
- l'évaluation de l'incertitude associée au mesurage effectué par l'analyseur de monoxyde de carbone d'après les résultats de l’essai de type.
Les Articles 9 à 11 et l'Annexe F concernent les réseaux de surveillance effectuant les mesurages concrets du monoxyde de carbone dans l'air ambiant. Ces sections contiennent des informations concernant :
- l'installation initiale de l'analyseur dans le réseau de surveillance et l'essai de réception ;
- l'assurance qualité/le contrôle qualité en continu ;
- le calcul et le compte-rendu des résultats de mesurage ;
- l'évaluation de l'incertitude des résultats de mesure sous des conditions de surveillance réelles.
Le présent document représente une évolution par rapport aux éditions antérieures (EN 14626:2005 et EN 14626: 2012).
NOTE 4 Les analyseurs soumis à essai de type avant la publication du présent document peuvent toujours être utilisés à des fins de surveillance réglementaire. Au fur et à mesure que de nouvelles versions des analyseurs testés dans le cadre du présent document sont disponibles, cesser d'utiliser les anciens analyseurs de référence.
Zunanji zrak - Standardna metoda za določanje koncentracije ogljikovega monoksida z nedisperzivno infrardečo spektroskopijo
Ta dokument določa metodo stalnega merjenja za določitev koncentracije ogljikovega monoksida v zunanjem zraku na podlagi nedisperznega infrardečega spektroskopskega merilnega principa. Ta dokument opisuje lastnosti delovanja in vzpostavlja ustrezna minimalna merila, potrebna za izbiro ustreznega nedisperznega infrardečega spektroskopskega analizatorja s tipskimi preskusi. Vključuje tudi oceno ustreznosti analizatorja za uporabo na specifičnem fiksnem mestu, da se izpolnijo zahteve o kakovosti podatkov (za več informacij glej dodatek I Direktive 2008/50/ES [1]) ter zahteve med vzorčenjem, kalibriranjem in zagotavljanjem kakovosti za uporabo.
Metoda se uporablja za določitev masne koncentracije ogljikovega monoksida v zunanjem zraku do vrednosti 100 mg/m3 ogljikovega monoksida. Te koncentracije predstavljajo razpon certificiranja za tipske preskuse.
OPOMBA 1: Uporabiti je mogoče tudi druge koncentracije, odvisno od ravni v zunanjem zraku.
OPOMBA 2: Če se standard uporablja za druge namene, ne za meritve v skladu z Direktivo 2008/50/ES, zahteve glede razponov in negotovosti morda ne veljajo.
Ta metoda zajema določitev koncentracij ogljikovega monoksida v zunanjem zraku na lokacijah, ki so uvrščene med podeželska območja in območja v urbanem okolju, ter za odvzemna mesta, na katera vpliva promet ali industrijski viri.
Rezultati so izraženi v mg/m3 (pri 20 °C in 101,3 kPa).
OPOMBA 3: 100 mg/m3 ogljikovega monoksida (CO) ustreza 86 μmol/mol ogljikovega monoksida.
Ta dokument vsebuje informacije za različne skupine uporabnikov.
Točke od 5 do 7 ter dodatki B, C in D vsebujejo splošne informacije o načelih merjenja ogljikovega monoksida z nedisperznim infrardečim spektroskopskim analizatorjem in opremo za vzorčenje.
Osrednji predmet obravnave v točki 8 in dodatku E so laboratoriji, ki izvajajo tipske preskuse analizatorjev ogljikovega monoksida. Ti razdelki vsebujejo informacije o:
pogojih tipskih preskusov ter preskusnih postopkih in zahtevah;
zahtevah glede učinkovitosti analizatorja;
ocenah rezultatov tipskih preskusov;
oceni povezane negotovosti meritev analizatorja ogljikovega monoksida na podlagi rezultatov tipskih preskusov.
Osrednji predmet obravnave v točkah od 9 do 11 ter dodatku F so mreže za spremljanje, ki izvajajo praktične meritve ogljikovega monoksida v zunanjem zraku. Ti razdelki vsebujejo informacije o:
začetni namestitvi analizatorja v mreži za spremljanje in preskušanju sprejemljivosti;
stalnem zagotavljanju oziroma nadzoru kakovosti;
izračunavanju in sporočanju rezultatov merjenja;
oceni negotovosti rezultatov merjenja v okviru pogojev praktičnega spremljanja.
Ta dokument je nadgradnja prejšnjih različic (EN 14626:2005 in EN 14626: (2012).
OPOMBA 4: Analizatorje, ki so bili tipsko preskušeni pred objavo tega dokumenta, je mogoče še vedno uporabljati za regulirano spremljanje. S pojavom novejših različic analizatorjev, preskušenih v skladu s tem dokumentom, se uporaba starejših referenčnih analizatorjev preneha.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2025
Nadomešča:
SIST EN 14626:2012
Zunanji zrak - Standardna metoda za določanje koncentracije ogljikovega
monoksida z nedisperzivno infrardečo spektroskopijo
Ambient air - Standard method for the measurement of the concentration of carbon
monoxide by non-dispersive infrared spectroscopy
Außenluft - Messverfahren zur Bestimmung der Konzentration von Kohlenmonoxid mit
nicht-dispersiver Infrarot-Photometrie
Air ambiant - Méthode normalisée de mesurage de la concentration en monoxyde de
carbone par spectroscopie à rayonnement infrarouge non dispersif
Ta slovenski standard je istoveten z: EN 14626:2024
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 14626
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2024
EUROPÄISCHE NORM
ICS 13.040.20 Supersedes EN 14626:2012
English Version
Ambient air - Standard method for the measurement of the
concentration of carbon monoxide by non-dispersive
infrared spectroscopy
Air ambiant - Méthode normalisée de mesurage de la Außenluft - Messverfahren zur Bestimmung der
concentration en monoxyde de carbone par Konzentration von Kohlenmonoxid mit nicht-
spectroscopie à rayonnement infrarouge non dispersif dispersiver Infrarot-Photometrie
This European Standard was approved by CEN on 11 November 2024.
CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14626:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 8
4 Abbreviated terms . 13
5 Principle . 13
5.1 General . 13
5.2 Measuring principle . 13
5.3 Type testing . 14
5.4 Field operation and quality control. 14
6 Sampling . 15
6.1 General . 15
6.2 Sampling location . 15
6.3 Sampling system . 15
6.3.1 Construction . 15
6.3.2 Particle filter . 16
6.3.3 Loss of carbon monoxide . 16
6.3.4 Conditioning . 16
6.4 Control and regulation of sample flow rate . 16
6.5 Sampling pump for the manifold . 17
7 Analyser equipment . 17
7.1 General . 17
7.2 Details about analyser equipment . 17
7.3 Pressure measurement . 17
7.4 Flow rate indicator . 17
7.5 Sampling pump for the analyser . 18
7.6 Particle filter . 18
8 Type testing of carbon monoxide analysers . 18
8.1 General . 18
8.2 Relevant performance characteristics and performance criteria. 19
8.3 Design change . 23
8.4 Procedures for determination of the performance characteristics during
the laboratory test . 23
8.4.1 General . 23
8.4.2 Test conditions . 23
8.4.3 Response time . 26
8.4.4 Short-term drift . 28
8.4.5 Repeatability standard deviation. 28
8.4.6 Lack of fit of linearity of the calibration function . 29
8.4.7 Sensitivity coefficient to sample gas pressure . 30
8.4.8 Sensitivity coefficient to the sample gas temperature . 31
8.4.9 Sensitivity coefficient to the surrounding temperature . 31
8.4.10 Sensitivity coefficient to electrical voltage . 32
8.4.11 Interferents . 33
8.4.12 Averaging test . 34
8.4.13 Difference sample/calibration port . 35
8.5 Determination of the performance characteristics during the field test . 36
8.5.1 General . 36
8.5.2 Selection of a monitoring station for the field test . 36
8.5.3 Operational requirements . 37
8.5.4 Long-term drift . 38
8.5.5 Reproducibility standard deviation under field conditions . 39
8.5.6 Period of unattended operation . 39
8.5.7 Period of availability of the analyser . 39
8.6 Expanded uncertainty calculation for type testing . 40
9 Field operation and ongoing quality control . 41
9.1 General . 41
9.2 Suitability evaluation . 41
9.2.1 General . 41
9.2.2 Analyser for a monitoring station or task. 41
9.3 Initial installation . 43
9.4 Ongoing quality assurance/quality control . 43
9.4.1 General . 43
9.4.2 Frequency of calibrations, checks and maintenance . 44
9.5 Calibration of the analyser . 47
9.5.1 General . 47
9.5.2 Calibration gases . 48
9.5.3 Data adjustment function . 48
9.5.4 Testing the sampling system . 48
9.5.5 Treatment of data after exceedance of performance criteria . 50
9.6 Checks . 52
9.6.1 Zero and span checks . 52
9.6.2 Lack-of-fit. 53
9.6.3 Testing the sampling system . 54
9.7 Maintenance . 56
9.7.1 Change of particle filters . 56
9.7.2 Maintenance of sampling system . 56
9.7.3 Change of consumables as applicable . 56
9.7.4 Preventive/routine maintenance of components of the analyser . 56
9.8 Data handling and data reports . 56
9.9 Measurement uncertainty . 57
10 Expression of results . 57
11 Test reports and documentation . 58
11.1 Type testing . 58
11.2 Field operation . 59
11.2.1 Suitability evaluation . 59
11.2.2 Documentation . 59
11.2.3 Ambient air quality data reports . 60
Annex A (normative) Test of lack-of-fit . 61
A.1 Establishment of the regression line . 61
A.2 Calculation of the residuals of the averages . 61
Annex B (informative) Sampling equipment . 63
Annex C (informative) Schematics of non-dispersive infrared spectrometer . 65
Annex D (informative) Manifold testing . 67
D.1 Procedure for applying test gas . 67
D.2 Procedure for the cross test . 68
D.2.1 General . 68
D.2.2 Initial stage . 68
D.2.3 Stage 1 . 69
D.2.4 Stage 2 . 69
D.2.5 Data Processing . 69
D.2.6 Evaluation . 69
Annex E (normative) Type testing. 71
E.1 Type testing and uncertainty calculation . 71
E.1.1 Type testing . 71
E.1.2 Uncertainty calculation . 71
E.2 Type testing Requirement a) . 71
E.3 Type testing Requirement b) . 73
E.3.1 General . 73
E.3.2 Calculation of standard uncertainties . 76
E.3.3 Example calculation . 83
E.4 Type testing Requirement c) . 85
E.5 Type testing Requirement d) . 85
E.5.1 General . 85
E.5.2 Combined standard uncertainty . 87
E.5.3 Absolute expanded uncertainty . 87
E.5.4 Relative expanded uncertainty . 88
E.5.5 Calculation of standard uncertainties . 88
E.5.6 Example calculation . 90
Annex F (informative) Calculation of uncertainty in field operation at the 8-hour limit value . 92
F.1 General . 92
F.2 Combined standard uncertainty . 92
F.3 Standard uncertainties . 93
F.3.1 General . 93
F.3.2 Influence quantities . 94
F.3.3 Interferents . 97
F.3.4 Averaging effect . 98
F.3.5 Reproducibility under field conditions . 98
F.3.6 Long-term drift at zero . 98
F.3.7 Long-term drift at level of the 8-hour limit value . 98
F.3.8 Zero gas . 99
F.3.9 Calibration gas . 99
F.3.10 Difference sample/calibration port . 99
F.4 Example calculation . 100
Annex G (informative) Test stand for the test point "sensitivity coefficient of sample gas
pressure" . 102
Annex H (informative) Significant changes . 104
Bibliography . 105
European foreword
This document (EN 14626:2024) has been prepared by Technical Committee CEN/TC 264 “Air quality,
the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2025, and conflicting national standards shall be
withdrawn at the latest by June 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document will supersede EN 14626:2012.
In comparison with the previous edition, the technical modifications made are listed in Annex H of this
document.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
1 Scope
This document specifies a continuous measurement method for the determination of the concentration
of carbon monoxide present in ambient air based on the non-dispersive infrared spectroscopic measuring
principle. This document describes the performance characteristics and sets the relevant minimum
criteria required to select an appropriate non-dispersive infrared spectroscopic analyser by means
of type testing. It also includes the evaluation of the suitability of an analyser for use in a specific fixed
site in order to meet data quality requirements (see Annex I of Directive 2008/50/EC [1] for additional
information) and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass concentration of carbon monoxide present in
ambient air up to 100 mg/m of carbon monoxide. This concentration range represents the certification
range for type testing.
NOTE 1 Other ranges can be used depending on the levels present in ambient air.
NOTE 2 When the standard is used for other purposes than for measurements required by Directive
2008/50/EC, the ranges and uncertainty requirements might not apply.
The method covers the determination of ambient air concentrations of carbon monoxide in locations
classified as rural areas, urban-background areas, and for sampling points influenced by traffic
or industrial sources.
The results are expressed in mg/m (at 20 °C and 101,3 kPa).
NOTE 3 100 mg/m of CO corresponds to 86 µmol/mol of CO.
This document contains information for different groups of users.
Clause 5 to Clause 7 and Annex B, Annex C and Annex D contain general information about the principles
of carbon monoxide measurement by non-dispersive infrared spectroscopic analyser and sampling
equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type
testing of carbon monoxide analysers. These sections contain information about:
type testing conditions, test procedures and test requirements;
analyser performance requirements;
evaluation of the type testing results;
evaluation of the associated uncertainty of the measurement performed by the carbon monoxide
analyser based on the type testing results.
Clause 9 to Clause 11 and Annex F are directed towards monitoring networks performing the practical
measurements of carbon monoxide in ambient air. These sections contain information about:
initial installation of the analyser in the monitoring network and acceptance testing;
ongoing quality assurance/quality control;
calculation and reporting of measurement results;
evaluation of the uncertainty to the measurement results under practical monitoring conditions.
This document represents an evolution of earlier editions (EN 14626:2005 and EN 14626: 2012).
NOTE 4 Analysers type tested prior to the publication of this document can still be used for regulated monitoring
purposes. As newer versions of analysers tested under this document become available, discontinue the use of older
reference analysers.
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.
EN 15267-1, Air quality - Assessment of air quality monitoring equipment - Part 1: General principles of
certification
EN 15267-2, Air quality - Assessment of air quality monitoring equipment - Part 2: Initial assessment of the
manufacturer’s quality management system and post certification surveillance for the manufacturing
process
EN ISO 6142-1, Gas analysis — Preparation of calibration gas mixtures — Gravimetric method (ISO 6142-
1)
EN ISO 6143, Gas analysis — Comparison methods for determining and checking the composition
of calibration gas mixtures (ISO 6143)
EN ISO 6144, Gas analysis — Preparation of calibration gas mixtures — Static volumetric methods
(ISO 6144)
EN ISO 6145-6, Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods
— Part 6: Critical flow orifices (ISO 6145-6)
EN ISO 6145-7, Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods
— Part 7: Thermal mass-flow controllers (ISO 6145-7)
EN ISO 14956, Air quality — Evaluation of the suitability of a measurement procedure by comparison with
a required measurement uncertainty (ISO 14956)
ISO 19229:2019, Gas analysis — Purity analysis and the treatment of purity data
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
adjustment of a measuring system
set of operations carried out on a measuring system so that it provides prescribed indications
corresponding to given values of a quantity to be measured
Note 1 to entry: Types of adjustment of a measuring system include zero adjustment of a measuring system, offset
adjustment, and span adjustment (sometimes called gain adjustment).
Note 2 to entry: Adjustment of a measuring system should not be confused with calibration, which is a prerequisite
for adjustment.
Note 3 to entry: In the context of this document, adjustment is performed on measurement data rather than on the
analyser.
[SOURCE: JCGM 200, 3.11 [2]]
3.2
ambient air
outdoor air in the troposphere where provisions concerning health and safety at work apply and to which
members of the public do not have regular access
Note 1 to entry: This excludes workplaces as defined by Directive 89/654/EEC.
[SOURCE: Council Directive 2008/50/EC [1]]
3.3
analyser
measuring system that provides an output signal which is a function of the concentration or
partial pressure of one or more components in a gas mixture and flow or temperature of this gas mixture
3.4
availability of the analyser
fraction of the time period for which valid measuring data of the ambient air concentration is available
from an analyser
3.5
calibration
operation that, under specified conditions, in a first step, establishes a relation between the quantity
values with measurement uncertainties provided by measurement standards and corresponding
indications with associated measurement uncertainties and, in a second step, uses this information
to establish a relation for obtaining a measurement result from an indication
Note 1 to entry: A calibration may be expressed by a statement, calibration function, calibration diagram, calibration
curve, or calibration table. In some cases, it may consist of an additive or multiplicative correction of the indication
with associated measurement uncertainty.
Note 2 to entry: Calibration should not be confused with adjustment of a measuring system, often mistakenly called
“self-calibration”, nor with verification of a calibration.
Note 3 to entry: Often, the first step alone in the above definition is perceived as being calibration.
Note 4 to entry: In the context of this document, calibration is a comparison of the analyser response to a known
gas concentration with a known uncertainty when the information obtained from the comparison is used
for the successive adjustment (if needed) of the analyser.
[SOURCE: JCGM 200, 2.39 [2]]
3.6
certification range
concentration range for which the analyser is type tested
3.7
check
verification that the analyser is still operating within specified performance limits
3.8
combined standard uncertainty
standard uncertainty of the result of a measurement when that result is obtained from the values
of a number of other quantities, equal to the positive square root of a sum of terms, the terms being
the variances or co-variances of these other quantities weighted according to how the measurement
result varies with changes in these quantities
[SOURCE: JCGM 100: 2.3.4 [3]]
3.9
coverage factor
numerical factor used as a multiplier of the combined standard uncertainty in order to obtain
an expanded uncertainty
[SOURCE: JCGM 100: 2.3.6 [3]]
3.10
competent body
organization which can demonstrate its competence for a specific task to the national competent
authority of the Member State
3.11
detection limit
smallest concentration of a measurand that can be reliably detected by a specific measurement process
Note 1 to entry: The detection limit is calculated as 3,3 x (sr,z/B) where sr,z is the standard deviation of analyser
response at zero measurand concentration (see 8.4.5) and B is the slope of the calibration function [4].
3.12
expanded uncertainty
quantity defining an interval about the result of a measurement that may be expected to encompass
a large fraction of the distribution of values that could reasonably be attributed to the measurand
Note 1 to entry: The fraction may be viewed as the coverage probability or level of confidence of the interval.
Note 2 to entry: To associate a specific level of confidence with the interval defined by the expanded uncertainty
requires explicit or implicit assumptions regarding the probability distribution characterised by the measurement
result and its combined standard uncertainty. The level of confidence that may be attributed to this interval can be
known only to the extent to which such assumptions may be justified.
Note 3 to entry: For the purpose of this document, the expanded uncertainty is the combined standard uncertainty
multiplied by a coverage factor k=2 resulting in an interval with a level of confidence of 95 %.
[SOURCE: JCGM 100: 2.3.5 [3]]
3.13
fall time
difference between the response time (fall) and the lag time (fall)
3.14
independent measurement
individual measurement that is not influenced by a previous individual measurement by separating
two individual measurements by at least four response times
Note 1 to entry: The largest value of response time (rise) and response time (fall) are intended.
3.15
individual measurement
measurement averaged over a time period equal to the response time of the analyser
Note 1 to entry: The largest value of response time (rise) and response time (fall) are intended.
Note 2 to entry: This definition differs from the meaning of the concept “individual measurement” in Directive
2008/50/EC [1].
3.16
influence quantity
quantity that is not the measurand but that affects the result of the measurement
[SOURCE: JCGM 100, B.2.10 [3]]
3.17
interferent
component of the air sample, excluding the measured constituent, that affects the output signal
3.18
lack of fit
maximum deviation from the linear regression line of the average of a series of measurement results
at the same concentration
3.19
lag time
time interval from the moment at which a step change of sample concentration occurs at the inlet of the
analyser to the moment at which the output reading reaches a level corresponding to a predefined change
of the stable output reading
3.20
limit value
level fixed on the basis of scientific knowledge, with the aim of avoiding, preventing or reducing harmful
effects on human health and/or the environment as a whole, to be attained within a given period
and not to be exceeded once attained
[SOURCE: Council Directive 2008/50/EC [1]]
3.21
long-term drift
difference between zero or span readings over a determined period of time (e.g. period of unattended
operation)
3.22
monitoring station
enclosure located in the field in which an analyser has been installed to monitor concentrations of one
or more ambient air pollutants
3.23
parallel measurements
measurements from different analysers sampling with the same sampling system, starting at the same
time and ending at the same time
Note 1 to entry: sampling can be performed from one and the same sampling manifold or with identical individual
sampling lines
3.24
performance characteristic
one of the parameters assigned to equipment in order to define its performance
3.25
performance criterion
limiting quantitative numerical value assigned to a performance characteristic, to which conformance
is tested
3.26
period of unattended operation
time period over which the drift complies with the performance criterion for long-term drift
3.27
repeatability of results of measurement
closeness of the agreement between the results of successive individual measurements of carbon
monoxide carried out under the same conditions of measurement
Note 1 to entry: These conditions include:
a) the same measurement procedure;
b) the same observer;
c) the same analyser, used under the same conditions;
d) at the same location;
e) repetition over a short period of time.
3.28
reproducibility under field conditions
closeness of the agreement between the results of simultaneous measurements with two analysers
in ambient air carried out under the same conditions of measurement
Note 1 to entry: These conditions are called field reproducibility conditions and include:
a) the same measurement procedure;
b) two identical analysers, used under the same conditions;
c) at the same monitoring station;
d) the period of unattended operation.
3.29
residence time in the sampling system
time period for the sampled air to be transferred to the inlet of the analyser
3.30
response time
time interval from the instant at which a step change of sample concentration occurs at the inlet of the
analyser to the instant at which the output reading reaches a level corresponding to 90 % of the stable
output reading
3.31
sampled air
part of ambient air that is transferred through the sampling inlet and sampling system for subsequent
measurement
3.32
sample gas temperature
temperature of the sampled gas at the sample inlet
Note 1 to entry: The term ‘gas’ may refer to a test gas used in type testing or to ambient air transferred
to the analyser.
3.33
sampling system
the assembly of components needed to transfer ambient air to the analyser
3.34
short-term drift
difference between zero or span readings at the beginning and end of a 12 h period
3.35
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation
[SOURCE: JCGM 100, 2.3.1] [3]]
3.36
surrounding temperature
temperature of the air directly surrounding the analyser
3.37
type testing
examination of two or more analysers of the same design which are submitted by a manufacturer to a
competent body including the tests necessary for approval of the design (determination of fitness
for purpose of a specific device model / of an unambiguous designated analyser)
Note 1 to entry: In EN 15267-1 and -2, type testing is referred to as performance testing.
3.38
uncertainty of measurement
parameter associated with the result of a measurement, that characterises the dispersion of the values
that could reasonably be attributed to the measurand
[SOURCE: JCGM 100, 2.2.3 [3]]
4 Abbreviated terms
AMS automated measuring system (sometimes referred to as continuous automated measurement
system (CAMS))
PFA perfluoro-alkoxy
PTFE polytetrafluoroethylene
5 Principle
5.1 General
This document describes the method for measurement of the concentrations of carbon monoxide
in ambient air by means of non-dispersive infrared spectrometry. The requirements, the specific
components of the infrared analyser and its sampling system are described. A number of performance
characteristics with associated minimum performance criteria are given for the analyser. The actual
values of these performance characteristics for a specific type of analyser shall be determined in a type
testing for which procedures have been described. The type testing comprises laboratory tests and field
tests. The selection of a type-tested analyser for a specific measuring task in the field is based on the
calculation of the expanded uncertainty of the measured values obtained by the measurement method.
In this expanded uncertainty calculation, the actual values of various performance characteristics of a
type-tested analyser and the site-specific conditions at the monitoring station are taken into account (see
Table 7 & 9.9). The expanded uncertainty of the method shall not exceed the limits (this is also specified
in Annex I of Directive 2008/50/EC [1]). Requirements and recommendations for quality assurance and
quality control are given for the measurements in the field (see 9.4).
5.2 Measuring principle
The attenuation of infrared light passing through a sample cell is a measure of the concentration of CO
in the cell. Not only CO but also most hetero-atomic molecules will absorb infrared light; in particular
water and CO have broad bands that can interfere with the measurement of CO. Different technical
solutions have been developed to suppress cross-sensitivity, instability and drift in order to design
continuous monitoring systems with acceptable properties. For instance:
measuring IR absorption of a specific wavelength (4,7 µm for CO);
dual-cell monitors, using a reference cell filled with clean air (compensation for drift), or single-cell
monitors alternating between sample and reference;
gas-filter correlation, "measuring" over a range of wavelengths.
Special attention shall be paid to infrared radiation absorbing gases that specifically absorb in the region
of detection of carbon monoxide.
The concentration of carbon monoxide is expressed in the units provided by the calibration standard.
The final results for reporting are express
...
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