Ambient air - Standard method for the measurement of benzene concentrations - Part 3: Automated pumped sampling with in situ gas chromatography

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union Reference Method for the determination of benzene in ambient air [1] for the purpose of comparison of measurement results with limit values with a one-year reference period.
The standard describes guidelines for measurements with, and type approval of, automated gas chromatographs. The use of automated instruments gives this part a different structure compared to the other parts including the procedure for selecting an appropriate automated gas chromatograph by means of type approval tests.
Requirements for use in the field are also described.
The standard is applicable to measurements of airborne benzene vapour in the concentration range from 0 µg/m3 to 50 µg/m3 (Standardised to 101,3 kPa and 293 K). This concentration range represents the certification range for benzene in the type approval test.

Außenluft - Referenzverfahren zur Bestimmung von Benzolkonzentrationen - Teil 3: Automatische Probenahme mit einer Pumpe mit gaschromatographischer In-situ-Bestimmung

Diese Europäische Norm legt ein quasikontinuierliches Messverfahren zur Bestimmung der Konzentration von Benzol in Außenluft mit automatisierter Probenahme und gaschromatographischer Analyse fest. Diese Norm beschreibt die Leistungskenngrößen und legt die betreffenden Mindestkriterien für die Eignungsprüfung eines automatischen Gaschromatographen (GC) fest. Sie beinhaltet auch die Bewertung der Eignung eines Messgeräts für die Anwendung an einem ortsfesten Messstandort bezüglich der Anforderungen an die Datenqualität nach Anhang I der Richtlinie 2008/50/EG [1] und bezüglich der Anforderungen an Probenahme, Kalibrierung und Qualitätssicherung.
Das Verfahren ist anwendbar zur Bestimmung der Massenkonzentration von Benzol in Außenluft bis 50 µg/m3. Dieser Konzentrationsbereich entspricht dem Zertifizierungsbereich der Eignungsprüfung.
Abhängig von den in Außenluft vorliegenden Konzentrationen dürfen auch andere Bereiche gewählt werden.
ANMERKUNG 1   Wird die Norm für andere Zwecke als die von der Richtlinie 2008/50/EG geforderten Messungen angewendet, brauchen die Bereiche und Anforderungen an die Unsicherheit nicht zur Anwendung zu kommen.
Das Verfahren umfasst die Bestimmung der Konzentrationen von Benzol in Außenluft an Standorten, die als ländlich, städtischer Hintergrund, verkehrsbezogen und von industriellen Quellen beeinflusst eingestuft werden.
Die Ergebnisse werden in µg/m3 (bei 20 °C und 101,3 kPa) angegeben.
ANMERKUNG 2   50 µg/m3 Benzol entsprechen 15,4 nmol/mol Benzol.
Diese Norm enthält Informationen für verschiedene Anwendergruppen.
Die Abschnitte 5 bis 7 und die Anhänge C und D enthalten allgemeine Angaben zur Messung von Benzol mit automatischer Gaschromatographie und Probenahmeeinrichtung.
Abschnitt 8 und Anhang E richten sich an Prüfstellen und  laboratorien, die Eignungsprüfungen von Benzol-Messgeräten durchführen. Diese Abschnitte enthalten Angaben über:
-   Prüfbedingungen, -verfahren und -anforderungen der Eignungsprüfung;
-   Anforderungen an die Leistungsfähigkeit des Messgeräts;
-   die Bewertung der Ergebnisse der Eignungsprüfung;
-   die Bewertung der Unsicherheit der Messergebnisse des Benzol-Messgeräts auf der Grundlage der Ergebnisse der Eignungsprüfung.
Die Abschnitte 9 bis 11 und Anhang F richten sich an die Betreiber von Messnetzen, in denen Benzol-Messungen in Außenluft durchgeführt werden. Diese Abschnitte enthalten Angaben über:
-   die Erstinstallation des Messgeräts im Messnetz und die Beurteilung von dessen Eignung;
-   die laufende Qualitätssicherung;
-   die Berechnung der Ergebnisse und den Messbericht;
-   die Bewertung der Unsicherheit der Messergebnisse unter praktischen Messbedingungen.

Air ambiant - Méthode normalisée de mesurage de la concentration en benzene - Partie 3: Méthode à chromatographie en phase gazeuse automatique

La présente Norme européenne spécifie une méthode de mesure semi-continue pour la détermination de la concentration en benzène dans l’air ambiant par prélèvement automatique et analyse par chromatographie en phase gazeuse. La présente norme décrit les caractéristiques de performance et fixe les critères minimaux requis pour sélectionner un chromatographe en phase gazeuse automatisé approprié (GC) à l’aide d’essais d’approbation de type. Elle présente également l’évaluation de l’aptitude à l’emploi d’un analyseur sur un site déterminé spécifique de manière à répondre aux exigences de qualité des données spécifiées dans l’Annexe I de la Directive 2008/50/CE [1] 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 benzène présent dans l’air ambiant jusqu’à 50 µg/m3. Cette plage de concentration représente la gamme de certification pour l’essai d’approbation 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 benzène dans l’air ambiant dans les zones classées comme zones rurales, urbaines de fond, proches d’axes de circulation automobile et influencées par des sources industrielles.
Les résultats sont exprimés en µg/m3 (à 20 °C et 101,3 kPa).
NOTE 3   50 µg/m3 de benzène correspondent à 15,4 nmol/mol de benzène.
La présente norme contient des informations pour différents groupes d’utilisateurs.
Les Articles 5 à 7 et les Annexes C et D contiennent des informations générales relatives aux principes de mesure du benzène à l’aide d’un chromatographe en phase gazeuse automatisé 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 des essais d’approbation de type des analyseurs de benzène. Ces sections contiennent des informations concernant :
-   les conditions de l’essai d’approbation de type, les modes opératoires d’essai et les exigences d’essai ;
-   les exigences de performance de l’analyseur ;
-   l’évaluation des résultats de l’essai d’approbation de type ;
-   l’évaluation de l’incertitude des résultats de mesure de l’analyseur de benzène d’après les résultats de l’essai d’approbation de type.
Les Articles 9 à 11 et les Annexes F à H concernent les réseaux de surveillance effectuant les mesurages pratiques du benzène 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 de routine ;
-   le calcul et le compte-rendu des résultats de mesure ;
-   l’évaluation de l’incertitude des résultats de mesure sous des conditions de surveillance pratiques.

Zunanji zrak - Standardna metoda za določevanje koncentracije benzena - 3. del: Avtomatsko vzorčenje s črpanjem in določevanje s plinsko kromatografijo na kraju samem (in situ)

Ta del standarda EN 14662 je v skladu s splošno metodologijo, ki je bila izbrana kot podlaga za referenčno metodo Evropske unije za določevanje benzena v zunanjem zraku [1] za namen primerjave rezultatov meritev z mejnimi vrednostmi v enoletnem referenčnem obdobju.
Standard opisuje smernice za meritve z avtomatiziranimi plinskimi kromatografi in homologacijo le-teh. Zaradi uporabe avtomatiziranih instrumentov se struktura tega dela razlikuje od strukture drugih delov, vključno s postopkom izbire primernega avtomatiziranega plinskega kromatografa prek homologacijskih preizkusov.
Opisane so tudi zahteve za uporabo na terenu.
Standard velja za meritve hlapov benzena v zraku v koncentracijah od 0 µg/m3 do 50 µg/m3 (standardizirano na 101,3 kPa in 293 K). Te koncentracije predstavljajo razpon certificiranja za benzen za homologacijski preizkus.

General Information

Status
Published
Public Enquiry End Date
30-Sep-2013
Publication Date
21-Dec-2015
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
10-Dec-2015
Due Date
14-Feb-2016
Completion Date
22-Dec-2015

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Außenluft - Referenzverfahren zur Bestimmung von Benzolkonzentrationen - Teil 3: Automatische Probenahme mit einer Pumpe mit gaschromatographischer In-situ-BestimmungAir ambiant - Méthode normalisée de mesurage de la concentration en benzene - Partie 3: Méthode à chromatographie en phase gazeuse automatiqueAmbient air - Standard method for the measurement of benzene concentrations - Part 3: Automated pumped sampling with in situ gas chromatography13.040.20Kakovost okoljskega zrakaAmbient atmospheresICS:Ta slovenski standard je istoveten z:EN 14662-3:2015SIST EN 14662-3:2016en,fr,de01-februar-2016SIST EN 14662-3:2016SLOVENSKI

STANDARDSIST EN 14662-3:20051DGRPHãþD
SIST EN 14662-3:2016
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14662-3
November
t r s w ICS
s uä r v rä t r Supersedes EN
s v x x tæ uã t r r wEnglish Version

Ambient air æ Standard method for the measurement of benzene concentrations æ Part

uã Automated pumped sampling with in situ gas chromatography Qualité de l 5air ambiant æ Méthode normalisée pour le mesurage de la concentration en benzène æ Partie

uã Prélèvement par pompage automatique avec analyse chromatographique en phase gazeuse sur site

Außenluft æ Messverfahren zur Bestimmung von Benzolkonzentrationen æ Teil

uã Automatische Probenahme mit einer Pumpe und gaschromatographische InæsituæBestimmung This European Standard was approved by CEN on

s y July
t r s wä

egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä

translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä

CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey andUnited Kingdomä

EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels

t r s w CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN

s v x x tæ uã t r s w ESIST EN 14662-3:2016

EN 14662-3:2015 (E) 2 Contents Page European foreword ....................................................................................................................................................... 4 1 Scope .................................................................................................................................................................... 5 2 Normative references .................................................................................................................................... 6 3 Terms and definitions ................................................................................................................................... 6 4 Abbreviated terms ....................................................................................................................................... 11 5 Principle .......................................................................................................................................................... 12 5.1 General ............................................................................................................................................................. 12 5.2 Measuring principle .................................................................................................................................... 12 5.3 Type approval test ....................................................................................................................................... 13 5.4 Field operation and quality control....................................................................................................... 14 6 Sampling equipment ................................................................................................................................... 14 6.1 General ............................................................................................................................................................. 14 6.2 Sampling location ......................................................................................................................................... 14 6.3 Sampling system ........................................................................................................................................... 14 6.4 Control and regulation of sample volume ........................................................................................... 15 6.5 Sampling pump for the manifold ............................................................................................................ 15 7 Analyser equipment .................................................................................................................................... 16 7.1 General ............................................................................................................................................................. 16 7.2 Sampling trap ................................................................................................................................................ 16 7.3 Sampling device ............................................................................................................................................ 16 7.4 Thermal desorption unit ........................................................................................................................... 16 7.5 Separation unit.............................................................................................................................................. 16 7.6 Detector ........................................................................................................................................................... 16 7.7 Data processing system ............................................................................................................................. 17 8 Type approval of benzene analysers ..................................................................................................... 17 8.1 General ............................................................................................................................................................. 17 8.2 Relevant performance characteristics and performance criteria.............................................. 18 8.3 Design changes (EN 15267-1 and EN 15267-2) ................................................................................. 19 8.4 Procedures for determination of the performance characteristics during the laboratory test ............................................................................................................................................... 19 8.5 Determination of the performance characteristics during the field test................................. 27 8.6 Expanded uncertainty calculation for type approval ..................................................................... 31 9 Field operation and ongoing quality control ..................................................................................... 31 9.1 General ............................................................................................................................................................. 31 9.2 Suitability evaluation .................................................................................................................................. 32 9.3 Initial installation ........................................................................................................................................ 33 9.4 Ongoing quality assurance/quality control ........................................................................................ 34 9.5 Calibration of the analyser ....................................................................................................................... 36 9.6 Checks ............................................................................................................................................................... 37 9.7 Maintenance ................................................................................................................................................... 41 9.8 Data handling and data reports .............................................................................................................. 41 9.9 Measurement uncertainty ........................................................................................................................ 42 10 Expression of results ................................................................................................................................... 42 SIST EN 14662-3:2016

EN 14662-3:2015 (E) 3 11 Test reports and documentation ............................................................................................................ 42 11.1 Type approval test ........................................................................................................................................ 42 11.2 Field operation .............................................................................................................................................. 44 Annex A (normative)

Test of lack of fit .............................................................................................................. 45 Annex B (informative) Sampling equipment .................................................................................................... 47 Annex C (informative)

Components and applications of benzene analysers ....................................... 48 Annex D (informative)

Manifold testing equipment ..................................................................................... 50 Annex E (normative)

Type approval ................................................................................................................... 52 Annex F (informative)

Calculation of uncertainty in field operation at the annual limit value .................................................................................................................................................................. 65 Bibliography ................................................................................................................................................................. 72

SIST EN 14662-3:2016

EN 14662-3:2015 (E) 4 European foreword This document (EN 14662-3:2015) 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 May 2016, and conflicting national standards shall be withdrawn at the latest by May 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14662-3:2005. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association and supports Essential Requirements of the Council Directive 2008/50/EC [1]. Details of significant technical changes between this European Standard and the previous edition are:

— Clause 8 has been brought in line with other Standards dealing with type approval of gas analysers; — In 9.4 and 9.6, performance requirements have been modified or removed and additional performance criteria and tests have been introduced for repeatability at span level; — In 9.5, formulae have been introduced for software adjustment of the raw analyser signal after calibration; — In Annexes E and F, uncertainty calculations have been modified to be in conformity with EN ISO 14956. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 14662-3:2016

EN 14662-3:2015 (E) 5 1 Scope This European Standard specifies a semi-continuous measurement method for the determination of the concentration of benzene present in ambient air based on automated sampling and analysis by gas chromatography. This European Standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate automated gas chromatograph (GC) 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 benzene present in ambient air in the range up to 50 µg/m3 benzene. This concentration range represents the certification range for the type approval test. Other ranges may be used depending on the levels present in ambient air.

NOTE 1 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 benzene in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources. The results are expressed in µg/m3 (at 20 °C and 101,3 kPa). NOTE 2 50 µg/m3 of benzene corresponds to 15,4 nmol/mol of benzene. This European Standard contains information for different groups of users. Clauses 5 to 7 and Annexes C and D contain general information about the principles of benzene measurement by automated gas chromatography and sampling equipment. Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of benzene 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 benzene 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 benzene 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. SIST EN 14662-3:2016

EN 14662-3:2015 (E) 6 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. 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
Certification of automated measuring systems
Part 1: General principles EN 15267-2, Air quality
Certification of automated measuring systems

Part 2: Initial assessment of the AMS manufacturer’s quality management system and post certification surveillance for the manufacturing process EN ISO 6142, Gas analysis

Preparation of calibration gas mixtures
Gravimetric method (ISO 6142) 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 method (ISO 6144) EN ISO 6145-4, Gas analysis
Preparation of calibration gas mixtures using dynamic volumetric methods

Part 4: Continuous syringe injection method (ISO 6145-4) EN ISO 6145-6, Gas analysis

Preparation of calibration gas mixtures using dynamic volumetric methods
Part 6: Critical 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 6145-8, Gas analysis
Preparation of calibration gas mixtures using dynamic volumetric methods
Part 8: Diffusion method (ISO 6145-8) EN ISO 6145-9, Gas analysis
Preparation of calibration gas mixtures using dynamic volumetric methods
Part 9: Saturation method (ISO 6145-9) EN ISO 6145-10, Gas analysis
Preparation of calibration gas mixtures using dynamic volumetric methods
Part 10: Permeation method (ISO 6145-10) EN ISO 14956, Air quality

Evaluation of the suitability of a measurement procedure by comparison with a required measurement uncertainty (ISO 14956) ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 adjustment 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). SIST EN 14662-3:2016

EN 14662-3:2015 (E) 7 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 European Standard, adjustment is performed on measurement data rather than on the analyser. [SOURCE: JCGM 200:2012 (VIM), Note 3 to entry has been modified, [2]] 3.2 ambient air outdoor air in the troposphere, excluding workplaces as defined by Directive 89/654/EEC where provisions concerning health and safety at work apply and to which members of the public do not have regular access [SOURCE: 2008/50/EC [1]] 3.3 analyser analytical instrument that provides an output signal which is a function of the concentration, partial pressure, flow or temperature of one or more components of a gas mixture 3.4 availability of the analyser fraction of the total 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. [SOURCE: JCGM 200:2012 (VIM), modified, 3rd note has been deleted] 3.6 carry-over (memory effect) influence of the previous measurement due to the retention of benzene within the instrument 3.7 certification range concentration range for which the analyser is type approved 3.8 check verification that the analyser is still operating within specified performance limits SIST EN 14662-3:2016

EN 14662-3:2015 (E) 8 3.9 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 covariances of these other quantities weighted according to how the measurement result varies with changes in these quantities [SOURCE: ISO/IEC Guide 98-3:2008] 3.10 coverage factor numerical factor used as a multiplier of the combined standard uncertainty in order to obtain an expanded uncertainty [SOURCE: ISO/IEC Guide 98-3:2008] 3.11 competent body body which has been designated for a specific task (type approval tests and/or QA/QC activities in the field) by the competent authority in the Member States 3.12 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 3,3x(srz/B), where srz is the standard deviation of instrument response at zero measurand concentration and B is the slope of the calibration function [5]. Note 2 to entry:

In principle, the response of the instruments described in this standard to a zero concentration of benzene should be zero. Consequently, srz may be determined by repeatedly measuring a low concentration of benzene, e.g., 10 % of the level of the annual limit value (see 8.4.4). 3.13 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 characterized 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. [SOURCE: ISO/IEC Guide 98-3:2008] Note 3 to entry: For the purpose of this standard 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 %. 3.14 independent measurement individual measurement that is not influenced by a previous individual measurement SIST EN 14662-3:2016

EN 14662-3:2015 (E) 9 3.15 individual measurement measurement over a time period equal to the cycle time of the analyser Note 1 to entry: Cycle time is defined as the time taken for the analyser to complete all the required functions to report a single measurement. This may include some or all of the following: sample collection, sample trapping, sample desorbing, chromatographic analysis, analyser preparation for next measurement cycle. 3.16 influence quantity quantity that is not the measurand but that affects the result of the measurement

[SOURCE: ISO/IEC Guide 98-3:2008] 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 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: 2008/50/EC [1]] 3.20 long term drift difference between zero or span readings over a determined period of time (e.g. period of unattended operation) 3.21 monitoring station enclosure located in the field in which an analyser has been installed to monitor concentrations of one or more ambient air pollutants in such a way that its performance and operation complies with the prescribed requirements 3.22 parallel measurements measurements from

analysers of same type and model, sampling from one and the same sampling manifold starting at the same time and ending at the same time 3.23 performance characteristic one of the parameters assigned to equipment in order to define its performance SIST EN 14662-3:2016

EN 14662-3:2015 (E) 10 3.24 performance criterion limiting quantitative numerical value assigned to a performance characteristic, to which conformance is tested 3.25 period of unattended operation time period over which the drift complies with the performance criterion for long term drift 3.26 repeatability (of results of measurement) closeness of the agreement between the results of successive individual measurements of benzene carried out under the same conditions of measurement Note 1 to entry: These conditions include: — the same measurement procedure; — the same observer; — the same analyser, used under the same conditions; — at the same location; — repetition over a short period of time. 3.27 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: — the same measurement procedure; — two identical analysers, used under the same conditions; — at the same monitoring station; — the period of unattended operation. 3.28 sampled air ambient air that has been sampled through the sampling inlet and sampling system 3.29 sample gas temperature temperature of the sampled gas at the sample inlet outside the monitoring station 3.30 sampling device component of the analyser which samples an accurately known volume of ambient air Note 1 to entry: For the purpose of this European Standard, typical devices may consist of a mass-flow controller and timed switching valve, or a sampling syringe.

SIST EN 14662-3:2016

EN 14662-3:2015 (E) 11 3.31 sampling system assembly of components needed to transfer the sampled air to the analyser 3.32 short-term drift difference between zero or span readings at the beginning and end of a 12-hour period 3.33 standard uncertainty uncertainty of the result of a measurement expressed as a standard deviation

[SOURCE: ISO/IEC Guide 98-3:2008] 3.34 surrounding temperature temperature of the air directly surrounding the analyser (temperature inside the monitoring station or laboratory) 3.35 type approval decision taken by a competent body that the pattern of an analyser conforms to specified requirements

3.36 type approval test examination of two or more analysers of the same pattern which are submitted by a manufacturer to a competent body including the tests necessary for approval of the pattern 3.37 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: ISO/IEC Guide 98-3:2008] 4 Abbreviated terms

AMS automated measuring system MFC mass flow controller PTFE polytetrafluoroethylene QA quality assurance QC quality control SIST EN 14662-3:2016

EN 14662-3:2015 (E) 12 5 Principle 5.1 General This European Standard describes the method for measurement of the concentration of benzene in ambient air by means of automated sampling and analysis by gas chromatography (GC). The requirements, the specific components of the GC 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 so-called type approval test for which procedures have been described. The type approval test comprises a laboratory and a field test. The selection of a type approved analyser for a specific measuring task in the field is based on the calculation of the expanded uncertainty of the measurement method. In this expanded uncertainty calculation the actual values of various performance characteristics of a type approved analyser and the site-specific conditions at the monitoring station are taken into account (see 9.6). The expanded uncertainty of the method shall not exceed 25 % for fixed measurements or 30 % for indicative measurements, as specified in Annex I of Directive 2008/50/EC. Requirements and recommendations for quality assurance and quality control are given for the measurements in the field (see 9.4). 5.2 Measuring principle A measured volume of sample air is drawn or forced through a sampling trap (sorbent tube). Provided suitable sorbents are chosen, benzene is retained by the sorbent tube and is quantitatively removed from the flowing air stream. The collected benzene is desorbed by heat and is transferred by inert carrier gas into a gas chromatograph equipped with a capillary column and a suitable detector (see 7.6), where it is analysed. Prior to entering the column the sample may be concentrated either on a cryo-trap, which is heated to release the sample into the column, or on a pre-column, where higher boiling hydrocarbons are removed from the pre-column by back flush.

Two general types of instruments are used. One type
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