SIST EN 14212:2012
(Main)Ambient air - Standard method for the measurement of the concentration of sulphur dioxide by ultraviolet fluorescence
Ambient air - Standard method for the measurement of the concentration of sulphur dioxide by ultraviolet fluorescence
This European Standard specifies a continuous measurement method for the determination of the concentration of sulphur dioxide present in ambient air based on the ultraviolet fluorescence measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet fluorescence 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 and requirements during sampling, calibration and quality assurance for use. The method is applicable to the determination of the mass concentration of sulphur dioxide present in ambient air up to 1000 μg/m3. This concentration range represents the certification range for SO2 for the type approval test. The method covers the determination of ambient air concentrations of sulphur dioxide 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). This standard contains information for different groups of users. Clauses 5 to 7 and Annexes C and D contain general information about the principles of sulphur dioxide measurement by ultraviolet fluorescence analyser and sampling equipment. Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of sulphur dioxide 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 sulphur dioxide analyser based on the typeapproval test results. Clauses 9 to 11 and Annexes F and G are directed towards monitoring networks performing the practical measurements of sulphur dioxide 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 Schwefeldioxid mit Ultraviolett-Fluoreszenz
Diese Europäische Norm legt ein kontinuierliches Ultraviolett-Fluoreszenz-Messverfahren zur Bestimmung der Konzentration von Schwefeldioxid in Luft fest. Es nennt die Leistungs¬kenngrößen und legt die Mindest-anforderungen für die Eignungsprüfung von Ultraviolett-Fluoreszenz-Messgeräten fest. Es beinhaltet auch die Bewertung der Eignung eines Messgeräts für den Einsatz an einem bestimmten ortsfesten Messstandort bezüglich der Anforderungen an die Datenqualität nach Anhang I der Richtlinie 2008/50/EG [1] und bezüglich der Anforderungen für Probennahme, Kalibrierung und Qualitätssicherung.
Das Verfahren ist anwendbar zur Bestimmung der Massenkonzentration von Schwefeldioxid in Außenluft bis 1000 µg/m³. Dieser Konzentrationsbereich entspricht dem Zertifizierungsbereich für die Eignungsprüfung.
ANMERKUNG 1 Je nach Konzentrationsniveau in der Luft können auch andere Bereiche gewählt werden.
ANMERKUNG 2 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 Schwefeldioxid an Standorten, die als ländlich, städtischer Hintergrund, verkehrsbezogen und durch industrielle Quellen beeinflusst klassifiziert sind.
Die Ergebnisse werden in µg/m³ (bei 20 °C und 101,3 kPa) angegeben.
ANMERKUNG 3 1000 µg/m3 an SO2 entsprechen 376 nmol/mol an SO2.
Diese Norm enthält Informationen für verschiedene Nutzergruppen.
Die Abschnitte 5 bis 7 und die Anhänge C und D enthalten allgemeine Informationen über die Grundlagen der Schwefeldioxid-Messung mit einem Ultraviolett-Fluoreszenz-Messgerät sowie über die Probennahme-einrichtung.
Abschnitt 8 und Anhang E richten sich speziell an Prüfinstitute und -laboratorien, die Eignungsprüfungen von Schwefeldioxid-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 Schwefeldioxid-Messgeräts anhand der Eignungsprüfungsergebnisse.
Die Abschnitte 9 bis 11 und die Anhänge F und G richten sich an die Betreiber von Messnetzen, mit denen Schwefeldioxid-Messungen in Luft 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.
Qualité de l'air ambiant - Méthode normalisée pour le mesurage de la concentration en dioxyde de soufre par fluorescence U.V.
La présente Norme Européenne spécifie une méthode de mesurage en continu pour la détermination de la concentration en dioxyde de soufre (SO2) dans l’air ambiant, selon le principe de mesure par fluorescence U.V. La présente norme décrit les caractéristiques de performance et fixe les critères minimaux requis pour sélectionner un analyseur par fluorescence U.V. 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 fixe 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 dioxyde de soufre présent dans l’air ambiant jusqu’à 1 000 µg/m3. Cette plage de concentration représente l’étendue de mesure certifiée pour SO2 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 dioxyde de soufre présent dans l’air ambiant dans les zones classées comme zones rurales, urbaines, 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 1 000 µg/m3 de SO2 correspondent à 376 nmol/mol de SO2.
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 mesurage du dioxyde de soufre à l’aide d’un analyseur par fluorescence U.V. et d’un équipement de prélèvement.
L’Article 8 et l’Annexe E concernent tout particulièrement les organismes et les laboratoires d’essai qui effectuent des essais d’approbation de type des analyseurs de dioxyde de soufre. 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 mesurage de l’analyseur de dioxyde de soufre d’après les résultats de l’essai d’approbation de type.
Les Articles 9 à 11 et les Annexes F et G concernent les réseaux de surveillance effectuant les mesurages pratiques du dioxyde de soufre 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 mesurage sous des conditions de surveillance pratiques.
Zunanji zrak - Standardna metoda za določevanje koncentracije žveplovega dioksida z ultravijolično fluorescenco
Ta evropski standard določa metodo stalnega merjenja za določitev koncentracije žveplovega dioksida v zunanjem zraku na podlagi fluorescentnega ultravijoličnega merilnega principa. Ta standard opisuje lastnosti delovanja in vzpostavlja ustrezna minimalna merila, potrebna za izbiro ustreznega fluorescentnega ultravijoličnega analizatorja s homologacijskimi preizkusi. Vključuje tudi oceno ustreznosti analizatorja za uporabo na specifičnem fiksnem mestu, da se izpolnijo zahteve o kakovosti podatkov, kot je opredeljeno v Prilogi I Direktive 2008/50/ES, ter zahteve med vzorčenjem, kalibriranjem in zagotavljanjem kakovosti za uporabo. Ta metoda velja za določitev masne koncentracije žveplovega dioksida v zunanjem zraku do vrednosti 1.000 μg/m3. Ta razpon koncentracije predstavlja razpon certificiranja za SO2 za homologacijski preizkus. Ta metoda pokriva določitev koncentracij žveplovega dioksida v zunanjem zraku na področjih, ki so uvrščena med podeželska območja, območja v urbanem okolju, prometna območja in lokacije, na katere vplivajo industrijski viri. Rezultati so izraženi v μg/m3 (pri 20 °C in 101,3 kPa). Ta standard vsebuje informacije za različne skupine uporabnikov. Določbe od 5 do 7 ter dodatka C in D vsebujejo splošne informacije o načelih merjenja žveplovega dioksida z ultravijoličnimi fluorescentnimi analizatorji in opremo za vzorčenje. Osrednji predmet obravnave določbe 8 in dodatka E so laboratoriji, ki izvajajo homologacijske preizkuse za analizatorje žveplovega dioksida. Ti razdelki vsebujejo informacije o naslednjem: – pogoji homologacijskega preizkusa, preizkusni postopki in zahteve; – zahteve glede učinkovitosti analizatorja; – ocena rezultatov homologacijskega preizkusa; – ocena negotovosti rezultatov merjenja analizatorja žveplovega dioksida na podlagi rezultatov homologacijskega preizkusa. Osrednji predmet obravnave določb od 9 do 11 ter dodatkov F in G so mreže za spremljanje stanja, ki izvajajo praktične meritve žveplovega dioksida v zunanjem zraku. Ti razdelki vsebujejo informacije o naslednjem: – začetna namestitev analizatorja v mrežo za spremljanje stanja in preizkušanje ustreznosti; – tekoče zagotavljanje kakovosti/nadzor kakovosti; – izračun in poročanje rezultatov merjenja; – ocena negotovosti rezultatov merjenja pod pogoji praktičnega spremljanja.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.SORYHJDAußenluft - Messverfahren zur Bestimmung der Konzentration von Schwefeldioxid mit Ultraviolett-FluoreszenzQualité de l'air ambiant - Méthode normalisée pour le mesurage de la concentration en dioxyde de soufre par fluorescence U.V.Ambient air - Standard method for the measurement of the concentration of sulphur dioxide by ultraviolet fluorescence13.040.20Kakovost okoljskega zrakaAmbient atmospheresICS:Ta slovenski standard je istoveten z:EN 14212:2012SIST EN 14212:2012en,fr,de01-december-2012SIST EN 14212:2012SLOVENSKI
STANDARDSIST EN 14212:20051DGRPHãþD
SIST EN 14212:2012
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14212
August 2012 ICS 13.040.20 Supersedes EN 14212:2005English Version
Ambient air - Standard method for the measurement of the concentration of sulphur dioxide by ultraviolet fluorescence
Qualité de l'air ambiant - Méthode normalisée pour le mesurage de la concentration en dioxyde de soufre par fluorescence U.V.
Luftqualität - Messverfahren zur Bestimmung der Konzentration von Schwefeldioxid mit Ultraviolett-Fluoreszenz This European Standard was approved by CEN on 10 May 2012.
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, 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 United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14212:2012: ESIST EN 14212:2012
EN 14212:2012 (E) 2 Contents Foreword . 41Scope . 52Normative references . 53Terms and definitions . 64Abbreviated terms . 115Principle . 115.1General . 115.2Measuring principle . 115.3Type approval test . 125.4Field operation and quality control . 126Sampling . 136.1General . 136.2Sampling location . 136.3Sampling system . 136.4Control and regulation of sample flow rate . 146.5Sampling pump for the manifold . 147Analyser equipment . 157.1General . 157.2Selective traps for interfering agents . 157.3Optical assembly . 157.4Pressure measurement . 157.5Flow rate indicator . 157.6Sampling pump for the analyser . 167.7Internal sulphur dioxide span source . 167.8Particle filter . 168Type approval of ultraviolet fluorescence sulphur dioxide analysers . 168.1General . 168.2Relevant performance characteristics and performance criteria . 178.3Design change . 188.4Procedures for determination of the performance characteristics during the laboratory test . 198.5Determination of the performance characteristics during the field test . 298.6Type approval and uncertainty calculation . 339Field operation and ongoing quality control . 349.1General . 349.2Suitability evaluation . 34SIST EN 14212:2012
EN 14212:2012 (E) 3 9.3Initial installation . 369.4Ongoing quality assurance/quality control. 379.5Calibration of the analyser. 399.6Checks . 409.7Maintenance . 449.8Data handling and data reports . 459.9Measurement uncertainty . 4510Expression of results . 4611Test reports and documentation . 4611.1Type approval test . 4611.2Field operation . 47Annex A (normative)
Test of lack of fit . 49Annex B (informative)
Sampling equipment. 51Annex C (informative)
Ultraviolet fluorescence analyser . 53Annex D (informative)
Manifold testing . 54Annex E (normative)
Type approval . 56Annex F (informative)
Calculation of uncertainty in field operation at the hourly limit value . 75Annex G (informative)
Calculation of uncertainty in field operation at the daily limit value . 83Annex H (informative)
Calculation of uncertainty in field operation at the annual critical level . 93Annex I (informative)
Significant technical changes . 103Bibliography . 104 SIST EN 14212:2012
EN 14212:2012 (E) 4 Foreword This document (EN 14212:2012) 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 February 2013, and conflicting national standards shall be withdrawn at the latest by February 2013. 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 14212:2005. The technical changes made since EN 14212:2005 are listed in Annex I of this European Standard. 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, 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 14212:2012
EN 14212:2012 (E) 5 1 Scope This European Standard specifies a continuous measurement method for the determination of the concentration of sulphur dioxide present in ambient air based on the ultraviolet fluorescence measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet fluorescence 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 sulphur dioxide present in ambient air up to 1000 µg/m3. This concentration range represents the certification range for SO2 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 sulphur dioxide 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 3 1 000 µg/m3 of SO2 corresponds to 376 nmol/mol of SO2. This standard contains information for different groups of users. Clauses 5 to 7 and Annexes C and D contain general information about the principles of sulphur dioxide measurement by ultraviolet fluorescence analyser and sampling equipment. Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of sulphur dioxide 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 sulphur dioxide analyser based on the type-approval test results. Clauses 9 to 11 and Annexes F and G are directed towards monitoring networks performing the practical measurements of sulphur dioxide 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. 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. SIST EN 14212:2012
EN 14212:2012 (E) 6 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 methods
(ISO 6144) 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 6145-10, 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) EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
(ISO/IEC 17025) ENV 13005:1999, Guide to the expression of uncertainty in measurement 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). Note 2 to entry: Adjustment of a measuring system should not be confused with calibration, which is a prerequisite for adjustment. [SOURCE: JCGM 200:2012 (VIM) [2]] Note 3 to entry: In the context of this standard, adjustment is performed on measurement data rather than on the analyser. 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]] SIST EN 14212:2012
EN 14212:2012 (E) 7
3.3 analyser measuring system 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 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. [SOURCE: JCGM 200:2012 (VIM) [2]] Note 4 to entry
In the context of this standard, 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. 3.6 certification range concentration range for which the analyser is type-approved 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: ENV 13005:1999] 3.9 coverage factor numerical factor used as a multiplier of the combined standard uncertainty in order to obtain an expanded uncertainty [SOURCE: ENV 13005:1999] 3.10 designated 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 SIST EN 14212:2012
EN 14212:2012 (E) 8 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 3,3x(sz/B) where sz is the standard deviation of analyser response at zero measurand concentration (see 8.4.5) and B is the slope of the calibration function [3]. 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. [SOURCE: ENV 13005:1999] Note 3 to entry: For the purpose of this European 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 %. 3.13 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: ENV 13005:1999] 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
SIST EN 14212:2012
EN 14212:2012 (E) 9 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: 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 from one and the same sampling manifold starting at the same time and ending at the same time 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 sulphur dioxide 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; SIST EN 14212:2012
EN 14212:2012 (E) 10 c) at the same monitoring station; d) the period of unattended operation. 3.29 residence time inside the analyser time period for the sampled air to be transported from the inlet of the analyser to the reaction chamber 3.30 residence time in the sampling system time period for the sampled air to be transferred to the inlet of the analyser 3.31 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 a predefined change of the output reading 3.32 sampled air part of ambient air that is transferred through the sampling inlet and sampling system for subsequent measurement 3.33 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-approval testing or to ambient air transferred to the analyser. 3.34 sampling system assembly of components needed to transfer ambient air to the analyser 3.35 short-term drift difference between zero or span readings at the beginning and end of a 12 h period 3.36 standard uncertainty uncertainty of the result of a measurement expressed as a standard deviation
[SOURCE: ENV 13005:1999] 3.37 surrounding temperature temperature of the air directly surrounding the analyser 3.38 total residence time sum of the residence time in the sampling system and the residence time inside the analyser 3.39 type approval decision taken by a designated body that the pattern of an analyser conforms to specified requirements
3.40 type approval test examination of two or more analysers of the same pattern which are submitted by a manufacturer to a designated body including the tests necessary for approval of the pattern SIST EN 14212:2012
EN 14212:2012 (E) 11 3.41 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: ENV 13005:1999] 4 Abbreviated terms FEP
perfluoro-ethylene-propylene;
MFC mass flow controller;
PTFE polytetrafluoroethylene. 5 Principle 5.1 General This standard describes the method for measurement of the concentration of sulphur dioxide in ambient air by means of ultraviolet fluorescence. The requirements, the specific components of the ultraviolet fluorescence 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 test 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 15% for fixed measurements or 25 % for indicative measurements, as 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 UV (ultraviolet) fluorescence is based on the emission of light by SO2 molecules excited by UV radiation when they return to their ground state: The first reaction step is: SO2 + hν → SO2* (1) In the second step the excited SO2* molecule returns to its ground state, emitting an energy hν’ according to the reaction: SO2* → SO2 + hν’ (UV) (2) The intensity of the fluorescence radiation is proportional to the number of SO2 molecules in the detection volume and is therefore proportional to the concentration of SO2. Therefore: 2SOckF×= (3) where F is the intensity of fluorescence radiation; SIST EN 14212:2012
EN 14212:2012 (E) 12 k is the factor of proportionality; 2SOc is the concentration of SO2. Before entering the fluorescence analyser, the air sample is passed through a filter in order to exclude interferences caused by contamination with particles. The sampled air is scrubbed to remove any interference by aromatic hydrocarbons that may be present. A hydrocarbon scrubber device is used to achieve this.
The sampled air is then introduced into a reaction chamber
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