SIST EN 14792:2017
(Main)Stationary source emissions - Determination of mass concentration of nitrogen oxides - Standard reference method: chemiluminescence
Stationary source emissions - Determination of mass concentration of nitrogen oxides - Standard reference method: chemiluminescence
This European Standard specifies the standard reference method (SRM) based on the chemiluminescence principle for the determination of the nitrogen oxides (NOx) in flue gases emitted to the atmosphere from ducts and stacks. It includes the sampling and the gas conditioning system, as well as the analyser.
This European Standard specifies the characteristics to be determined and the performance criteria to be fulfilled by measuring systems based on this measurement method. It applies for periodic monitoring and for the calibration or control of automatic measuring systems (AMS) permanently installed on a stack, for regulatory or other purposes.
This European Standard specifies criteria for demonstration of equivalence of an alternative method to the SRM by application of prEN 14793.
This European standard has been validated during field tests on waste incineration, co-incineration and large combustion installations and on a recognized test-bench. It has been validated for sampling periods of 30 min in the range of 0 mg/m3 to 1 300 mg/m3 of NO2 for large combustion plants and 0 mg/m3 to 400 mg/m3 of NO2 for waste incineration, according to emission limit values (ELV) laid down in the Directive 2010/75/EC.
The ELV for NOx (NO + NO2) in EU directives are expressed in mg/m3 of NO2 on a dry basis, at a specified value for oxygen and at reference conditions (273 K and 101,3 kPa).
NOTE The characteristics of installations, the conditions during field tests and the values of repeatability and reproducibility in the field are given in Annex F.
Emissionen aus stationären Quellen - Bestimmung der Massenkonzentration von Stickstoffoxiden - Standardreferenzverfahren: Chemilumineszenz
Diese Europäische Norm legt das Standardreferenzverfahren (SRM) auf Basis des Chemilumineszenz-Verfahrens zur Bestimmung der Stickstoffoxide (NOx) in Abgasen, die aus Abgaskanälen in die Atmosphäre emittiert werden, fest. Es beinhaltet die Einrichtungen zur Probenahme und zur Probengasaufbereitung sowie das Analysegerät.
Diese Europäische Norm legt zu bestimmende Verfahrenskenngrößen und Mindestanforderungen fest, die von portablen automatischen Messeinrichtungen (P AMS) auf Basis dieses Messverfahrens eingehalten werden müssen. Sie gilt für wiederkehrende Messungen und für die Kalibrierung oder Überprüfung von automatischen Messeinrichtungen (AMS), die aus gesetzgeberischen oder anderen Gründen stationär an einem Abgaskanal installiert sind.
Diese Europäische Norm legt Anforderungen zum Nachweis der Gleichwertigkeit von Alternativverfahren (AM) mit dem Standardreferenzverfahren (SRM) durch Anwendung der EN 14793:2017 fest.
Diese Europäische Norm wurde in Feldversuchen an Abfallverbrennungsanlagen, Mitverbrennungsanlagen und Großfeuerungsanlagen sowie an einem anerkannten Prüfstand validiert. Sie wurde mit Probenahmedauern von 30 min für NOx-Konzentrationen im Bereich von 0 mg/m3 bis 1 300 mg/m3 für Großfeuerungsanlagen und im Bereich von 0 mg/m3 bis 400 mg/m3 für Abfallverbrennungsanlagen, jeweils gemessen als NO2, entsprechend den in der Richtlinie 2010/75/EU geforderten Emissionsgrenzwerten (ELV) validiert.
In den EU-Richtlinien wird der Grenzwert für NOx (NO + NO2) gemessen als NO2 in Milligramm je Kubikmeter (mg/m3) für trockenes Gas bei einem Bezugssauerstoffgehalt und Normbedingungen (273 K und 101,3 kPa) angegeben.
ANMERKUNG Die Einzelheiten der Anlagen, die Bedingungen bei den Feldversuchen und die Werte der Wiederhol- und der Vergleichpräzision im Feld werden in Anhang A aufgeführt.
Emissions de sources fixes - Détermination de la concentration massique des oxydes d'azote - Méthode de référence normalisée : chimiluminescence
La présente Norme européenne spécifie la méthode de référence normalisée (SRM) basée sur le principe de chimiluminescence pour la détermination des oxydes d'azote (NOx) des effluents gazeux émis dans l'atmosphère par les conduits et cheminées. Elle inclut le système de prélèvement et de conditionnement du gaz ainsi que l'analyseur.
La présente Norme européenne spécifie les caractéristiques devant être déterminées et les critères de performance devant être remplis par les systèmes de mesurage fondés sur cette méthode de mesurage. Elle s'applique à la surveillance périodique et à l'étalonnage ou au contrôle des systèmes de mesurage automatisés (AMS, Automatic Measuring Systems) installés à demeure sur une cheminée, à des fins réglementaires ou à d'autres fins.
La présente Norme européenne spécifie les critères permettant de démontrer l'équivalence entre une méthode « alternative » et la méthode de référence normalisée par l'application du prEN 14793.
La présente Norme européenne a été validée au cours d'essais sur site pratiqués sur des installations destinées à l'incinération des déchets, à la coincinération et sur de grandes installations de combustion ainsi que sur un banc d'essai reconnu. Elle a été validée pour des périodes de prélèvement de 30 min, dans la gamme comprise entre 0 mg/m3 et 2 000 mg/m3 de NO2 pour de grandes installations de combustion et entre 0 mg/m3 à 400 mg/m3 of NO2 pour l'incinération des déchets, conformément aux valeurs limites d'émission (VLE) spécifiées dans la Directive 2010/75/CE.
Les VLE des Directives UE pour NOx (NO + NO2) sont exprimées en mg/m3 de NO2 sur sec, à une valeur spécifiée de l'oxygène et dans les conditions de référence (273 K et 101,3 kPa).
NOTE Les caractéristiques des installations, les conditions des essais sur site et les valeurs de répétabilité et de reproductibilité sur site sont indiquées à l'Annexe F.
Emisije nepremičnih virov - Določevanje masne koncentracije dušikovih oksidov - Standardna referenčna metoda: kemiluminiscenca
Ta evropski standard določa standardno referenčno metodo (SRM) na podlagi kemoluminiscence za določanje dušikovih oksidov (NOx) v dimnih plinih, ki prehajajo v ozračje iz vodov in odvodnikov. Vključuje sistem za vzorčenje in kondicioniranje plinov ter tudi analizator.
Ta evropski standard določa lastnosti in merila zmogljivosti, ki jih morajo izpolnjevati merilni sistemi na podlagi te merilne metode. Uporablja se za redno spremljanje in kalibracijo ali nadzor avtomatskih merilnih sistemov (AMS), ki so trajno nameščeni na odvodnik, in sicer za zakonske ter druge namene.
Ta evropski standard določa merila za prikaz enakovrednosti alternativne metode standardni referenčni metodi z uporabo standarda prEN 14793.
Ta evropski standard je bil potrjen med preskusi sežiganja odpadkov, sosežiga in velikih kurilnih naprav na terenu ter na ustrezni preskusni mizi. Potrjen je bil za 30-minutna obdobja vzorčenja v razponu od 0 mg/m3 do 1300 mg/m3 NO2 za velike kurilne naprave in od 0 mg/m3 do 400 mg/m3 NO2 za sežig odpadkov glede na mejne vrednosti emisij (ELV), opredeljene v Direktivi 2010/75/ES.
Mejne vrednosti emisij za NOx (NO + NO2) v direktivah EU so izražene v mg/m3 NO2 na suhi osnovi pri podani vrednosti kisika in referenčnih pogojih (273 K in 101,3 kPa).
OPOMBA: Lastnosti naprav, pogoji med preskusi na terenu ter vrednosti ponovljivosti in reprodukcije na terenu so podani v dodatku F.
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Emissionen aus stationären Quellen - Bestimmung der Massenkonzentration von Stickstoffoxiden - Standardreferenzverfahren: ChemilumineszenzEmissions de sources fixes - Détermination de la concentration massique des oxydes d'azote - Méthode de référence normalisée : chimiluminescenceStationary source emissions - Determination of mass concentration of nitrogen oxides - Standard reference method: chemiluminescence13.040.40Stationary source emissionsICS:Ta slovenski standard je istoveten z:EN 14792:2017SIST EN 14792:2017en,fr,de01-marec-2017SIST EN 14792:2017SLOVENSKI
STANDARDSIST EN 14792:20061DGRPHãþD
SIST EN 14792:2017
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14792
January
t r s y ICS
s uä r v rä v r Supersedes EN
s v y { tã t r r wEnglish Version
Stationary source emissions æ Determination of mass concentration of nitrogen oxides æ Standard reference methodã chemiluminescence Emissions de sources fixes æ Détermination de la concentration massique des oxydes d 5azote æ Méthode de référence normalisée ã chimiluminescence
Emissionen aus stationären Quellen æ Bestimmung der Massenkonzentration von Stickstoffoxiden æ Standardreferenzverfahrenã Chemilumineszenz This European Standard was approved by CEN on
t x September
t r s xä
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 Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
9
t r s y CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v y { tã t r s y ESIST EN 14792:2017
EN 14792:2017 (E) 2 Contents Page
European foreword . 5 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 7 4 Symbols and abbreviations . 13 4.1 Symbols . 13 4.2 Abbreviated terms . 14 5 Principle . 14 5.1 General . 14 5.2 Measuring principle . 14 6 Description of the measuring system . 15 6.1 General . 15 6.2 Sampling and sample gas conditioning system . 16 6.2.1 Sampling probe . 16 6.2.2 Filter . 17 6.2.3 Sample gas line . 17 6.2.4 Sample gas conditioning system . 17 6.2.5 Sample gas pump . 18 6.2.6 Secondary filter . 18 6.2.7 Flow controller and flow meter . 18 6.3 Analyser equipment . 18 6.3.1 General . 18 6.3.2 Converter . 19 6.3.3 Ozone generator . 19 6.3.4 Reaction chamber . 19 6.3.5 Optical filter . 19 6.3.6 Photomultiplier tube . 20 6.3.7 Ozone removal . 20 7 Performance characteristics of the SRM . 20 8 Suitability of the measuring system to the measurement task . 21 9 Field operation . 22 9.1 Measurement planning . 22 9.2 Sampling strategy. 22 9.2.1 General . 22 9.2.2 Measurement section and measurement plane . 22 9.2.3 Minimum number and location of measurement points . 22 9.2.4 Measurement ports and working platform . 22 9.3 Choice of the measuring system . 23 9.4 Setting of the measuring system on site . 23 9.4.1 General . 23 9.4.2 Preliminary zero and span check, and adjustments . 23 9.4.3 Zero and span checks after measurement . 24 SIST EN 14792:2017
EN 14792:2017 (E) 3 10 Ongoing quality control . 25 10.1 General . 25 10.2 Frequency of checks . 25 11 Expression of results . 26 12 Equivalence of an alternative method . 27 13 Measurement report . 27 Annex A (informative)
Validation of the method in the field . 28 A.1 General . 28 A.2 Characteristics of installations . 28 A.3 Repeatability and reproducibility in the field . 29 A.3.1 General . 29 A.3.2 Repeatability . 30 A.3.3 Reproducibility . 31 Annex B (informative)
Sampling and conditioning configurations . 32 Annex C (normative)
Determination of conversion efficiency . 33 C.1 General . 33 C.2 First method: cylinder gases for calibration . 33 C.3 Second method: gaseous phase titration . 33 Annex D (informative)
Examples of different types of converters . 35 D.1 Quartz converter . 35 D.2 Low temperature converter (molybdenum) . 35 D.3 Stainless steel converter . 35 Annex E (informative)
Calculation of the uncertainty associated with a concentration expressed for dry gas and at an oxygen reference concentration . 36 E.1 Uncertainty associated with a concentration expressed on dry gas . 36 E.2 Uncertainty associated with a concentration expressed at a oxygen reference concentration . 38 Annex F (informative)
Example of assessment of compliance of chemiluminescence method for NOx with requirements on emission measurements . 40 F.1 General . 40 F.2 Elements required for the uncertainty determinations . 40 F.2.1 Model equation . 40 F.2.2 Combined uncertainty . 41 F.2.3 Expanded uncertainty . 41 F.2.4 Determination of uncertainty contributions in case of rectangular distributions . 43 F.2.5 Determination of uncertainty contributions by use of sensitivity coefficients . 44 F.3 Example of an uncertainty calculation. 44 F.3.1 Site specific conditions . 44 SIST EN 14792:2017
EN 14792:2017 (E) 4 F.3.2 Performance characteristics of the method . 45 F.3.3 Calculation of concentration values . 46 F.3.4 Determination of the uncertainty contributions . 47 F.3.5 Result of uncertainty calculation . 50 F.3.5.1 Standard uncertainties . 50 F.3.5.2 Combined uncertainty . 51 F.3.5.3 Expanded uncertainty . 52 F.3.5.4 Evaluation of the compliance with the required measurement quality . 52 Annex G (informative) Example of correction of data from drift effect . 53 Annex H (informative)
Significant technical changes . 55 Bibliography . 56
SIST EN 14792:2017
EN 14792:2017 (E) 5 European foreword This document (EN 14792:2017) has been prepared by Technical Committee CEN/TC 264 “Air quality”, the secretariat of which is held by DIN. This document supersedes EN 14792:2005. 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 July 2017, and conflicting national standards shall be withdrawn at the latest by July 2017. 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. Annex H provides details of significant technical changes between this document and the previous edition. 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 14792:2017
EN 14792:2017 (E) 6 1 Scope This European Standard specifies the standard reference method (SRM) based on the chemiluminescence principle for the determination of the nitrogen oxides (NOx) in flue gases emitted to the atmosphere from ducts and stacks. It includes the sampling and the gas conditioning system, as well as the analyser.
This European Standard specifies the characteristics to be determined and the performance criteria to be fulfilled by portable automated measuring systems (P-AMS) based on this measurement method. It applies for periodic monitoring and for the calibration or control of automated measuring systems (AMS) permanently installed on a stack, for regulatory or other purposes.
This European Standard specifies criteria for demonstration of equivalence of an alternative method to the SRM by application of EN 14793:2017. This European Standard has been validated during field tests on waste incineration, co-incineration and large combustion installations and on a recognized test-bench. It has been validated for sampling periods of 30 min in the range of 0 mg/m3 to 1 300 mg/m3 of NOx for large combustion plants and 0 mg/m3 to 400 mg/m3 of NOx for waste incineration, according to emission limit values (ELV) laid down in the Directive 2010/75/EU. The ELV for NOx (NO + NO2) in EU Directives is expressed in mg/m3 of NO2 on a dry basis, at a specified value for oxygen and at standard conditions (273 K and 101,3 kPa). NOTE The characteristics of installations, the conditions during field tests and the values of repeatability and reproducibility in the field are given in Annex A. 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 14793:2017, Stationary source emission – Demonstration of equivalence of an alternative method with a reference method EN 15259:2007, Air quality - Measurement of stationary source emissions - Requirements for measurement sections and sites and for the measurement objective, plan and report EN 15267-4:2017, Air quality — Certification of automated measuring systems — Part 4: Performance criteria and test procedures for automated measuring systems for periodic measurements of emissions from stationary sources EN ISO 14956:2002, Air quality - Evaluation of the suitability of a measurement procedure by comparison with a required measurement uncertainty (ISO 14956:2002) ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) SIST EN 14792:2017
EN 14792:2017 (E) 7 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE In this European Standard, NOx is defined as the sum of NO and NO2. The mass concentration of NOx is expressed as the equivalent NO2 concentration in milligrams per cubic metre at standard conditions. 3.1 standard reference method
SRM reference method prescribed by European or national legislation
[SOURCE: EN 15259:2007] 3.2 reference method RM measurement method taken as a reference by convention, which gives the accepted reference value of the measurand Note 1 to entry: A reference method is fully described. Note 2 to entry: A reference method can be a manual or an automated method. Note 3 to entry: Alternative methods can be used if equivalence to the reference method has been demonstrated. [SOURCE: EN 15259:2007] 3.3 measurement method method described in a written procedure containing all the means and procedures required to sample and analyse, namely: field of application, principle and/or reactions, definitions, equipment, procedures, presentation of results, and other requirements and measurement report [SOURCE: EN 14793:2017] 3.4 alternative method
AM
measurement method which complies with the criteria given by this European Standard with respect to the reference method
Note 1 to entry: An alternative method can consist of a simplification of the reference method. [SOURCE: EN 14793:2017] 3.5 measuring system set of one or more measuring instruments and often other devices, including any reagent and supply, assembled and adapted to give information used to generate measured quantity values within specified intervals for quantities of specified kinds [SOURCE: JCGM 200:2012] SIST EN 14792:2017
EN 14792:2017 (E) 8 3.6 automated measuring system AMS entirety of all measuring instruments and additional devices for obtaining a result of measurement Note 1 to entry: Apart from the actual measuring device (the analyser), an AMS includes facilities for taking samples (e.g. probe, sample gas lines, flow meters and regulator, delivery pump) and for sample conditioning (e.g. dust filter, pre-separator for interferents, cooler, converter). This definition also includes testing and adjusting devices that are required for functional checks and, if applicable, for commissioning. Note 2 to entry: The term “automated measuring system” (AMS) is typically used in Europe. The term “continuous emission monitoring system” (CEMS) is also typically used in the UK and USA. [SOURCE: EN 15267-4:2017] 3.7 portable automated measuring system P-AMS automated measuring system which is in a condition or application to be moved from one to another measurement site to obtain measurement results for a short period Note 1 to entry: The measurement period is typically 8 h for a day.
Note 2 to entry: The P-AMS can be configured at the measurement site for the special application but can be also set-up in a van or mobile container. The probe and the sample gas lines are installed often just before the measurement task is started.
[SOURCE: EN 15267-4:2017] 3.8 calibration
set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring method or measuring system, and the corresponding values given by the applicable reference
Note 1 to entry: In case of automated measuring system (AMS) permanently installed on a stack the applicable reference is the standard reference method (SRM) used to establish the calibration function of the AMS. Note 2 to entry: Calibration should not be confused with adjustment of a measuring system. 3.9 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: The adjustment can be made directly on the instrument or using a suitable calculation procedure. 3.10 span gas test gas used to adjust and check a specific point on the response line of the measuring system SIST EN 14792:2017
EN 14792:2017 (E) 9 3.11 measurand particular quantity subject to measurement
[SOURCE: EN 15259:2007] Note 1 to entry:
The measurand is a quantifiable property of the stack gas under test, for example mass concentration of a measured component, temperature, velocity, mass flow, oxygen content and water vapour content. 3.12 interference negative or positive effect upon the response of the measuring system, due to a component of the sample that is not the measurand 3.13 influence quantity quantity that is not the measurand but that affects the result of the measurement Note 1 to entry: Influence quantities are e.g. presence of interfering gases; ambient temperature, pressure of the gas sample. 3.14 ambient temperature
temperature of the air around the measuring device 3.15 emission limit value ELV limit value given in regulations such as EU Directives, ordinances, administrative regulations, permits, licences, authorisations or consents Note 1 to entry: ELV can be stated as concentration limits expressed as half-hourly, hourly and daily averaged values, or mass flow limits expressed as hourly, daily, weekly, monthly or annually aggregated values. 3.16 measurement site place on the waste gas duct in the area of the measurement plane(s) consisting of structures and technical equipment, for example working platforms, measurement ports, energy supply
Note 1 to entry: Measurement site is also known as sampling site. [SOURCE: EN 15259:2007] 3.17 measurement plane plane normal to the centreline of the duct at the sampling position Note 1 to entry: Measurement plane is also known as sampling plane. [SOURCE: EN 15259:2007] SIST EN 14792:2017
EN 14792:2017 (E) 10 3.18 measurement port opening in the waste gas duct along the measurement line, through which access to the waste gas is gained Note 1 to entry: Measurement port is also known as sampling port or access port. [SOURCE: EN 15259:2007] 3.19 measurement line line in the measurement plane along which the measurement points are located, bounded by the inner duct wall Note 1 to entry: Measurement line is also known as sampling line. [SOURCE: EN 15259:2007] 3.20 measurement point position in the measurement plane at which the sample stream is extracted or the measurement data are obtained directly
Note 1 to entry: Measurement point is also known as sampling point. [SOURCE: EN 15259:2007] 3.21 performance characteristic one of the quantities (described by values, tolerances, range) assigned to equipment in order to define its performance 3.22 response time duration between the instant when an input quantity value of a measuring instrument or measuring system is subjected to an abrupt change between two specified constant quantity values and the instant when a corresponding indication settles within specified limits around its final steady value
Note 1 to entry: By convention time taken for the output signal to pass from 0 % to 90 % of the final variation of indication. 3.23 short-term zero drift difference between two zero readings at the beginning and at the end of the measurement period 3.24 short-term span drift difference between two span readings at the beginning and at the end of the measurement period SIST EN 14792:2017
EN 14792:2017 (E) 11 3.25 lack of fit systematic deviation, within the measurement range, between the measurement result obtained by applying the calibration function to the observed response of the measuring system measuring test gases and the corresponding accepted value of such test gases Note 1 to entry: Lack of fit can be a function of the measurement result. Note 2 to entry: The expression “lack of fit” is often replaced in everyday language by “linearity” or “deviation from linearity”. 3.26 repeatability in the laboratory closeness of the agreement between the results of successive measurements of the same measurand carried out under the same conditions of measurement Note 1 to entry: Repeatability conditions include: — same measurement method; — same laboratory; — same measuring system, used under the same conditions; — same location; — repetition over a short period of time. Note 2 to entry: Repeatability may be expressed quantitatively in terms of the dispersion characteristics of the results. Note 3 to entry: In this European Standard the repeatability is expressed as a value with a level of confidence of 95 %. SIST EN 14792:2017
EN 14792:2017 (E) 12 3.27 repeatability in the field closeness of the agreement between the results of simultaneous measurements of the same measurand carried out with two sets of equipment under the same conditions of measurement Note 1 to entry: These conditions include: — same measurement method; — two sets of equipment, the performance of which fulfils the requirements of the measurement method,
used under the same conditions; — same location; — implemented by the same laboratory; — typically calculated on short periods of time in order to avoid the effect of changes of influence
parameters (e.g. 30 min). Note 2 to entry: Repeatability may be expressed quantitatively in terms of the dispersion characteristics of the results. Note 3 to entry: In this European Standard the repeatability under field conditions is expressed as a value with a level of confidence of 95 %. 3.28 reproducibility in the field
closeness of the agreement between the results of simultaneous measurements of the same measurand carried out using several sets of equipment under the same conditions of measu
...
SLOVENSKI STANDARD
oSIST prEN 14792:2015
01-januar-2015
(PLVLMHQHSUHPLþQLKYLURY'RORþHYDQMHPDVQHNRQFHQWUDFLMHGXãLNRYLKRNVLGRY
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Stationary source emissions - Determination of mass concentration of nitrogen oxides -
Standard reference method: chemiluminescence
Emissionen aus stationären Quellen - Bestimmung der Massenkonzentration von
Stickstoffoxiden - Standardreferenzverfahren: Chemilumineszenz
Emissions de sources fixes - Détermination de la concentration massique des oxydes
d'azote - Méthode de référence normalisée : chimiluminescence
Ta slovenski standard je istoveten z: prEN 14792
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
oSIST prEN 14792:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 14792:2015
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oSIST prEN 14792:2015
EUROPEAN STANDARD
DRAFT
prEN 14792
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2014
ICS 13.040.40 Will supersede EN 14792:2005
English Version
Stationary source emissions - Determination of mass
concentration of nitrogen oxides - Standard reference method:
chemiluminescence
Emissions de sources fixes - Détermination de la Emissionen aus stationären Quellen - Bestimmung der
concentration massique des oxydes d'azote - Méthode de Massenkonzentration von Stickstoffoxiden -
référence normalisée : chimiluminescence Standardreferenzverfahren: Chemilumineszenz
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 264.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14792:2014 E
worldwide for CEN national Members.
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oSIST prEN 14792:2015
prEN 14792:2014 (E)
Contents
Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Principle .9
5 Description of measuring equipment . 11
6 Performance characteristics of the SRM . 15
7 Suitability of the measuring system to the measurement task . 16
8 Field operation . 17
9 Ongoing quality control . 20
10 Expression of results . 21
11 Equivalence of an alternative method . 22
12 Test report . 22
Annex A (informative) Four different sampling and conditioning configurations . 23
Annex B (normative) Determination of conversion efficiency . 24
Annex C (informative) Examples of different types of converters . 26
Annex D (informative) Calculation of the uncertainty associated with a concentration
expressed for dry gas and at an oxygen reference concentration . 27
Annex E (informative) Example of assessment of compliance of chemiluminescence method for
NO with requirements on emission measurements . 31
x
Annex F (informative) Procedure of correction of data from drift effect . 44
Annex G (informative) Evaluation of the method in the field . 46
Annex H (informative) Significant technical changes . 50
Bibliography . 51
2
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oSIST prEN 14792:2015
prEN 14792:2014 (E)
Foreword
This document (prEN 14792:2014) has been prepared by Technical Committee CEN/TC 264 “Air quality”, the
secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 14792:2005.
Annex H provides details of significant technical changes between this document and the previous edition.
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1 Scope
This European Standard specifies the standard reference method (SRM) based on the chemiluminescence
principle for the determination of the nitrogen oxides (NO ) in flue gases emitted to the atmosphere from ducts
x
and stacks. It includes the sampling and the gas conditioning system, as well as the analyser.
This European Standard specifies the characteristics to be determined and the performance criteria to be
fulfilled by measuring systems based on this measurement method. It applies for periodic monitoring and for
the calibration or control of automatic measuring systems (AMS) permanently installed on a stack, for
regulatory or other purposes.
This European Standard specifies criteria for demonstration of equivalence of an alternative method to the
SRM by application of prEN 14793.
This European standard has been validated during field tests on waste incineration, co-incineration and large
combustion installations and on a recognized test-bench. It has been validated for sampling periods of 30 min
3 3 3 3
in the range of 0 mg/m to 1 300 mg/m of NO for large combustion plants and 0 mg/m to 400 mg/m of
2
NO for waste incineration, according to emission limit values (ELV) laid down in the Directive 2010/75/EC.
2
3
The ELV for NO (NO + NO ) in EU directives are expressed in mg/m of NO on a dry basis, at a specified
x 2 2
value for oxygen and at reference conditions (273 K and 101,3 kPa).
NOTE The characteristics of installations, the conditions during field tests and the values of repeatability and
reproducibility in the field are given in Annex F.
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.
prEN 14793:2014, Stationary source emission – Demonstration of equivalence of an alternative method with a
reference method
EN 15259:2007, Air quality — Measurement of stationary source emissions — Requirements for
measurement sections and sites and for the measurement objective, plan and report
EN 15267-3:2007, Air quality — Certification of automated measuring systems — Part 3: Performance criteria
and test procedures for automated measuring systems for monitoring emissions from stationary sources
EN ISO 14956:2002, Air quality — Evaluation of the suitability of a measurement procedure by comparison
with a required measurement uncertainty
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.
NOTE In this European Standard, NO is defined as the sum of NO and NO . The mass concentration of NO is
x 2 x
expressed as the equivalent NO concentration in milligrams per cubic metre at normal conditions.
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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
[SOURCE: JCGM 200:2012]
Note 1 to entry: The adjustment can be made directly on the instrument or using a suitable calculation procedure.
3.2
ambient temperature
temperature of the air around the measuring device
3.3
automated measuring system
AMS
measuring system permanently installed on site for continuous monitoring of emissions or measurement of
peripheral parameters
Note 1 to entry: An AMS is a method which is traceable to a reference method.
Note 2 to entry: Apart from the analyser, an AMS includes facilities for taking samples (e.g. probe, sample gas lines,
flow meters, regulators, delivery pumps) and for sample conditioning (e.g. dust filter, moisture removal devices,
converters, diluters). This definition also includes testing and adjusting devices that are required for regular functional
checks.
[SOURCE: FprEN 14181:2014]
3.4
calibration of an AMS
establishment of the statistical relationship between values of the measurand indicated by the automated
measuring system (AMS) and the corresponding values given by the standard reference method (SRM) used
during the same period of time and giving a representative measurement on the same measurement plane
Note 1 to entry: The result of calibration permits to establish the relationship between the values of the SRM and the
AMS (calibration function).
3.5
conversion efficiency
percentage of NO present in the sample gas converted to NO by the converter
2
3.6
zero drift
difference between two zero readings at the beginning and at the end of a measuring period
3.7
span drift
difference between two span readings at the beginning and at the end of a measuring period
3.8
emission limit value
ELV
emission limit value according to EU Directives on the basis of 30 min, one hour or one day
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3.9
influence quantity
quantity that is not the measurand but that affects the result of the measurement
Note 1 to entry: Influence quantities are e.g. ambient temperature, atmospheric pressure, presence of interfering gases
in the flue gas matrix or pressure of the gas sample.
3.10
interference
negative or positive effect upon the response of the measuring system, due to a component of the sample that
is not the measurand
3.11
lack of fit
systematic deviation within the range of application between the measurement result obtained by applying the
calibration function to the observed response of the measuring system measuring test gases and the
corresponding accepted value of such test gases
Note 1 to entry: Lack of fit may be a function of the measurement result.
Note 2 to entry: The expression “lack of fit” is often replaced in everyday language by "linearity" or "deviation from
linearity".
3.12
measurand
quantity intended to be measured
[SOURCE: JCGM 200:2012]
3.13
measurement plane
plane normal to the centreline of the duct at the sampling position
Note 1 to entry: Measurement plane is also known as sampling plane.
[SOURCE: EN 15259:2007]
3.14
measurement point
position in the measurement plane at which the sample stream is extracted or the measurement data are
obtained directly
Note 1 to entry: Measurement point is also known as sampling point.
[SOURCE: EN 15259:2007]
3.15
measurement site
place on the waste gas duct in the area of the measurement plane(s) consisting of structures and technical
equipment, for example working platforms, measurement ports, energy supply
Note 1 to entry: Measurement site is also known as sampling site.
[SOURCE: EN 15259:2007]
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3.16
measuring system
set of one or more measuring instruments and often other devices, including any reagent and supply,
assembled and adapted to give information used to generate measured quantity values within specified
intervals for quantities of specified kinds
[SOURCE: JCGM 200:2012]
3.17
performance characteristic
one of the quantities (described by values, tolerances, range…) assigned to equipment in order to define its
performance
3.18
reference method
RM
measurement method taken as a reference by convention, which gives the accepted reference value of the
measurand
Note 1 to entry: A reference method is fully described.
Note 2 to entry: A reference method can be a manual or an automated method.
Note 3 to entry: Alternative methods can be used if equivalence to the reference method has been demonstrated.
[SOURCE: EN 15259:2007]
3.19
standard reference method
SRM
reference method prescribed by European or national legislation
[SOURCE: EN 15259:2007]
3.20
repeatability in the laboratory
closeness of the agreement between the results of successive measurements of the same measurand carried
out under the same conditions of measurement
Note 1 to entry: Repeatability conditions include:
same measurement procedure;
same laboratory;
same measuring instrument, used under the same conditions;
same location;
repetition over a short period of time.
Note 2 to entry: Repeatability may be expressed quantitatively in terms of the dispersion characteristics of the results.
Note 3 to entry: In this European Standard the repeatability is expressed as a value with a level of confidence of 95 %.
3.21
repeatability in the field
closeness of the agreement between the results of simultaneous measurements of the same measurand
carried out with two sets of equipment under the same conditions of measurement
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Note 1 to entry: These conditions include:
same measurement procedure;
two sets of equipment, the performance of which fulfils the requirements of the reference method, used under the
same conditions;
same location;
implemented by the same laboratory;
typically calculated on short periods of time in order to avoid the effect of changes of influence parameters (e.g.
30 min).
Note 2 to entry: Repeatability may be expressed quantitatively in terms of the dispersion characteristics of the results.
Note 3 to entry: In this European Standard the repeatability under field conditions is expressed as a value with a level
of confidence of 95 %.
3.22
reproducibility in the field
closeness of the agreement between the results of simultaneous measurements of the same measurand
carried out using several sets of equipment under the same conditions of measurement
Note 1 to entry: These conditions are called field reproducibility conditions and include:
same measurement procedure;
several sets of equipment, the performance of which fulfils the requirements of the reference method, used under the
same conditions;
same location;
implemented by several laboratories.
Note 2 to entry: Reproducibility may be expressed quantitatively in terms of the dispersion characteristics of the
results.
Note 3 to entry: In this European Standard the reproducibility under field conditions is expressed as a value with a level
of confidence of 95 %.
3.23
residence time in the measuring system
time period for the sampled gas to be transported from the inlet of the probe to the inlet of the measurement
cell
3.24
response time
duration between the instant when an input quantity value of a measuring instrument or measuring system is
subjected to an abrupt change between two specified constant quantity values and the instant when a
corresponding indication settles within specified limits around its final steady value
Note 1 to entry: By convention time taken for the output signal to pass from 0 % to 90 % of the final change.
[SOURCE: JCGM 200:2012]
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3.25
span gas
test gas used to adjust and check a specific point on the response line of the measuring system
Note 1 to entry: This concentration is often chosen around 80 % of the upper limit of the range.
3.26
uncertainty
parameter associated with the result of a measurement, that characterises the dispersion of the values that
could reasonably be attributed to the measurand
3.27
standard uncertainty
u
uncertainty of the result of a measurement expressed as a standard deviation
3.28
combined uncertainty
u
c
standard uncertainty attached to the measurement result calculated by combination of several standard
uncertainties according to the principles laid down in ISO/IEC Guide 98-3 (GUM)
3.29
expanded uncertainty
U
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
U= k× u
Note 1 to entry: In this European Standard, the expanded uncertainty is calculated with a coverage factor of k = 2, and
with a level of confidence of 95 %.
Note 2 to entry: The expression overall uncertainty is sometimes used to express the expanded uncertainty.
3.30
uncertainty budget
calculation table combining all the sources of uncertainty according to EN ISO 14956 or ISO/IEC Guide 98-3
in order to calculate the combined uncertainty of the method at a specified value
4 Principle
4.1 General
This European Standard describes the standard reference method (SRM) for sampling and determining NO ,
x
NO and NO concentrations in flue gases emitted to atmosphere from ducts and stacks by means of an
2
automatic analyser using chemiluminescence absorption principle. The specific components and the
requirements for the sampling system and the chemiluminescence analyser are described in Clause 6. A
number of performance characteristics, together with associated minimum performance criteria are specified
for the analyser. These performance characteristics and the combined uncertainty of the method shall meet
the performance criteria given in this European Standard. Requirements and recommendations for quality
assurance and quality control are given for measurements in the field (see Clause 9).
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4.2 Measuring principle
The principle of chemiluminescence to measure NO is based on the following reaction between nitrogen
x
monoxide and ozone:
2 NO+ 2 O ⇒ NO + NO *+2 O
3 2 2 2
NO *⇒ NO + hν
2 2
Some of the NO created during the reaction of NO and O is in an excited state. When returning to the basic
2 3
state, these NO molecules can radiate light, the intensity of which depends on the NO content and is
2
influenced by the pressure and presence of other gases.
In a chemiluminescence analyser, gas is sampled through a sampling line and fed at a constant flow rate into
the reaction chamber of the analyser, where it is mixed with an excess of ozone for the determination of
nitrogen oxide only. The emitted radiation (chemiluminescence) is proportional to the amount of NO present in
the sampled gas. The emitted radiation is filtered by means of a selective optical filter and converted into an
electric signal by means of a photomultiplier tube.
For the determination of the amount of nitrogen dioxide, the sampled gas is fed through a converter where the
nitrogen dioxide is reduced to nitrogen monoxide and analysed in the same way as previously described. The
electric signal obtained from the photomultiplier tube is proportional to the sum of concentrations of nitrogen
dioxides and nitrogen monoxides. The amount of nitrogen dioxide is calculated from the difference between
this concentration and that obtained for nitrogen monoxide only (when the sampled gas has not passed
through the converter).
When a dual type analyser is used, both NO and NO results are determined continuously. On the contrary,
x
with a single type analyser, the reaction chamber is alternatively fed with the raw gas and with the gas having
passed the converter that reduces NO to NO. Therefore, NO and NO are determined alternately.
2 x
Chemiluminescence analysers are combined with an extractive sampling system and a gas conditioning
system. A sample of gas is taken from the stack with a sampling probe and conveyed to the analyser through
a sampling line and suitable gas conditioning system. The values from the analyser are recorded and/or
stored by means of electronic data processing.
Interference due to CO in the sample gas is possible, particularly in the presence of water vapour, due to
2
quenching of the chemiluminescence. The extent of the quenching depends on the CO and H O
2 2
concentrations and the type of analyser used. Any necessary corrections may be made to the analyser output
to increase its accuracy for example by reference to correction curves supplied by the manufacturers or by
calibrating with gases containing approximately the same concentration of CO as the sample gas.
2
NOTE 1 A vacuum chemiluminescent-NO analyser reduces the CO and H O quenching error.
2 2
x
3
NOTE 2 A correction of the NO concentration may be necessary if the NH concentration is higher than 20 mg/m .
3
x
In flue gases from conventional combustion systems the nitrogen oxides consist of more than 95 % NO. The
remaining oxide is predominantly NO . These two oxides (NO + NO ) are designated as NO .
2 2 x
It should be noted, that in other processes, the ratio of NO to NO may be different and other nitrogen oxides
x
may be present.
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5 Description of measuring equipment
5.1 General on sampling and sample gas conditioning systems
A volume of flue gas (see 8.2) is extracted from the emission source for a fixed period of time at a controlled
flow rate. The sampling system consists of:
a sampling probe;
a filter;
a sampling line;
a conditioning system.
A filter removes the dust in the sampled volume before the sample is conditioned and passed to the analyser.
Four different sampling and conditioning configurations are available in order to avoid uncontrolled water
condensation in the measuring system (see also Annex A). Each of the first three configurations requires that
the user shall check that the dew point temperature is lower or equal to 4 °C at the outlet of the analyser. The
user may correct the results for the remaining water content in order to report results on a dry basis (refer to
the table of Annex B in prEN 14790).
These configurations are:
Configuration 1: removal of water vapour by condensation using a cooling system;
Configuration 2: removal of water vapour through elimination within a permeation drier;
Configuration 3: dilution with dry, clean ambient air or nitrogen of the gas to be characterised;
Configuration 4: maintaining the temperature of the sampling line up to the heated analyser.
It is important that all parts of the sampling equipment upstream of the analyser are made of materials that do
not react with or absorb NO . Except for the cooling system of configuration 1, the temperature of the
x
components likely to be in contact with the gas, shall be maintained at a sufficiently high temperature to avoid
any condensation.
Conditions and layout of the sampling equipment contribute to the combined uncertainty of the measurement.
In order to minimise this contribution to the combined measurement uncertainty, performance criteria for the
sampling equipment and sampling conditions are specified in 5.2 and Clause 6.
Some other conditioning systems may exist and could be acceptable, provided they fulfil the requirements of
this European Standard and have been validated with success during the certification process. For example,
some systems put gas in depression using a simple Sonic nozzle in the collection probe in order to create a
partial vacuum (between 50 hPa and 100 hPa absolute) so that the head of collection and the sampling line
does not need to be heated and water vapour condensation is avoided.
In order to minimise losses of NO in the sampling system, the use of configuration 1 shall be avoided when
x
3
the NO concentration represents more than 20 mg/m . Configuration 1 shall be ordinarily avoided when the
2
NO / NO represents more than 25 %, unless it is demonstrated that the losses of NO were not significant
2
2 x
within the gas cooler, at the concentrations of moisture and NO expected in the field. In such cases, the
2
losses of NO in the sampling system shall not exceed 10%.
2
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5.2 Sampling and conditioning system
5.2.1 Sampling probe
In order to reach the measurement points of the measurement plane, probes of different lengths and inner
diameters may be used. The design and configuration of the probe used shall ensure the residence time of
the sample gas within the probe is minimised in order to reduce the response time of the measuring system.
NOTE 1 The probe can be marked before sampling in order to demonstrate that the measurement points in the
measurement plane have been reached.
NOTE 2 A sealable connection can be installed on the probe in order to introduce test gases for adjustment.
5.2.2 Filter
The filter and filter holder shall be made of an inert material (e.g. ceramic or sinter metal filter with an
appropriate pore size). It shall be heated above the water or acid dew point. The particle filter shall be
changed or cleaned periodically depending on the dust loading at the measuring site.
NOTE Overloading of the particle filter may cause loss of nitrogen dioxide by sorption onto the particulate matter and
may also increase the pressure drop in the sampling line.
5.2.3 Sampling line
The sampling line shall be heated up to the conditioning system. It shall be made of a suitable corrosion
resistant material (e.g. stainless steel, borosilicate glass, ceramic; PTFE is only suitable for flue-gas
temperature lower than 200 °C). At temperatures greater than 250 °C, stainless steel and certain other
materials can alter the ratio of NO /NO . In this case, ceramic, glass, quartz or titanium should be used.
x
2
Excessive temperatures should be avoided because this might alter the flue gas characteristics.
5.2.4 Conditioning system
5.2.4.1 Sample cooler (configuration 1)
The design of the sample gas cooler shall be such that absorption of NO in the condensates is minimised.
2
Because overpressure in the cooling system increases losses of NO in the condensates, the pump shall be
2
situated between the cooling system and the analyser. In the case that the concentration of NO in the sample
2
gas becomes too high, the use of a gas cooler can produce errors on the NO measurement. This can occur
2
because of the solubility of NO in the condensed water and shall also depend on the content of water vapour
2
in the flue gas. A maximum dew-point temperature of 4 °C shall not be exceeded at the outlet of the sample
cooler.
In order to minimise losses of NO in the sampling system, the use of configuration 1 shall
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