EN 14790:2017
(Main)Stationary source emissions - Determination of the water vapour in ducts - Standard reference method
Stationary source emissions - Determination of the water vapour in ducts - Standard reference method
This European Standard specifies the standard reference method (SRM) based on a sampling system with a condensation/adsorption technique to determine the water vapour concentration in the flue gases emitted to atmosphere from ducts and stacks.
This European Standard specifies the performance characteristics to be determined and performance criteria to be fulfilled by measuring systems based on the measurement method. It applies to periodic monitoring and to 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 prEN 14793.
This European Standard is applicable in the range of water vapour content from 4 % to 40 % as volume concentrations and of water vapour mass concentration from 29 g/m3 to 250 g/m3 as a wet gas, although for a given temperature the upper limit of the method is related to the maximum pressure of water in air or in the gas.
In this European Standard all the concentrations are expressed at standard conditions (273 K and 101,3 kPa).
NOTE 1 For saturated conditions the condensation/adsorption method is not applicable. Some guidance is given in this European Standard to deal with flue gas when droplets are present.
This European Standard has been evaluated during field tests on waste incineration, co-incineration and large combustion plants. It has been validated for sampling periods of 30 min in the volume concentration range of 7 % to 26 %.
NOTE 2 The characteristics of installations, the conditions during field tests and the values of repeatability and reproducibility in the field are given in Annex A.
Emissionen aus stationären Quellen - Bestimmung von Wasserdampf in Kanälen - Standardreferenzverfahren
Diese Europäische Norm legt das Standardreferenzverfahren (SRM) auf Basis einer Probenahmeeinrichtung mit einer Kondensations-/Adsorptionstechnik zur Bestimmung der Konzentration von Wasserdampf in Abgasen, die aus Abgaskanälen in die Atmosphäre emittiert werden, fest.
Diese Europäische Norm legt zu bestimmende Verfahrenskenngrößen und Mindestanforderungen fest, die von Messeinrichtungen 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 gilt für einen Bereich des Wasserdampfgehalts von 4 % bis 40 % als Volumenkonzentration und für Wasserdampfkonzentrationen im feuchten Abgas von 29 g/m3 bis 250 g/m3. Die Obergrenze des Verfahrens hängt bei einer vorgegebenen Temperatur vom maximalen Wasserdampfdruck in Luft oder Gas ab.
In dieser Europäischen Norm werden alle Konzentrationen auf Normbedingungen bezogen (273 K und 101,3 kPa).
ANMERKUNG 1 Das Kondensations-/Adsorptions-Verfahren ist nicht für den gesättigten Zustand anwendbar. Einige Hinweise in dieser Europäischen Norm behandeln den Umgang mit Abgasen in Gegenwart von Tröpfchen.
Diese Europäische Norm wurde in Feldversuchen an Abfallverbrennungsanlagen, Mitverbrennungsanlagen und Großfeuerungsanlagen mit Probenahmedauern von 30 min für Volumenkonzentrationen von 7 % bis 26 % validiert.
ANMERKUNG 2 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 vapeur d'eau dans les conduits - Méthode de référence normalisée
La présente Norme européenne spécifie la méthode de référence normalisée (SRM) basée sur un système de prélèvement associé à une technique de condensation/adsorption, pour déterminer la concentration en vapeur d'eau des effluents gazeux émis dans l'atmosphère par les conduits et cheminées.
La présente Norme européenne spécifie les caractéristiques de performance 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, Automated 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 d'une méthode « alternative » à la méthode de référence normalisée par l'application du prEN 14793.
La présente Norme européenne s'applique dans la gamme de teneur en vapeur d'eau comprise entre 4 % et 40 % en concentrations volumiques et dans la gamme de concentration massique en vapeur d'eau comprise entre 29 g/m3 et 250 g/m3 sous forme de gaz humide, bien qu'à une température donnée, la limite supérieure de la méthode soit liée à la pression maximale de l'eau dans l'air ou le gaz.
Dans la présente Norme européenne, toutes les concentrations sont exprimées dans des conditions normales (273 K et 101,3 kPa).
NOTE 1 La méthode de condensation/d'adsorption ne s'applique pas dans des conditions saturées. La présente Norme européenne fournit des lignes directrices pour le traitement des effluents gazeux en présence de vésicules.
La présente Norme européenne a été évaluée au cours d'essais sur site pratiqués sur des installations destinées à l'incinération et à la coincinération des déchets ainsi que sur de grandes installations de combustion. Elle a été validée pour des périodes de prélèvement de 30 min, dans une gamme de concentration volumique de 7 % à 26 %.
NOTE 2 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 A.
Emisije nepremičnih virov - Določevanje vodne pare v odvodnikih - Standardna referenčna metoda
Ta evropski standard določa standardno referenčno metodo (SRM) na podlagi sistema vzorčenja s tehniko kondenzacije/absorpcije za določanje koncentracije vodne pare v dimnih plinih, ki prehajajo v ozračje iz vodov in odvodnikov.
Ta evropski standard določa lastnosti zmogljivosti in merila zmogljivosti, ki jih morajo izpolnjevati merilni sistemi na podlagi te merilne metode. Uporablja se za redno spremljanje in umerjanje 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 se uporablja v območju vsebnosti vodne pare 4–40 % kot prostorninskih koncentracij in koncentracije mase vodne pare 29–250 g/m3 kot vlažnega plina, čeprav je pri določeni temperaturi zgornja meja metode povezana z največjim tlakom vode v zraku ali v plinu.
V tem evropskem standardu so vse koncentracije izražene pri standardnih pogojih (273 K in 101,3 kPa).
OPOMBA 1:Metoda kondenzacije/absorpcije se ne uporablja pri nasičenih pogojih. V tem evropskem standardu je podanih nekaj smernic za obravnavanje dimnega plina, kadar so prisotne kapljice.
Ta evropski standard je bil ocenjen med preskusi sežiganja odpadkov, sosežiga in velikih kurilnih naprav na terenu. Potrjen je bil za 30-minutna obdobja vzorčenja v razponu prostorninske koncentracije 7–26 %.
OPOMBA 2:Lastnosti naprav, pogoji med preskusi na terenu ter vrednosti ponovljivosti in reprodukcije na terenu so podani v dodatku A.
General Information
RELATIONS
Standards Content (sample)
SLOVENSKI STANDARD
SIST EN 14790:2017
01-julij-2017
1DGRPHãþD
SIST EN 14790:2005
(PLVLMHQHSUHPLþQLKYLURY'RORþHYDQMHYRGQHSDUHYRGYRGQLNLK6WDQGDUGQD
UHIHUHQþQDPHWRGD
Stationary source emissions - Determination of the water vapour in ducts - Standard
reference methodEmissionen aus stationären Quellen - Bestimmung von Wasserdampf in Leitungen -
Standardreferenzverfahren
Emissions de sources fixes - Détermination de la vapeur d'eau dans les conduits -
Méthode de référence normaliséeTa slovenski standard je istoveten z: EN 14790:2017
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
SIST EN 14790:2017 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------SIST EN 14790:2017
---------------------- Page: 2 ----------------------
SIST EN 14790:2017
EN 14790
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2017
EUROPÄISCHE NORM
ICS 13.040.40 Supersedes EN 14790:2005
English Version
Stationary source emissions - Determination of the water
vapour in ducts - Standard reference method
Emissions de sources fixes - Détermination de la Emissionen aus stationären Quellen - Bestimmung von
vapeur d'eau dans les conduits - Méthode de référence Wasserdampf in Kanälen - Standardreferenzverfahren
normaliséeThis European Standard was approved by CEN on 26 September 2016.
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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14790:2017 E
worldwide for CEN national Members.---------------------- Page: 3 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
Contents Page
European foreword ....................................................................................................................................................... 4
1 Scope .................................................................................................................................................................... 5
2 Normative references .................................................................................................................................... 5
3 Terms and definitions ................................................................................................................................... 6
4 Symbols and abbreviations ...................................................................................................................... 11
4.1 Symbols ............................................................................................................................................................ 11
4.2 Abbreviated terms ....................................................................................................................................... 12
5 Principle .......................................................................................................................................................... 12
5.1 General ............................................................................................................................................................. 12
5.2 Adsorption or condensation/adsorption method ............................................................................ 12
5.3 Temperature method ................................................................................................................................. 12
6 Description of the measuring system ................................................................................................... 13
6.1 General ............................................................................................................................................................. 13
6.2 Sampling probe ............................................................................................................................................. 13
6.3 Filter housing ................................................................................................................................................. 13
6.4 Particle filter .................................................................................................................................................. 14
6.5 Trapping system ........................................................................................................................................... 14
6.6 Cooling system (optional) ......................................................................................................................... 14
6.7 Sample gas pump .......................................................................................................................................... 14
6.8 Gas volume meter ........................................................................................................................................ 14
6.9 Barometer ....................................................................................................................................................... 15
6.10 Balance ............................................................................................................................................................. 15
6.11 Temperature measurement ..................................................................................................................... 15
7 Performance characteristics of the SRM .............................................................................................. 15
8 Field operation .............................................................................................................................................. 16
8.1 Measurement planning .............................................................................................................................. 16
8.2 Sampling strategy......................................................................................................................................... 17
8.2.1 General ............................................................................................................................................................. 17
8.2.2 Measurement section and measurement plane ................................................................................ 17
8.2.3 Minimum number and location of measurement points ............................................................... 17
8.2.4 Measurement ports and working platform ........................................................................................ 17
8.3 Assembling the equipment ....................................................................................................................... 17
8.4 Leak test........................................................................................................................................................... 18
8.5 Performing sampling .................................................................................................................................. 18
8.5.1 Introduction of the sampling probe in the duct ................................................................................ 18
8.5.2 Sampling .......................................................................................................................................................... 18
8.6 Repeatability of the weighing .................................................................................................................. 19
8.7 Procedure for gas streams saturated with water (droplets present) ....................................... 19
9 Water vapour determination ................................................................................................................... 19
10 Equivalence of an alternative method .................................................................................................. 21
11 Measurement report ................................................................................................................................... 21
---------------------- Page: 4 ----------------------SIST EN 14790:2017
EN 14790:2017 (E)
Annex A (informative) Validation of the method in the field ..................................................................... 22
A.1 General ............................................................................................................................................................. 22
A.2 Characteristics of installations ................................................................................................................ 22
A.3 Repeatability and reproducibility in the field .................................................................................... 23
A.3.1 General ............................................................................................................................................................. 23
A.3.2 Repeatability .................................................................................................................................................. 24
A.3.3 Reproducibility .............................................................................................................................................. 25
Annex B (normative) Determination of water vapour concentration for water saturated
gas, at p = 101,325 kPa ............................................................................................................................ 26
refAnnex C (informative) Type of sampling equipment .................................................................................... 30
Annex D (informative) Example of assessment of compliance of standard reference method
for water vapour with given uncertainty requirements ................................................................ 31
D.1 General ............................................................................................................................................................. 31
D.2 Elements required for the uncertainty determinations ................................................................. 31
D.3 Example of an uncertainty calculation.................................................................................................. 31
D.3.1 Specific conditions in the field ................................................................................................................. 31
D.3.2 Performance characteristics .................................................................................................................... 32
D.3.3 Model equation and application of the rule of the uncertainty propagation ......................... 34
D.3.3.1 Water vapour content ................................................................................................................................. 34
D.3.3.2 Effect of the collection efficiency ............................................................................................................. 35
D.3.3.3 Calculation of the combined uncertainty of the water vapour content taking into
account the collection efficiency ............................................................................................................. 35
D.3.3.4 Calculation of sensitivity coefficients .................................................................................................... 36
D.3.3.5 Calculation of the standard uncertainty of the collection efficiency ......................................... 36
D.3.3.6 Calculation of the standard uncertainty of measured dry gas volume corrected to
standard conditions ..................................................................................................................................... 37
D.3.3.7 Calculation of the combined uncertainty of the water vapour content .................................... 38
D.3.3.8 Results of standard uncertainties calculations.................................................................................. 38
D.3.4 Estimation of the combined uncertainty .............................................................................................. 41
Annex E (informative) Significant technical changes ................................................................................... 42
Bibliography ................................................................................................................................................................. 43
---------------------- Page: 5 ----------------------SIST EN 14790:2017
EN 14790:2017 (E)
European foreword
This document (EN 14790:2017) has been prepared by Technical Committee CEN/TC 264 “Air quality”,
the secretariat of which is held by DIN.This document supersedes EN 14790:2005.
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 E 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.---------------------- Page: 6 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
1 Scope
This European Standard specifies the standard reference method (SRM) based on a sampling system
with a condensation/adsorption technique to determine the water vapour concentration in the flue
gases emitted to atmosphere from ducts and stacks.This European Standard specifies the performance characteristics to be determined and performance
criteria to be fulfilled by measuring systems based on the measurement method. It applies to periodic
monitoring and to 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 is applicable in the range of water vapour content from 4 % to 40 % as volume
3 3concentrations and of water vapour mass concentration from 29 g/m to 250 g/m as a wet gas,
although for a given temperature the upper limit of the method is related to the maximum pressure of
water in air or in the gas.In this European Standard all the concentrations are expressed at standard conditions (273 K and
101,3 kPa).NOTE 1 For saturated conditions the condensation/adsorption method is not applicable. Some guidance is
given in this European Standard to deal with flue gas when droplets are present.This European Standard has been validated during field tests on waste incineration, co-incineration and
large combustion plants. It has been validated for sampling periods of 30 min in the volume
concentration range of 7 % to 26 %.NOTE 2 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 1911, Stationary source emissions - Determination of mass concentration of gaseous chlorides
expressed as HCl - Standard reference methodEN 14791:2017, Stationary source emissions — Determination of mass concentration of sulphur oxides —
Standard reference methodEN 14793:2017, Stationary source emission – Demonstration of equivalence of an alternative method with
a reference methodEN 15259:2007, Air quality - Measurement of stationary source emissions - Requirements for
measurement sections and sites and for the measurement objective, plan and report
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty
in measurement (GUM:1995)---------------------- Page: 7 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
standard reference method
SRM
reference method prescribed by European or national legislation
[SOURCE: EN 15259:2007]
3.2
reference method
measurement method taken as a reference by convention, which gives the accepted reference value of
the measurandNote 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, other requirements and measurement report[SOURCE: EN 14793:2017]
3.4
alternative method
measurement method which complies with the criteria given by this European Standard with respect to
the reference methodNote 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]
---------------------- Page: 8 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
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
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 referenceNote 1 to entry: In case of automated measuring systems (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: In case of manual methods the applicable reference can be reference materials used as
calibration standards to establish the relationship between the output signal of the analytical device and the
reference values.Note 3 to entry: Calibration should not be confused with adjustment of a measuring system.
3.8measurand
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.3.9
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]
3.10
measurement plane
plane normal to the centre line of the duct at the sampling position
Note 1 to entry: Measurement plane is also known as sampling plane.
[SOURCE: EN 15259:2007]
---------------------- Page: 9 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
3.11
measurement port
opening in the waste gas duct along the measurement line, through which access to the waste gas is
gainedNote 1 to entry: Measurement port is also known as sampling port or access port.
[SOURCE: EN 15259:2007]
3.12
measurement line
line in the measurement plane along which the measurement points are located, bounded by the inner
duct wallNote 1 to entry: Measurement line is also known as sampling line.
[SOURCE: EN 15259:2007]
3.13
measurement point
position in the measurement plane at which the sample stream is extracted or the measurement data
are obtained directlyNote 1 to entry: Measurement point is also known as sampling point.
[SOURCE: EN 15259:2007]
3.14
absorber
device in which water vapour is absorbed
3.15
droplets
small liquid particles of condensed water vapour or water liquid in the flue gas (e.g. coming from a
scrubber)Note 1 to entry: In adiabatic equilibrium conditions, droplets could arise only if a gas stream is saturated with
water.3.16
dew point
temperature below which the condensation of water vapour begins at the given pressure condition of
the flue gas3.17
vapour pressure
pressure of water in vapour form
3.18
performance characteristic
one of the quantities (described by values, tolerances, range) assigned to equipment in order to define
its performance---------------------- Page: 10 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
3.19
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 measurementNote 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 can 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 %.3.20
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 measurementNote 1 to entry: These conditions include:
— same measurement method;
— two sets of equipment, the performances of which are fulfilling 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 can 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 %.---------------------- Page: 11 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
3.21
reproducibility in the field
closeness of the agreement between the results of simultaneous measurements of the same measurand
carried out with several sets of equipment under the same conditions of measurement
Note 1 to entry: These conditions include:— same measurement method;
— several sets of equipment, the performances of which are fulfilling the requirements of the
measurement method, used under the same conditions;— same location;
— implemented by several laboratories.
Note 2 to entry: Reproducibility can 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 %.3.22
uncertainty
parameter associated with the result of a measurement, that characterises the dispersion of the values
that could reasonably be attributed to the measurand3.23
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation
3.24
combined uncertainty
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)3.25
expanded uncertainty
quantity defining a level of confidence about the result of a measurement that may be expected to
encompass a specific fraction of the distribution of values that could reasonably be attributed to a
measurandU ku×
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.
3.26uncertainty 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
---------------------- Page: 12 ----------------------SIST EN 14790:2017
EN 14790:2017 (E)
4 Symbols and abbreviations
4.1 Symbols
For the purposes of this document, the following symbols apply.
C measured volume concentration
C water vapour mass concentration on dry basis
h measured water vapour content on wet basis expressed as volume
concentration
k coverage factor
m mass of water vapour trapped in the trapping system
Mw molecular weight of water, 18,01534 g/mol rounded to 18 g/mol
p absolute pressure at the gas volume meter
p (T ) saturation vapour pressure of water at the temperature T of the gas
s m m
volume meter
p standard pressure, 101,3 kPa
ref
s reproducibility standard deviation
s maximum allowable repeatability standard deviation
r,limit
T ith temperature reading
T mean absolute temperature of the sampled gas at the gas volume meter
T standard temperature, 273 K
ref
u standard uncertainty
u combined uncertainty
U expanded uncertainty
V gas volume reading from the gas volume meter at the beginning of the
sampling period, at actual conditions of temperature, pressure and
humidity
V2 gas volume reading from the gas volume meter at the end of the sampling
period, at actual conditions of temperature, pressure and humidity
V difference between the readings at the gas volume meter at the beginning
and at the end of the sampling period
V measured dry gas volume, corrected to standard conditions
m,ref
V molar volume at standard conditions, in m /mol at p and T
mol
ref ref
---------------------- Page: 13 ----------------------
SIST EN 14790:2017
EN 14790:2017 (E)
4.2 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
AM alternative method
AMS automated measuring system
PTFE Polytetrafluoroethene
SRM standard reference method
5 Principle
5.1 General
This European Standard describes the standard reference method (SRM) for determining the water-
vapour content emitted to atmosphere from ducts and stacks. The specific components and the
requirements for the measuring system are described in Clause 6. A number of performance
characteristics, together with associated performance criteria are specified for the measurement
method (see Table 1 in Clause 7). The expanded uncertainty of the method shall meet the specifications
given in this European St...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.