Stationary source emissions - Determination of the mass concentration of ammonia - Manual method (ISO 21877:2019)

This document specifies a manual method of measurement including sampling and different analytical methods for the determination of the mass concentration of ammonia (NH3) in the waste gas of industrial plants, for example combustion plants or agricultural plants. All compounds which are volatile at the sampling temperature and produce ammonium ions upon dissociation during sampling in the absorption solution are measured by this method, which gives the volatile ammonia content of the waste gas.
This document specifies an independent method of measurement, which has been validated in field tests in a NH3 concentration range of approximately 8 mg/m3 to 65 mg/m3 at standard conditions. The lower limit of the validation range was determined under operational conditions of a test plant. The measurement method can be used at lower values depending, for example, on the sampling duration, sampling volume and the limit of detection of the analytical method used.
NOTE 1    The plant, the conditions during field tests and the performance characteristics obtained in the field are given in Annex A.
This method of measurement can be used for intermittent monitoring of ammonia emissions as well as for the calibration and validation of permanently installed automated ammonia measuring systems.
NOTE 2    An independent method of measurement is called standard reference method (SRM) in EN 14181.

Emissionen aus stationären Quellen - Ermittlung der Massenkonzentration von Ammoniak - Manuelles Verfahren (ISO 21877:2019)

Dieses Dokument legt ein manuelles Messverfahren einschließlich der Probenahme und verschiedener Analyseverfahren zur Bestimmung der Massenkonzentration von Ammoniak (NH3) im Abgas von Industrieanlagen wie etwa Verbrennungsanlagen oder landwirtschaftlichen Anlagen fest. Alle Stoffe, die bei der Probenahmetemperatur flüchtig sind und bei der Zersetzung während der Probenahme in der Absorptionslösung Ammoniumionen bilden, werden mit diesem Verfahren gemessen, das daher den flüchtigen Ammoniakgehalt im Abgas bestimmt.
Dieses Dokument legt ein unabhängiges Messverfahren fest, das in Feldversuchen einem NH3 Konzentrationsbereich von ungefähr 8 mg/m3 bis 65 mg/m3 unter Normbedingungen validiert wurde. Die untere Grenze des Validierungsbereichs wurde durch die Betriebsbedingungen der untersuchten Anlage bestimmt. Das Messverfahren kann auch bei geringeren Werten in Abhängigkeit beispielsweise von der Probenahmedauer, des Probenvolumens und der Nachweisgrenze des Analyseverfahrens eingesetzt werden.
ANMERKUNG 1   Die Anlage, die Bedingungen der Feldversuche und die im Rahmen der Feldversuche ermittelten Verfahrenskenngrößen sind in Anhang A angegeben.
Dieses Messverfahren kann für die wiederkehrende Überwachung von Ammoniak-Emissionen sowie die Kalibrierung und Validierung dauerhaft eingebauter automatischer Ammoniak-Messeinrichtungen verwendet werden.
ANMERKUNG 2   Ein unabhängiges Messverfahren wird in EN 14181 als Standardreferenzverfahren (SRM, en: standard reference method) bezeichnet.

Émissions de sources fixes - Détermination de la concentration en masse de l’ammoniac dans les gaz de combustion - Méthode manuelle (ISO 21877:2019)

Le présent document spécifie une méthode manuelle de mesurage comprenant l'échantillonnage ainsi que différentes méthodes d'analyse pour la détermination de la concentration en masse de l'ammoniac (NH3) dans les effluents gazeux des installations industrielles, par exemple les installations de combustion ou les exploitations agricoles. Tous les composés volatils à la température d'échantillonnage et produisant des ions ammonium dans la solution d'absorption durant l'échantillonnage sont mesurés par cette méthode qui donne alors la teneur en ammoniac volatil des effluents gazeux.
Le présent document spécifie une méthode de mesure indépendante qui a été validée lors d'essais sur site dans une gamme de concentration en NH3 d'environ 8 mg/m3 à 65 mg/m3 dans des conditions normales. La limite inférieure de la gamme de validation a été déterminée dans les conditions opérationnelles d'une installation d'essai. La méthode de mesure peut être utilisée à des valeurs moins élevées, en fonction, par exemple, de la durée d'échantillonnage, du volume d'échantillonnage et de la limite de détection de la méthode d'analyse utilisée.
NOTE 1    L'installation, les conditions des essais sur site et les caractéristiques de performance obtenues sur le site sont indiquées à l'Annexe A.
Cette méthode de mesure peut être utilisée pour la surveillance intermittente des émissions d'ammoniac ainsi que pour l'étalonnage et la validation de systèmes de mesurage automatisés des concentrations en ammoniac.
NOTE 2    Une méthode de mesure indépendante est appelée « méthode de référence normalisée » (SRM) dans l'EN 14181.

Emisije nepremičnih virov - Določevanje masne koncentracije amoniaka - Ročna metoda (ISO 21877:2019)

Ta dokument določa ročno metodo merjenja, vključno z vzorčenjem in različnimi analitičnimi metodami, za določanje masne koncentracije amoniaka (NH3) v odpadnih plinih industrijskih obratov, na primer kurilnih naprav ali kmetijskih obratov. Po tej metodi se merijo vse spojine, ki so hlapne pri temperaturi vzorčenja in tvorijo amonijeve ione po razpadu v absorpcijski raztopini, kar daje vsebnost hlapnega amoniaka v odpadnih plinih. Ta dokument določa neodvisno metodo merjenja, ki je bila potrjena v terenskih preskusih do koncentracije NH3 približno 65 mg/m3 pri standardnih pogojih. To metodo merjenja je mogoče uporabljati za občasno spremljanje emisij amoniaka, pa tudi za umerjanje in potrjevanje stalno nameščenih avtomatiziranih merilnih sistemov za amoniak.

General Information

Status
Published
Publication Date
08-Oct-2019
Technical Committee
Drafting Committee
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
09-Oct-2019
Completion Date
09-Oct-2019

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SLOVENSKI STANDARD
SIST EN ISO 21877:2019
01-december-2019
Emisije nepremičnih virov - Določevanje masne koncentracije amoniaka - Ročna
metoda (ISO 21877:2019)

Stationary source emissions - Determination of the mass concentration of ammonia -

Manual method (ISO 21877:2019)
Emissionen aus stationären Quellen - Ermittlung der Massenkonzentration von
Ammoniak - Manuelles Verfahren (ISO 21877:2019)

Émissions de sources fixes - Détermination de la concentration en masse de l’ammoniac

dans les gaz de combustion - Méthode manuelle (ISO 21877:2019)
Ta slovenski standard je istoveten z: EN ISO 21877:2019
ICS:
13.040.40 Emisije nepremičnih virov Stationary source emissions
SIST EN ISO 21877:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 21877:2019
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SIST EN ISO 21877:2019
EN ISO 21877
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 13.040.40
English Version
Stationary source emissions - Determination of the mass
concentration of ammonia - Manual method (ISO
21877:2019)

Émissions de sources fixes - Détermination de la Emissionen aus stationären Quellen - Ermittlung der

concentration en masse de l'ammoniac dans les gaz de Massenkonzentration von Ammoniak - Manuelles

combustion - Méthode manuelle (ISO 21877:2019) Verfahren (ISO 21877:2019)
This European Standard was approved by CEN on 26 July 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21877:2019 E

worldwide for CEN national Members.
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SIST EN ISO 21877:2019
EN ISO 21877:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 21877:2019
EN ISO 21877:2019 (E)
European foreword

This document (EN ISO 21877:2019) has been prepared by Technical Committee ISO/TC 146 "Air

quality" in collaboration with 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 April 2020, and conflicting national standards shall be

withdrawn at the latest by April 2020.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

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, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 21877:2019 has been approved by CEN as EN ISO 21877:2019 without any modification.

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SIST EN ISO 21877:2019
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SIST EN ISO 21877:2019
INTERNATIONAL ISO
STANDARD 21877
First edition
2019-08
Stationary source emissions —
Determination of the mass
concentration of ammonia — Manual
method
Émissions de sources fixes — Détermination de la concentration en
masse de l’ammoniac — Méthode manuelle
Reference number
ISO 21877:2019(E)
ISO 2019
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols and abbreviated terms ........................................................................................................................................................... 3

5 Principle of the method of measurement ................................................................................................................................... 5

6 Sampling system ................................................................................................................................................................................................... 6

6.1 General ........................................................................................................................................................................................................... 6

6.2 Sampling equipment .......................................................................................................................................................................... 6

6.2.1 Non-isokinetic sampling ........................................................................................................................................... 6

6.2.2 Isokinetic sampling ........................................................................................................................................... ............. 7

6.3 Other equipment ................................................................................................................................................................................... 9

7 Performance characteristics .................................................................................................................................................................... 9

7.1 General ........................................................................................................................................................................................................... 9

7.2 Performance characteristics of the sampling system ............................................................................................ 9

7.3 Performance characteristics of the analysis ...............................................................................................................10

7.3.1 Sources of uncertainty .............................................................................................................................................10

7.3.2 Performance criterion of analysis ..................................................................................................................10

7.4 Establishment of the uncertainty budget .....................................................................................................................11

8 Field operation ....................................................................................................................................................................................................11

8.1 Measurement planning .................................................................................................................................................................11

8.2 Sampling strategy ..............................................................................................................................................................................11

8.3 Field blank ...............................................................................................................................................................................................12

8.4 Leak test .....................................................................................................................................................................................................12

8.5 Sampling ....................................................................................................................................................................................................13

8.6 Sample transport and storage .................................................................................................................................................13

9 Analytical determination ..........................................................................................................................................................................13

10 Calculation of the results ..........................................................................................................................................................................14

11 Measurement report .....................................................................................................................................................................................15

Annex A (informative) Validation of the method of measurement in the field .....................................................16

Annex B (informative) Description of the analytical method — Spectrophotometry ....................................21

Annex C (informative) Description of the analytical method — Continuous flow analysis (CFA) ......25

Annex D (informative) Description of the analytical method — Ion chromatography .................................28

Annex E (informative) Example of the calculation of the uncertainty budget .......................................................32

Annex F (informative) Calculation of the uncertainty associated with a mass concentration

expressed on dry gas and at an oxygen reference concentration ...................................................................40

Bibliography .............................................................................................................................................................................................................................44

© ISO 2019 – All rights reserved iii
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso

.org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,

Stationary source emissions.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
Introduction

Ammonia emissions arise to a large extent from agriculture. Industries such as chemical production

processes (e.g. fertilizer production plants) emit ammonia as well as power plants, cement factories and

waste incineration plants with SCR and non-SCR reactors with ammonia slip. The ammonia emissions

are measured and often controlled by legislation.

This document specifies an independent method of measurement for intermittent monitoring of

ammonia emissions as well as for the calibration and validation of automated ammonia measuring

systems.

This document can be used in conjunction with ISO 17179 which specifies performance characteristics

of automated measuring systems (AMS) for the determination of the mass concentration of ammonia in

waste gas. According to ISO 17179, permanently installed AMS for continuous monitoring of ammonia

emissions are calibrated and validated by comparison with an independent method of measurement.

The uncertainty of measured values obtained by permanently installed AMS for continuous monitoring

are determined by comparison measurements with an independent method of measurement as

part of the calibration and validation of the AMS. This ensures that the measurement uncertainty is

representative of the emission at a specific plant.
© ISO 2019 – All rights reserved v
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SIST EN ISO 21877:2019
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SIST EN ISO 21877:2019
INTERNATIONAL STANDARD ISO 21877:2019(E)
Stationary source emissions — Determination of the mass
concentration of ammonia — Manual method
1 Scope

This document specifies a manual method of measurement including sampling and different analytical

methods for the determination of the mass concentration of ammonia (NH ) in the waste gas of

industrial plants, for example combustion plants or agricultural plants. All compounds which are

volatile at the sampling temperature and produce ammonium ions upon dissociation during sampling

in the absorption solution are measured by this method, which gives the volatile ammonia content of

the waste gas.

This document specifies an independent method of measurement, which has been validated in field

3 3

tests in a NH concentration range of approximately 8 mg/m to 65 mg/m at standard conditions. The

lower limit of the validation range was determined under operational conditions of a test plant. The

measurement method can be used at lower values depending, for example, on the sampling duration,

sampling volume and the limit of detection of the analytical method used.

NOTE 1 The plant, the conditions during field tests and the performance characteristics obtained in the field

are given in Annex A.

This method of measurement can be used for intermittent monitoring of ammonia emissions as well

as for the calibration and validation of permanently installed automated ammonia measuring systems.

NOTE 2 An independent method of measurement is called standard reference method (SRM) in EN 14181.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 7150-1, Water quality — Determination of ammonium — Part 1: Manual spectrometric method

ISO 11732, Water quality — Determination of ammonium nitrogen — Method by flow analysis (CFA and

FIA) and spectrometric detection
+ + + + 2+ 2+ 2+ 2+ 2+

ISO 14911, Water quality — Determination of dissolved Li , Na , NH , K , Mn , Ca , Mg , Sr and Ba

using ion chromatography — Method for water and waste water

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.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
© ISO 2019 – All rights reserved 1
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
3.1
mass concentration

mass of a substance in an emitted waste gas divided by the volume of the emitted waste gas

Note 1 to entry: Mass concentration is often expressed as milligrams per cubic metre (mg/m ).

3.2
measurement site

place on the waste gas duct in the area of the measurement plane(s) (3.3) consisting of structures and

technical equipment, for example working platforms, measurement ports (3.4), energy supply

Note 1 to entry: Measurement site is also known as sampling site.
3.3
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.
3.4
measurement port

opening in the waste gas duct along the measurement line (3.5), through which access to the waste gas

is gained
Note 1 to entry: Measurement port is also known as sampling port or access port.
3.5
measurement line

line in the measurement plane (3.3) along which the measurement points (3.6) are located, bounded by

the inner duct wall
Note 1 to entry: Measurement line is also known as sampling line.
3.6
measurement point

position in the measurement plane (3.3) 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.
3.7
isokinetic sampling

sampling at a rate such that the velocity and direction of the gas entering the sampling nozzle is the

same as that of the gas in the duct at the measurement point (3.6)
3.8
field blank
test sample obtained according to the field blank procedure
3.9
field blank value

result of a measurement performed according to the field blank procedure at the plant site and in the

laboratory
3.10
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
2 © ISO 2019 – All rights reserved
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
3.11
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation
3.12
combined uncertainty

standard uncertainty (3.11) 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)

3.13
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

measurand
Uk=×u

Note 1 to entry: The value of the coverage factor k depends on the number of degrees of freedom and the level of

confidence. In this document a level of confidence of 95 % is used.

Note 2 to entry: The expression overall uncertainty is sometimes used to express the expanded uncertainty.

3.14
uncertainty budget

calculation table combining all the sources of uncertainty according to ISO 14956 or ISO/IEC Guide 98-3

in order to calculate the combined uncertainty of the method at a specified value

4 Symbols and abbreviated terms
For the purposes of this document, the following symbols apply.
a intercept of the calibration function
A peak area
b slope of the calibration function
c second order slope of the calibration function
c NH mass concentration at standard conditions
m 3
c NH mass concentration corrected to oxygen reference volume concentration
corr 3
c mass concentration expressed on dry basis
dry
c mass concentration expressed on wet basis
wet
E absorbance at wavelength λ

instrument specific factor for converting the result determined for NH into a result for

NH and the unit mg/ml
factor for converting NH to NH ( f = 0,944)
4 3 N
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
h volume fraction of the water vapour in the sample gas
k coverage factor
k coverage factor for a coverage probability of 95 %
0,95
m NH mass in the sample
s 3
o measured oxygen volume concentration in the duct
o oxygen reference volume concentration
ref
p atmospheric pressure at the measurement site
atm
p absolute pressure at the gas volume meter
p standard pressure, 101,3 kPa
ref
p relative pressure measured at the gas volume meter
rel
P coverage probability
R peak resolution for the peak pair (2,1)
2,1
t retention time for peak 1
t retention time for peak 2
T temperature of the sample gas at the gas volume meter
T standard temperature, 273 K
ref
u standard uncertainty
u combined uncertainty
u uncertainty contribution due to calibration
cal
u uncertainty contribution due to drift
u uncertainty contribution due to calculation of the mean
mean
u uncertainty contribution due to reading
read
u relative standard uncertainty
rel
u uncertainty contribution due to repeatability standard deviation
rep
u uncertainty contribution due to resolution
res
u uncertainty contribution due to tolerance of the cylinder
tol
U expanded uncertainty
U expanded uncertainty for a coverage probability of 95 %
0,95
U relative expanded uncertainty for a coverage probability of 95 %
rel,0,95
v volume of the sample absorption solution
V measured volume of the sample gas at operating conditions
4 © ISO 2019 – All rights reserved
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SIST EN ISO 21877:2019
ISO 21877:2019(E)
V measured volume of the sample gas at standard conditions
m,ref
w peak width for peak 1
w peak width for peak 2
y measured value in units specific to the instrument
Z dilution factor
NH mass concentration in the calibration solution
β NH
()4
NH mass concentration in the sample absorption solution
β NH
() 4
s 4
λ wavelength
v number of degrees of freedom
For the purposes of this document, the following abbreviated terms apply.
AMS automated measuring system
DM water demineralised water
PE polyethylene
PP polypropylene
SRM standard reference method
5 Principle of the method of measurement

A representative sample is taken from the waste gas flow of the plant for a specified sampling duration

and a specified sample gas flow. Isokinetic sampling is necessary if the waste gas contains droplets.

The sampling probe is heated to a temperature that ensures evaporation of the droplets and avoids

condensation of water vapour in the sample gas. Particles, which can be separated at this temperature,

are deposited on a specified particle filter. For non-isokinetic sampling, the use of a particle filter inside

the waste gas duct, is preferred since it does not require separate heating. If a particle filter outside

the waste gas duct is used, then heating of the particle filter to a specified temperature is required to

establish representative conditions and to avoid condensation of water vapour in the sample gas.

All compounds which are volatile at the sampling temperature and produce ammonium ions upon

dissociation during sampling in the absorption solution are measured by this method, which therefore

gives the volatile ammonia content of the waste gas.

NOTE 1 In the presence of semi-volatile ammonia salts, the choice of the sampling temperature can have

influence on the gas/solid balance of the volatile ammonia content.

Ammonia (NH ) in the sample gas passing through the filter is collected in an absorption system

acidified with H SO . The mass of NH is determined after sampling by using one of the analytical

2 4 4
methods specified in Clause 9.

NOTE 2 For total ammonia determination, both particulate matter and gas are analysed. Analysis of

particulate matter is not part of this document.

The volume of the sample gas is determined during sampling, for example by using a gas volume meter.

The mass concentration is calculated as the quotient of the ammonia mass collected in the absorption

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SIST EN ISO 21877:2019
ISO 21877:2019(E)

solution in milligrams (mg) and the volume of the sample gas in cubic metres (m ) and expressed as

milligrams per cubic metre (mg/m ) of ammonia (NH ).
6 Sampling system
6.1 General

6.1.1 The sampling system shall allow for the extraction of the sample gas from the waste gas duct. It

consists in principle of:
— sampling probe;
— particle filter;
— absorption unit consisting of two absorbers;
— suction unit.
The sampling system shall meet the following requirements:

— the sampling probe shall be a heated tube with an inlet made of titanium, quartz glass, borosilicate

glass or PTFE;

— the particle filter shall be a quartz fibre plane filter, to be heated if used outside the waste gas duct;

— the absorbers shall be frit wash bottles (frit porosity: D1 or finer) for low flow sampling or impingers

for high flow sampling;

— the suction unit shall be composed of a pump, volume flow controller, gas volume meter with

thermometer and pressure gauge, and, if required, drying tower;

— all components of the sampling system coming in contact with the waste gas shall be made of

corrosion-resistant material.

The sampling system shall be designed such that the residence time of the sample gas between the inlet

of the sampling probe and the two absorbers is minimized.

The heating of the sample gas line down to the absorption unit shall be maintained at least 15 K above

the dew-point of the waste gas to avoid any water vapour condensation.
6.1.2 The following absorption materials are required for sampling:
6.1.2.1 Absorption solution: 0,05 M H SO solution (quality: analytical grade).
2 4

NOTE The concentration can be increased for high NH concentrations to reach the minimum collection

efficiency.
6.1.2.2 Demineralised water (DM water).
6.2 Sampling equipment
6.2.1 Non-isokinetic sampling

Non-isokinetic sampling may be carried out using a heated probe without nozzle. Figure 1 shows an

example of a sampling system for non-isokinetic sampling. The use of a particle
...

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