EN 16429:2021

SLOVENSKI STANDARD
01-maj-2021
Nadomešča:
SIST-TS CEN/TS 16429:2013
Emisije nepremičnih virov - Referenčna metoda za določevanje koncentracije
plinastega vodikovega klorida (HCl) v odpadnih plinih, ki se sproščajo v ozračje iz
industrijskih naprav
Stationary source emissions - Reference method for the determination of the
concentration of gaseous hydrogen chloride (HCl) in waste gases emitted by industrial
installations into the atmosphere
Emissionen aus stationären Quellen - Referenzverfahren zur Bestimmung der
Konzentration von gasförmigem Chlorwasserstoff (HCl) in Abgasen, die von
Industrieanlagen in die Atmosphäre emittiert werden
Émissions de sources fixes - Méthode de référence pour la détermination de la
concentration de chlorure d’hydrogène gazeux (HCl) dans les effluents gazeux émis
dans l’atmosphère par des installations industrielles
Ta slovenski standard je istoveten z: EN 16429:2021
ICS:
13.040.40 Emisije nepremičnih virov Stationary source emissions
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16429
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 13.040.40 Supersedes CEN/TS 16429:2013
English Version
Stationary source emissions - Reference method for the
determination of the concentration of gaseous hydrogen
chloride (HCl) in waste gases emitted by industrial
installations into the atmosphere
Émissions de sources fixes - Méthode de référence Emissionen aus stationären Quellen -
pour la détermination de la concentration de chlorure Referenzverfahren zur Bestimmung der Konzentration
d'hydrogène gazeux (HCl) dans les effluents gazeux von gasförmigem Chlorwasserstoff (HCl) in Abgasen,
émis dans l'atmosphère par des installations die von Industrieanlagen in die Atmosphäre emittiert
industrielles werden
This European Standard was approved by CEN on 1 February 2021.

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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16429:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 11
4.1 General . 11
4.2 Measuring principle . 12
5 Sampling system . 12
5.1 General . 12
5.2 Sampling probe . 12
5.3 Filter . 12
5.4 Sampling line . 13
5.5 Conditioning system . 13
5.5.1 Permeation drier (configuration 1) . 13
5.5.2 Heated line and heated analyser (configuration 2) . 13
5.6 Sample pump . 13
5.7 Secondary filter (optional) . 13
6 Analyser equipment . 14
7 Determination of the characteristics of the method: analyser, sampling and
conditioning line . 14
7.1 General . 14
7.2 Relevant performance characteristics of the method and performance criteria . 14
7.3 Establishment of the uncertainty budget . 14
8 Field operation . 16
8.1 Measurement plan and sampling strategy . 16
8.2 Setting of the analyser on site . 17
8.2.1 General . 17
8.2.2 Preliminary zero and span check, and adjustments . 17
8.2.3 Zero and span checks after measurement . 18
9 Ongoing quality control . 18
9.1 Introduction . 18
9.2 Frequency of checks . 19
10 Expression of results . 19
11 Equivalence of an alternative method . 20
12 Measurement report . 20
Annex A (informative) Example of assessment of compliance of non-dispersive infrared
method for HCl with requirements on emission measurements . 21
Annex B (informative) Example of correction of data from drift effect . 34
Annex C (informative) Validation of the method in the field . 36
Bibliography . 42
European foreword
This document (EN 16429:2021) has been prepared by Technical Committee CEN/TC 264 “Air quality”,
the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2021, and conflicting national standards shall
be withdrawn at the latest by September 2021.
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.
This document supersedes CEN/TS 16429:2013.
List of significant technical changes compared to CEN/TS 16429:2013:
— Clause 6 "Analyser equipment": The description of the analyser equipment has been replaced by the
reference to performance criteria given in EN 15267-4.
— The informative Annex "Examples of schematics of non-dispersive infrared spectrometer" was
deleted.
— The informative Annex "Validation of the method in the field" was added. EN 16429 has been
validated during field tests on a test bench, on a waste incineration plant and a large combustion
plant for HCl concentrations with sampling periods of 30 min in the range of 2,5 mg/m3 to 61 mg/m3.
The characteristics of installations, the conditions during field tests and the values of repeatability
and reproducibility in the field are given in Annex C.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, 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.
Introduction
The European Commission (EC) has charged the European Committee for Standardization (CEN) to
elaborate this new standard (with Mandate M/513 of January 2013). The work was allocated to
CEN/TC 264 “Air quality”/WG 3, who has prepared this document.
This document has been validated during field tests on a test bench, on a waste incineration plant and a
large combustion plant for HCl concentrations with sampling periods of 30 min in the range of 2,5 mg/m
3 3
to 61 mg/m . Directive 2010/75/EU lays down emission values which are expressed in mg/m , on dry
basis at a specified value of 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 C.
1 Scope
This document specifies the standard reference method (SRM) based on an automatic method for
determination of the mass concentration of hydrogen chloride (HCl) in ducts and stacks emitting to the
atmosphere. It describes the sampling and gas conditioning system.
This document specifies the characteristics to be determined and the performance criteria to be fulfilled
by portable automated measuring systems (P-AMS) using the infrared 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.
The infrared measurement method described in this document can be used as a SRM, provided the
expanded uncertainty of the method is less than 20 % relative at the daily Emission Limit Value (ELV), or
3 3
1 mg/m for ELV below 5 mg/m , and the criteria associated to performance characteristics described in
EN 15267-4 for portable automated measuring systems (P-AMS), are fulfilled.
This document specifies criteria for demonstration of equivalence of an alternative method (AM) to the
SRM by application of EN 14793.
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.
EN 14793, Stationary source emissions — 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 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)
CEN/TS 17337, Stationary source emissions — Determination of mass concentration of multiple gaseous
species — Fourier transform infrared spectroscopy
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:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
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]
3.2
alternative method
AM
measurement method which complies with the criteria given by this document 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]
3.3
ambient temperature
temperature of the air around the measuring system
3.4
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]
3.5
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.
3.6
drift
difference between two zero (zero drift) or span readings (span drift) at the beginning and at the end of
a measuring period
3.7
emission limit value
ELV
emission limit value laid out in EU Directives on the basis of a specified period (e.g. 10 min, 30 min, one
hour, one day…)
3.8
influence quantity
quantity that, in a direct measurement, does not affect the quantity that is actually measured, but affects
the relation between the indication and the measurement result
EXAMPLES
— ambient temperature;
— atmospheric pressure;
— presence of interfering gases in the flue gas matrix;
— pressure of the gas sample.
[SOURCE: JCGM 200:2012, examples have been adapted]
3.9
interference
negative or positive effect that a substance has upon the output of the P-AMS, when that substance is not
the measured component
[SOURCE: EN 15267-4:2017]
3.10
cross-sensitivity
response of the P-AMS to interferents
Note 1 to entry: See interference.
[SOURCE: EN 15267-4:2017]
3.11
lack of fit
systematic deviation, within the measurement range, between the accepted value of a reference material
applied to the measuring system and the corresponding result of measurement produced by the
calibrated measuring system
Note 1 to entry: In common language lack of fit is often called “linearity” or “deviation from linearity”. Lack of fit
test is often called “linearity test”.
[SOURCE: EN 15267-4:2017]
3.12
measurand
particular quantity subject to measurement
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.
[SOURCE: EN 15259:2007]
3.13
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]
3.14
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]
3.15
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]
3.16
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
quantity assigned to the P-AMS in order to define its performance
Note 1 to entry: The values of relevant performance characteristics are determined in the performance testing
and compared to the applicable performance criteria.
[SOURCE: EN 15267-4:2017]
3.18
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 measurement 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]
3.19
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 may be used if equivalence to the reference method has been demonstrated.
[SOURCE: EN 15259:2007]
3.20
repeatability
condition of measurement, out of a set of conditions that includes the same measurement procedure,
same operators, same measuring system, same operating conditions and same location, and replicable
measurements on the same or similar objects over a short period of time
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
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 document, 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 method;
— several sets of equipment, the performance 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 may be expressed quantitatively in terms of the dispersion characteristics of the
results.
Note 3 to entry: In this document, 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
t
time interval between the instant of a sudden change in the value of the input quantity to an AMS and the
time as from which the value of the output quantity is reliably maintained above 90 % of the correct value
of the input quantity
Note 1 to entry: The response time is also referred to as the 90 % time.
[SOURCE: EN 15267-3:2007]
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 or around the
emission limit value.
3.26
standard reference method
SRM
reference method prescribed by European or national legislation
[SOURCE: EN 15259:2007]
3.27
uncertainty
parameter associated with the result of a measurement, that characterises the dispersion of the values
that could reasonably be attributed to the measurand
[SOURCE: ISO/IEC Guide 98-3:2008]
3.28
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation u
[SOURCE: ISO/IEC Guide 98-3:2008]
3.29
combined standard uncertainty
standard uncertainty of the result of a measurement when that result is obtained from the values of a
number of other quantities, equal to the positive square root of a sum of terms, the terms being the
variances or covariances of these other quantities weighted according to how the measurement result
varies with changes in these quantities
[SOURCE: ISO/IEC Guide 98-3:2008]
3.30
expanded uncertainty
quantity defining a level of confidence about the result of a measurement that could be expected to
encompass a specific fraction of the distribution of values that could reasonably be attributed to a
measurand
[SOURCE: ISO/IEC Guide 98-3:2008]
Note 1 to entry: The interval about the result of measurement is established for a level of confidence of 95 %.
3.31
uncertainty budget
statement of a measurement uncertainty, of the components of that measurement uncertainty, and of
their calculation and combination
[SOURCE: JCGM 200:2012; Note 1 added]
Note 1 to entry: Calculation table combining all the sources of uncertainty according to EN ISO 14956 or
ISO/IEC Guide 98-3:2008.
4 Principle
4.1 General
This document specifies a method for the determination of the mass concentration of hydrogen chloride
(HCl) in ducts and stacks emitting to atmosphere by means of an automatic analyser using the infrared
absorption principle. The specific components and requirements for the sampling system and the
infrared analyser are described in Clause 5 and 6. A number of performance characteristics with
associated minimum performance criteria and an expanded uncertainty of the method are given.
Requirements and recommendations for quality assurance and quality control are given for
measurements in the field (see Table 1 in 7.3).
4.2 Measuring principle
The HCl concentration is measured with an infrared absorption method. The attenuation of infrared light
passing through a sample cell is a measure of the concentration of HCl in the cell, according to the
Lambert-Beer law. Not only HCl but also most hetero-atomic molecules absorb infrared light, in particular
water and CO have broad bands that can interfere with the measurement of HCl. Different technical
solutions have been developed to suppress cross-sensitivity, instability and drift in order to design
automatic monitoring systems with acceptable properties. For instance: Gas Filter Correlation, Tunable
Diode Laser (TDL) and Fourier Transform Infrared Spectroscopy (FTIR).
The P-AMS will be used only in the field of gas matrices tested during its characterization according to
EN 15267-4.
Infrared analysers are part of extractive or in situ systems. Most of them are combined with an extractive
sampling system and a gas conditioning system. A representative sample of gas is taken from the stack
with a sampling probe and conveyed to the analyser through the sampling line and gas conditioning
system. The values from the analyser are recorded and/or stored by means of electronic data processing.
The concentration of HCl is typically measured in parts per million by volume (ppmv). The final results
for reporting are expressed in milligrams per cubic meter using standard conversion factors (see
Clause 10).
5 Sampling system
5.1 General
A volume is extracted (see 8.2.1) from the flue gas for a fixed period of time at a controlled flow rate. A
filter removes the dust in the sampled volume before the sample is conditioned and passes to the
analyser. Two different sampling and conditioning configurations can be used in order to avoid
uncontrolled water vapour condensation in the measuring system. These configurations are:
— configuration 1: removal of water vapour through elimination using a permeation drier;
— configuration 2: maintaining the temperature of the sampling line at a minimum value (see 5.5.2) up
to the heated analyser.
Conditions and layout of the sampling equipment contribute to the expanded uncertainty. In order to
minimize this contribution to the expanded uncertainty of the method, sampling conditions are given in
5.2 and performance criteria for the sampling equipment in 7.2.
5.2 Sampling probe
In order to access the representative measurement point(s) 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 minimized in order to reduce the response
time of the measuring system. The probes shall be heated if they are not fully inserted into the duct or
stack.
The procedure described in 8.1 shall be used when a lack of homogeneity in the flue gas is suspected.
5.3 Filter
The filter shall be made of an inert material with an appropriate pore size. Use a heated filter appropriate
to the dust loading that shall be changed or cleaned periodically depending on the dust loading at the
sampling site.
Overloading of the particle filter could increase the pressure drop in the sampling line.
5.4 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. borosilicate glass or titanium could be used; PTFE is suitable for flue gas
temperatures lower than 200 °C).
5.5 Conditioning system
5.5.1 Permeation drier (configuration 1)
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 HCl.
In presence of few mg/m of ammonia, risk occurs to have salt deposition in the sampling line, potentially
clogging and damaging the permeation drier. This risk can be avoided using a scrubber specific to remove
NH installed at the outlet of the sampling probe. The remaining ammonia concentration shall not exceed
1 mg/m .
The temperature of the components coming into contact with the gas shall be maintained, upstream the
permeation system, at a sufficiently high temperature to prevent condensation.
This configuration is not recommended for water vapour content higher than 30 %.
The permeation drier is used before the gas enters the analyser in order to separate water vapour from
the flue gas. A water dew-point temperature below 4 °C is required at the outlet of the permeation drier.
The concentrations, provided by this sampling configuration, are considered to be given on dry basis.
However, the results may be corrected for the remaining water vapour (refer to the table of Annex B in
EN 14790:2017).
5.5.2 Heated line and heated analyser (configuration 2)
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 HCl.
In presence of few mg/m NH , risk occurs to have salts formation. The temperature of its components
coming into contact with the gas shall be maintained at a sufficiently high temperature to prevent salt
formation (typically between 175 °C and 200 °C) and higher than the water dew point to prevent
condensation in the sampling equipment.
If the concentrations are given on wet basis, they shall be corrected so that they are expressed on dry
basis. The correction shall be made from the water vapour concentration measured in the flue gas. The
uncertainty attached to this correction shall be part of the uncertainty budget.
5.6 Sample pump
The sample pump shall be capable of operating to the specified flow requirements of the manufacturer
of the analyser and pressure conditions required for the sample cell. The pump shall be resistant to
corrosion. If an external pump is used it shall be compatible with the requirements of the analyser to
which it is connected.
5.7 Secondary filter (optional)
The secondary filter is used to separate fine dust, with a pore size less than 5 µm. For example, it may be
made of glass-fibre, sintered ceramic, stainless steel or PTFE-fibre.

6 Analyser equipment
This document does not prescribe the technique. Instead, this document specifies performance criteria
(see EN 15267-4:2017, Table 1), regardless of the technique used to measure HCl. Additional
requirements described in method specific standards shall be observed, when they exist (e.g.
CEN/TS 17337 for P-AMS based on FTIR technique).
7 Determination of the characteristics of the method: analyser, sampling and
conditioning line
7.1 General
The user of this document shall demonstrate that:
— the performance characteristics of the P-AMS shall be equal or better than the associated
performance criteria given in EN 15267-4:2017, Table 1; and
— the expanded uncertainty of the method calculated by combining values of standard uncertainties
associated with the performance characteristics is less than 20 % at the daily emission limit value or
3 3
1 mg/m below 5 mg/m , in the measurement conditions, before correction to the specified value of
O and humidity.
The values of the performance characteristics shall be evaluated by an experienced and independent
laboratory recognized by the competent authority. Laboratory tests and a field test will be implemented
according to EN 15267-4. The P-AMS will be used only in the field of gas matrices tested during its
characterization according to EN 15267-4.
It is the responsibility of the user to check the performance characteristics with a periodicity given in
Table 2 (Clause 9).
7.2 Relevant performance characteristics of the method and performance criteria
The uncertainty of the measured values by the method is not only influenced by the performance
characteristics of the analyser itself but also by:
— the sampling line and conditioning system;
— the site-specific conditions;
— the reference material used (e.g. compressed gas in cylinders or gas provided by a gas generator).
The performance characteristics of the method shall be evaluated in accordance with EN 15267-4.
EN 15267-4:2017, Table 1 gives an overview of the relevant performance characteristics and
performance criteria, which shall be determined during laboratory and field tests according to the
relevant CEN procedures, and indicates values included in the calculation of the expanded uncertainty of
the method.
7.3 Establishment of the uncertainty budget
An uncertainty budget shall be established to determine if the analyser and its associated sampling
system fulfil the requirements for a maximum allowable expanded uncertainty of the method.

The method shall have an expanded uncertainty lower than 20 % at the daily emission limit value, or
3 3
1 mg/m for daily emissions limit values below 5 mg/m . This expanded uncertainty of the method is
calculated on a dry basis and before correction to the O reference concentration. If the concentrations of
the automated method are given on a wet basis, a correction to dry basis shall be carried out. The
uncertainty attached to the correction of water vapour content shall be added to the uncertainty budget.
An example of calculation is given in Annex A.
The principle of calculation of the expanded uncertainty of the method is based on the law on propagation
of uncertainty laid down in EN ISO 14956:
— determine the standard uncertainties for each value included in the calculation of the budget
uncertainty by means of laboratory and field tests, and according to EN ISO 14956;
— calculate the uncertainty budget by combining all the standard uncertainties according to
EN ISO 14956. This shall include the uncertainty of the certified reference material. It shall also take
variations in the range of influence quantities and interferents of the specific site conditions into
account. If these conditions are unknown, default values defined in Table 1 shall be applied. When
corrections for residual water content in the flue gas are applied, the uncertainty attached to this
correction shall be added to the uncertainty budget;
— values of standard uncertainty that are less than 5 % of the maximum standard uncertainty can be
neglected; and
— calculate the expanded uncertainty of the method at the daily emission limit value, on a dry basis.

Table 1 — Default variations ranges of influence quantities and interferents to be applied for the
determination of the uncertainty budget
Performance characteristic or component Default variations range on site
Atmospheric pressure ±3 kPa
In accordance with the manufacturer's
Sample volume flow variation
recommendations
a
Ambient temperature
between 5 °C and 40 °C
at −15 % below and at +10 % above nominal supply
Influence of voltage
voltage
O 3 % to 21 %
H O 1 % to 30 %
3 3
CO 0 mg/m to 300 mg/m
CO 0 % to 15 %
3 3
CH 0 mg/m to 50 mg/m
3 3
N O 0 mg/m to 20 mg/m
N O
3 3
0 mg/m to 100 mg/m
fluidised bed combustion
3 3
NO 0 mg/m to 300 mg/m
3 3
NO 0 mg/m to 30 mg/m
3 3
NH 0 mg/m to 20 mg/m
3 3
SO 0 mg/m to 200 mg/m
SO
3 3
0 mg/m to 1 000 mg/m
coal fired power plants (without
desulphurisation)
a
Bigger ranges can be specified by the manufacturer.
8 Field operation
8.1 Measurement plan and sampling strategy
The measurement plan and the sampling strategy shall be carried out in accordance with EN 15259
requirements.
The homogeneity can be demonstrated according to EN 15259.
To avoid long response times, the sample line shall be as short as possible. If necessary, a bypass pump
shall be used.
Typically, the following characteristics of flue gases should be considered before a field campaign:
— temperature of exhaust gases;
— flue gas moisture content and acid dew point;
— dust loading;
— presence of NH ;
— expected concentration range of HCl and emission limit values;
— expected concentration of potentially interfering substances, including at least the components listed
in Table 1; and
— flue gas cleaning system.
The measuring range shall be chosen to be adapted to the measuring task.
8.2 Setting of the analyser on site
8.2.1 General
The complete measuring system, the sampling line including the conditioning unit, where required and
the analyser, shall be connected according to the manufacturer’s instructions. The probe is inserted so
that its open end is at the representative measurement point(s) in the duct (see 8.1).
After pre-heating, the flow passing through the sampling system and the analyser shall be adjusted to the
chosen flow rate to be used during measurement. This flow should be maintained at a constant level.
The conditioning unit, where required, sampling probe, filter, connection tube and analyser shall be
stabilized with respect to temperature before adjustment of the analyser.
Time resolution of the data recording system shall be adapted to the measuring task and to the response
time of the measuring system.
8.2.2 Preliminary zero and span check, and adjustments
8.2.2.1 Test gases
The relative expanded uncertainty on the certified reference material used for the span check shall be no
more than 2,5 %.
The zero gas shall be a gas containing no significant amount of hydrogen chloride (for example, nitrogen
or purified air). For reasons given in C.3, the gas shall be wet.
When the analyser is used for regulatory purposes, the wet span gas shall have a known concentration of
approximately 50 % to 90 % of the chosen measuring range or at the concentration level of the site.
8.2.2.2 Adjustment of the analyser
At the beginning of the measuring period, the zero and span gases are supplied to the measurement port
of the analyser. Adjustments are made until the correct zero and span gas values are given by the data
sampling system.
8.2.2.3 Check of the sampling system, for leaks and losses
The sampling line shall be checked for leakage and losses according to the following procedure.
Zero and span gases are supplied to the analyser through the sampling system, as close as possible to the
inlet of the line (in front of the filter if possible). Differences between the readings obtained during the
adjustment of the analyser and during the check shall be lower than 2 % of P-AMS chosen measuring
range.
NOTE 1 A passivation time of several minutes could be required to reach a stable HCl reading.
If the leakage and losses test failed, follow manufacturer’s instructions.
NOTE 2 The cause being leakage can be eliminated by sealing off the end of the probe and switching on the pump
and checking that the flow rate does not exceed more than 2 % of the flow rate expected to be used during
measurement.
NOTE 3 Measuring oxygen at the entrance and at the exit of the sample gas line is a possible method to determine
if the failure is due to a leak (greater oxygen at the exit of the line) or losses (oxygen remains unchanged).
During the validation of this document, it has been noticed that some material might adsorb or desorb
HCl. With some P-AMS using stainless steel (probe, filter, connections) it has been observed desorption
phenomena when the probe is inserted into the duct that could affect the signal during more than 30 min.
The user should evaluate the importance of these phenomena to reduce their impact of this induced effect
and remove data corresponding to this affected period or reducing their importance by extending the
measurement time.
8.2.3 Zero and span checks after measurement
At the end of the measuring period and at least once a day, zero and span checks shall be performed at
the inlet of the sampling probe by supplying test gases. The results of these checks (i.e. deviations
between checks before and after measurement) shall be documented and included in the measurement
report.
If the span or zero drifts are greater than 2,0 % of the span value, it is necessary to correct both for zero
and span drifts.
The drift of zero and span shall be lower than 5,0 % of the span value; otherwise, the results shall be
rejected.
The concentration Ccorr corrected according to time t for the concentration C given by the analyser shall
be calculated according to Formula (1):
C− Bt + Drift B × t
( ( ) ( ) )
C = (1)
corr
At +×Drift A t
( ) ( )
( )
where
result after adjustment at tt at span – result after adjustment at at zero
A(t ) = ;
span gas concentration – zero gas concentration

result during the drift check at tt at span – result during the drift check at at zero
end end
Drift A − At
( ) ( )
span gas concentration – zero gas concentration
tt –

( )

...