ISO 11352

Water quality — Estimation of measurement uncertainty based on validation and quality control data

This document specifies approaches for the estimation of measurement uncertainty of chemical and physicochemical methods in single laboratories based on validation data and quality control data obtained within the field of water analysis. However, this approach can also be used in many other areas of chemical analysis. NOTE 1 The principles of the estimation of uncertainty specified in this document are consistent with the principles described in ISO/IEC Guide 98-3. In this document, the quantification of measurement uncertainty relies on performance characteristics of a measurement procedure obtained from validation and the results of internal and external quality control. NOTE 2 The approaches specified in this document are mainly based on Nordtest TR 537[ REF Reference_ref_4 \r \h 3 08D0C9EA79F9BACE118C8200AA004BA90B0200000008000000100000005200650066006500720065006E00630065005F007200650066005F0034000000 ], but also QUAM[ REF Reference_ref_5 \r \h 4 08D0C9EA79F9BACE118C8200AA004BA90B0200000008000000100000005200650066006500720065006E00630065005F007200650066005F0035000000 ], and Eurolab TR 1/2007[ REF Reference_ref_3 \r \h 2 08D0C9EA79F9BACE118C8200AA004BA90B0200000008000000100000005200650066006500720065006E00630065005F007200650066005F0033000000 ]. NOTE 3 This document only addresses the evaluation of measurement uncertainty for results obtained from quantitative measurement procedures. The uncertainties associated with results obtained from qualitative procedures are not considered.

Qualité de l'eau — Estimation de l'incertitude de mesure basée sur des données de validation et de contrôle qualité

Le présent document spécifie des approches pour l'estimation de l'incertitude de mesure des méthodes chimiques et physicochimiques dans des laboratoires individuels, basée sur des données de validation et sur les données du contrôle qualité obtenues dans le domaine de l'analyse de l'eau. Cependant, cette approche peut également être utilisée dans de nombreux autres domaines de l'analyse chimique. NOTE 1 Les principes de l'estimation de l'incertitude spécifiés dans le présent document sont en accord avec les principes décrits dans le Guide ISO/IEC 98-3. Dans le présent document, la quantification de l'incertitude de mesure repose sur les caractéristiques de performance d'un mode opératoire de mesure obtenues à partir de la validation et des résultats du contrôle qualité interne et externe. NOTE 2 Les approches spécifiées dans le présent document sont principalement fondées sur le Nordtest TR 537,[ REF Reference_ref_4 \r \h 3 08D0C9EA79F9BACE118C8200AA004BA90B0200000008000000100000005200650066006500720065006E00630065005F007200650066005F0034000000 ] mais également sur QUAM[ REF Reference_ref_5 \r \h 4 08D0C9EA79F9BACE118C8200AA004BA90B0200000008000000100000005200650066006500720065006E00630065005F007200650066005F0035000000 ] et l'Eurolab TR 1/2007[ REF Reference_ref_3 \r \h 2 08D0C9EA79F9BACE118C8200AA004BA90B0200000008000000100000005200650066006500720065006E00630065005F007200650066005F0033000000 ]. NOTE 3 Le présent document traite uniquement de l'évaluation de l'incertitude de mesure pour des résultats obtenus à partir de modes opératoires de mesures quantitatives. Les incertitudes associées aux résultats obtenus à partir de modes opératoires de mesures qualitatives ne sont pas prises en compte.

General Information

• Status: Not Published
• ICS: 13.060.45 - Examination of water in general
• Technical Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Drafting Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Current Stage: 6000 - International Standard under publication
• Start Date: 26-Jun-2025
• Completion Date: 30-Aug-2025

Relations

• Revises: ISO 11352:2012 - Water quality — Estimation of measurement uncertainty based on validation and quality control data
• Effective Date: 29-Apr-2023

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 11352
ISO/TC 147/SC 2
Water quality — Estimation of
Secretariat: DIN
measurement uncertainty based on
Voting begins on:
validation and quality control data
2025-04-30
Qualité de l'eau — Estimation de l'incertitude de mesure basée
Voting terminates on:
sur des données de validation et de contrôle qualité
2025-06-25
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 11352:2025(en) © ISO 2025

FINAL DRAFT
ISO/FDIS 11352:2025(en)
International
Standard
ISO/FDIS 11352
ISO/TC 147/SC 2
Water quality — Estimation of
Secretariat: DIN
measurement uncertainty based on
Voting begins on:
validation and quality control data
Qualité de l'eau — Estimation de l'incertitude de mesure basée
Voting terminates on:
sur des données de validation et de contrôle qualité
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 11352:2025(en) © ISO 2025

ii
ISO/FDIS 11352:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Principle . 5
6 Procedure . 5
7 Preparative considerations for the estimation of measurement uncertainty . 6
7.1 Specification of the measurement .6
7.2 Specification of the parametric form in which the measurement uncertainty is reported .6
8 Evaluation of available data for within-laboratory reproducibility and bias . 7
8.1 Approach and criteria .7
8.2 Within-laboratory reproducibility .8
8.2.1 General .8
8.2.2 Quality control samples covering the whole analytical process .9
8.2.3 Using standard solutions and replicates of test samples .9
8.2.4 No stable quality control samples .10
8.3 Bias .10
8.3.1 General .10
8.3.2 Analysis of suitable reference materials .11
8.3.3 Participation in interlaboratory comparisons . 12
8.3.4 Recovery experiments. 13
9 Calculation of the combined standard uncertainty .15
10 Calculation of the expanded uncertainty .15
11 Initial estimation of measurement uncertainty from reproducibility standard deviation .16
12 Report .16
Annex A (informative) Division of the measurement range into two parts — Constant absolute
and constant relative uncertainties . 17
Annex B (normative) Estimation of the pooled standard deviation from replicate measurements .24
Annex C (informative) Examples of the estimation of measurement uncertainty .25
Bibliography .38

iii
ISO/FDIS 11352:2025(en)
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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 147, Water quality, Subcommittee SC 2,
Physical, chemical and biochemical methods.
This second edition cancels and replaces the first edition (ISO 11352:2012), which has been technically
revised.
The main changes are as follows:
— requirements for measurements for estimation of uncertainty component for the within-laboratory
reproducibility have been changed from at least eight to 20 replicates with exception of a first estimation,
— the use of data from target control charts estimation of precision is described
— a new informative annex has been introduced to describe how to divide the measurement range into two
parts for constant absolute and constant relative uncertainties,
— In Annex B (former Annex A) the estimation of the standard uncertainty from range control charts has
been changed to the use of pooled standard deviation,
— the examples in Annex C have been adjusted,
— this document has been editorially revised.
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/FDIS 11352:2025(en)
Introduction
[1]
The basic principles of the estimation of measurement uncertainty are set out in ISO/IEC Guide 98-3.
There are several ways of estimating measurement uncertainty depending on the purpose of the estimation
[2]
and the available data; Eurolab TR 1/2007 gives an overview of the main approaches.
This document specifies a set of procedures to enable laboratories to estimate the measurement uncertainty
of their results, using an approach based on validation and quality control data. Validation data can be used
for first estimates of the measurement uncertainty, but should later be confirmed with data from quality
control, when the method is in routine use. It is structured in a way that is applicable to analysts that do not
have a thorough understanding of metrology or statistics.
[3]
Nordtest TR 537 has been used as a basis for developing this document. The approach taken is “top-down”,
[1]
contrary to the mainly “bottom-up” strategy adopted in ISO/IEC Guide 98-3 .
It is statistically acceptable to combine the uncertainty components associate with within-laboratory
reproducibility for random error and the uncertainty associated the bias for systematic error into a single
measure of uncertainty. The sources of data for this approach are validation and analytical quality control.
The experimental approach specified in this document enables a good coverage of the sources of variation
observed during routine use of the analytical method.

v
FINAL DRAFT International Standard ISO/FDIS 11352:2025(en)
Water quality — Estimation of measurement uncertainty
based on validation and quality control data
1 Scope
This document specifies approaches for the estimation of measurement uncertainty of chemical and
physicochemical methods in single laboratories based on validation data and quality control data obtained
within the field of water analysis. However, this approach can also be used in many other areas of chemical
analysis.
NOTE 1 The principles of the estimation of uncertainty specified in this document are consistent with the principles
described in ISO/IEC Guide 98-3.
In this document, the quantification of measurement uncertainty relies on performance characteristics of a
measurement procedure obtained from validation and the results of internal and external quality control.
[3] [4]
NOTE 2 The approaches specified in this document are mainly based on Nordtest TR 537 , but also QUAM , and
[2]
Eurolab TR 1/2007 .
NOTE 3 This document only addresses the evaluation of measurement uncertainty for results obtained from
quantitative measurement procedures. The uncertainties associated with results obtained from qualitative
procedures are not considered.
2 Normative references
The following documents are referred to in the text in such a wa
...

ISO/FDIS 11352:2025(en)
ISO/TC 147/SC 2/WG 48
Secretariat: DIN
Date: 2025-04-16
Water quality — Estimation of measurement uncertainty based on
validation and quality control data
Qualité de l'eau — Estimation de l'incertitude de mesure basée sur des données de validation et de contrôle
qualité
Second edition
Date: 2025-01-31
FDIS stage
ISO/FDIS 11352:2025(en)
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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/FDIS 11352:2025(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Principle . 5
6 Procedure . 5
7 Preparative considerations for the estimation of measurement uncertainty . 6
8 Evaluation of available data for within-laboratory reproducibility and bias . 8
9 Calculation of the combined standard uncertainty . 17
10 Calculation of the expanded uncertainty . 17
11 Initial estimation of measurement uncertainty from reproducibility standard deviation17
12 Report . 18
Annex A (informative) Division of the measurement range into two parts — Constant absolute
and constant relative uncertainties . 19
Annex B (normative) Estimation of the pooled standard deviation from replicate measurements30
Annex C (informative) Examples of the estimation of measurement uncertainty . 31
Bibliography . 45

iii
ISO/FDIS 11352:2025(en)
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).
Field Code Changed
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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.
Field Code Changed
This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2,
Physical, chemical and biochemical methods.
This second edition cancels and replaces the first edition (ISO 11352:2012), which has been technically
revised.
The main changes are as follows:
— — requirements for measurements for estimation of uncertainty component for the within-laboratory
reproducibility have been changed from at least eight to twenty20 replicates with exception of a first
estimation,
— — the use of data from target control charts estimation of precision is described
— — a new informative annex has been introduced to describe how to divide the measurement range into
two parts for constant absolute and constant relative uncertainties,
— — In Annex BAnnex B (former Annex AAnnex A)) the estimation of the standard uncertainty from range
control charts has been changed to the use of pooled standard deviation,
— — the examples in Annex CAnnex C have been adjusted,
— — this document has been editorially revised.
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/FDIS 11352:2025(en)
Introduction
[ [1] ]
The basic principles of the estimation of measurement uncertainty are set out in ISO/IEC Guide 98--3. 0 .
There are several ways of estimating measurement uncertainty depending on the purpose of the estimation
[ [2]]
and the available data; Eurolab TR 1/2007 0 gives an overview of the main approaches.
This document specifies a set of procedures to enable laboratories to estimate the measurement uncertainty
of their results, using an approach based on validation and quality control data. Validation data can be used
for first estimates of the measurement uncertainty, but should later be confirmed with data from quality
control, when the method is in routine use. It is structured in a way that is applicable to analysts that do not
have a thorough understanding of metrology or statistics.
[ [3]]
Nordtest TR 537 0 has been used as a basis for developing this document. The approach taken is “top-
[ [1] ]
down”, contrary to the mainly “bottom-up” strategy adopted in ISO/IEC Guide 98-3 0 . .
It is statistically acceptable to combine the uncertainty components associate with within-laboratory
reproducibility for random error and the uncertainty associated the bias for systematic error into a single
measure of uncertainty. The sources of data for this approach are validation and analytical quality control. The
experimental approach specified in this document enables a good coverage of the sources of variation
observed during routine use of the analytical method.
v
ISO/FDIS 11352:2025(en)
Water quality — Estimation of measurement uncertainty based on
validation and quality control data
1 Scope
This document specifies approaches for the estimation of measurement uncertainty of chemical and
physicochemical methods in single laboratories based on validation data and quality control data obtained
within the field of water analysis. However, this approach can also be used in many other areas of chemical
analysis.
NOTE 1 The principles of the estimation of uncertainty specified in this document are consistent with the principles
described in ISO/IEC Guide 98-3.
In this document, the quantification of measurement uncertainty relies on performance characteristics of a
measurement procedure obtained from validation and the results of internal and external quality control.
[ [3]] [ [4]]
NOTE 2 The approaches specified in this document are mainly based on Nordtest TR 537 0, , but also QUAM 0, ,
[ [2] ]
and Eurolab TR 1/2007 0 . .
NOTE 3 This document only addresses the evaluation of measurement uncertainty for results obtained from
quantitative measurement procedures. The uncertainties associated with results obtained from qualitative procedures
are not considered.
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/IEC Guide 99:2007, International vocabulary of metrology -— Basic and general concepts and associated
terms (VIM)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC Guide 99 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1 3.1
precision
measurement precision
closeness of agreement between indications or measured quantity values obtained by replicate measurements
on the same or similar objects under specified conditions
[SOURCE: ISO/IEC Guide 99:2007 2.15, modified — Notes 1 to 4 to entry have been deleted.]
ISO/FDIS 11352:2025(en)
3.2 3.2
error
measurement error
measured quantity value minus a reference quantity value
[SOURCE: ISO/IEC Guide 99:2007, 2.16, modified — the admitted term "error of measurement" and Notes 1
and 2 to entry have been deleted.]
3.3 3.3
systematic error
systematic measurement error
component of measurement error (3.2(3.2)) that in replicate measurements remains constant or varies in a
predictable manner
[SOURCE: ISO/IEC Guide 99:2007, 2.17, modified — the admitted term "systematic error of measurement"
and Notes 1 to 3 to entry have been deleted.]
3.4 3.4
bias
measurement bias
estimate of a systematic measurement error (3.3(3.3))
[SOURCE: ISO/IEC Guide 99:2007, 2.18]
3.5 3.5
random error
random measurement error
component of measurement error (3.2(3.2)) that in replicate measurements varies in an unpredictable manner
[SOURCE: ISO/IEC Guide 99:2007, 2.19, modified — Notes 1 to 3 to entry have been deleted.]
3.6 3.6
repeatability condition
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 replicate
measurements on the same or similar objects over a short period of time
[SOURCE: ISO/IEC Guide 99:2007, 2.20, modified — the term "repeatability condition of measurement" and
Notes 1 and 2 to entry have been deleted.]
3.7 3.7
repeatability
measurement precision (3.1(3.1)) under a set of repeatability conditions (3.6(3.7)) of measurement
[SOURCE: ISO/IEC Guide 99:2007, 2.21], modified — the term "measurement repeatability" has been deleted.]
3.8 3.8
analytical run
series of measurements made under repeatability conditions (3.6(3.6))
3.9 3.9
within-laboratory reproducibility
intermediate measurement precision (3.1)where all variations that occur within one laboratory are included
Note 1 to entry: Intermediate measurement precision is defined in ISO/IEC Guide 99: 2007, 2.23.
ISO/FDIS 11352:2025(en)
3.10 3.10
reproducibility condition
condition of measurement, out of a set of conditions that includes different locations, operators, measuring
systems, and replicate measurements on the same or similar objects
[SOURCE: ISO/IEC Guide 99:2007, 2.24, modified — the term "reproducibility condition of measurement"
Notes 1 and 2 to entry have been deleted.]
3.11 3.11
reproducibility
measurement precision (3.1(3.1)) under reproducibility conditions (3.10(3.10)) of measurement
[SOURCE: ISO/IEC Guide 99:2007, 2.25, modified — the term "measurement reproducibility" and Note has1
to entry have been deleted.]
3.12 3.12
uncertainty
measurement uncertainty
non-negative parameter characterizing the dispersion of the quantity values being attributed to a measurand,
based on the information used
[SOURCE: ISO/IEC Guide 99:2007, 2.26, modified — Notes 1 to 4 to entry have been deleted.]
3.13 3.13
standard uncertainty
standard measurement uncertainty
measurement uncertainty (3.12(3.12)) expressed as a standard deviation
[SOURCE: ISO/IEC Guide 99:2007, 2.30], modified — the admitted term "standard uncertainty of
measurement" has been deleted.]
3.14 3.14
combined standard uncertainty
combined standard measurement uncertainty
standard measurement uncertainty (3.13(3.13)) that is obtained using the individual standa
...

PROJET FINAL
Norme
internationale
ISO/FDIS 11352
ISO/TC 147/SC 2
Qualité de l'eau — Estimation de
Secrétariat: DIN
l'incertitude de mesure basée sur
Début de vote:
des données de validation et de
2025-04-30
contrôle qualité
Vote clos le:
2025-06-25
Water quality — Estimation of measurement uncertainty based
on validation and quality control data
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
OUTRE LE FAIT D’ÊTRE EXAMINÉS POUR
ÉTABLIR S’ILS SONT ACCEPTABLES À DES FINS
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AINSI QUE DU POINT DE VUE DES UTILISATEURS, LES
PROJETS DE NORMES
INTERNATIONALES DOIVENT PARFOIS ÊTRE CONSIDÉRÉS
DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
NORMES POUVANT
SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
Numéro de référence
ISO/FDIS 11352:2025(fr) © ISO 2025

PROJET FINAL
ISO/FDIS 11352:2025(fr)
Norme
internationale
ISO/FDIS 11352
ISO/TC 147/SC 2
Qualité de l'eau — Estimation de
Secrétariat: DIN
l'incertitude de mesure basée sur
Début de vote:
des données de validation et de
2025-04-30
contrôle qualité
Vote clos le:
2025-06-25
Water quality — Estimation of measurement uncertainty based
on validation and quality control data
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
DOCUMENT PROTÉGÉ PAR COPYRIGHT
OUTRE LE FAIT D’ÊTRE EXAMINÉS POUR
ÉTABLIR S’ILS SONT ACCEPTABLES À DES FINS
© ISO 2025 INDUSTRIELLES, TECHNOLOGIQUES ET COM-MERCIALES,
AINSI QUE DU POINT DE VUE DES UTILISATEURS, LES
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
PROJETS DE NORMES
INTERNATIONALES DOIVENT PARFOIS ÊTRE CONSIDÉRÉS
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
NORMES POUVANT
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: [phone]
E-mail: [e-mail]
Web: www.iso.org
Publié en Suisse Numéro de référence
ISO/FDIS 11352:2025(fr) © ISO 2025

ii
ISO/FDIS 11352:2025(fr)
Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d'application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Symboles . 4
5 Principe. 5
6 Mode opératoire . 6
7 Considérations préalables à l'estimation de l'incertitude de mesure . 6
7.1 Description du mesurage .6
7.2 Description du support d'enregistrement dans lequel l'incertitude de mesure est
rapportée .6
8 Évaluation des données disponibles pour la reproductibilité intralaboratoire et le biais . 7
8.1 Approche et critères .7
8.2 Reproductibilité intralaboratoire .8
8.2.1 Généralités .8
8.2.2 Échantillons de contrôle qualité subissant l'intégralité du processus analytique .9
8.2.3 Utilisation de solutions étalons et de répétitions d'échantillons d'essai .9
8.2.4 Aucun échantillon de contrôle qualité stable .10
8.3 Biais .10
8.3.1 Généralités .10
8.3.2 Analyse de matériaux de référence appropriés .11
8.3.3 Participation à des comparaisons interlaboratoires . 12
8.3.4 Études de rendement .14
9 Calcul de l'incertitude-type composée .16
10 Calcul de l'incertitude élargie.16
11 Estimation initiale de l'incertitude de mesure à partir de l'écart-type de la
reproductibilité . 16
12 Rapport .16
Annexe A (informative) Division de l'étendue de mesure en deux parties — Incertitude absolue
et incertitude relative constantes .18
Annexe B (normative) Estimation de l'écart-type regroupé à partir de mesurages répétés .25
Annexe C (informative) Exemples d'estimation de l'incertitude de mesure .26
Bibliographie .39

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ISO/FDIS 11352:2025(fr)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux
de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général
confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire
partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document
a été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
(voir www.iso.org/directives).
L'ISO attire l'attention sur le fait que la mise en application du présent document peut entraîner l'utilisation
d'un ou de plusieurs brevets. L'ISO ne prend pas position quant à la preuve, à la validité et à l'applicabilité
de tout droit de propriété revendiqué à cet égard. À la date de publication du présent document, l'ISO
n'avait pas reçu notification qu'un ou plusieurs brevets pouvaient être nécessaires à sa mise en application.
Toutefois, il y a lieu d'avertir les responsables de la mise en application du présent document que des
informations plus récentes sont susceptibles de figurer dans la base de données de brevets, disponible à
l'adresse www.iso.org/brevets. L'ISO ne saurait être tenue pour responsable de ne pas avoir identifié tout ou
partie de tels droits de brevet.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données pour
information, par souci de commodité, à l'intention des utilisateurs et ne sauraient constituer un engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion de
l'ISO aux principes de l'Organisation mondiale du commerce (OMC) concernant les obstacles techniques au
commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 147, Qualité de l'eau, sous-comité SC 2,
Méthodes physiques, chimiques et biochimiques.
Cette deuxième édition annule et remplace la première édition (ISO 11352:2012), qui a fait l'objet d'une
révision technique.
Les principales modifications sont les suivantes:
— les exigences relatives aux mesures pour l'estimation du composant d'incertitude pour la reproductibilité
intralaboratoire ont été modifiées avec au moins 8 à 20 répétitions, à l'exception d'une estimation
préliminaire;
— l'utilisation des données provenant des cartes de contrôle cible pour l'estimation de la fidélité est décrite;
— introduction d'une nouvelle annexe informative pour décrire la manière de diviser l'étendue de mesure
en deux parties pour des incertitudes absolues et des incertitudes relatives constantes;
— à l'Annexe B (anciennement l'Annexe A), modification du calcul de l'incertitude des cartes de contrôle de
l'étendue en utilisant des écarts-types regroupés;
— modification des exemples à l'Annexe C;
— le présent document a fait l'objet d'une révision éditoriale.
Il convient que l'utilisateur adresse tout retour d'information ou toute question concernant le présent
document à l'organisme national de normalisation de son pays. Une liste exhaustive desdits organismes se
trouve à l'adresse www.iso.org/fr/members.html.

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ISO/FDIS 11352:2025(fr)
Introduction
[1]
Les principes de base de l'estimation de l'incertitude de mesure sont énoncés dans le Guide ISO/IEC 98-3 .
Il existe plusieurs façons d'estimer l'incertitude de mesure en fonction de l'objectif de l'estimation et des
[2]
données disponibles; Eurolab TR 1/2007 donne une vue d'ensemble des principales approches.
Le présent document spécifie un ensemble de modes opératoires visant à permettre aux laboratoires
d'estimer l'incertitude de mesure de leurs résultats, au moyen d'une approche basée sur les données de
validation et de contrôle qualité. Les données de validation peuvent être utilisées pour les estimations
préliminaires de l'incertitude de mesure, mais il convient de les confirmer ultérieurement avec les données
du contrôle qualité, lorsque la méthode est utilisée en routine. Elle est structurée de manière à pouvoir être
appliquée par des analystes qui n'ont pas de connaissances approfondies en métrologie ou en statistiques.
[3]
Le Nordtest TR 537 a servi de base pour l'élaboration du présent document. L'approche présentée
est de type «descendant», contrairement à la stratégie principalement «ascendante» adoptée dans le
[1]
Guide ISO/IEC 98-3 .
Il est statistiquement acceptable de combiner les composantes d'incertitude associées à la reproductibilité
intralaboratoire pour l'erreur aléatoire et l'incertitude associée au biais pour l’'erreur systématique dans
une seule mesure d'incertitude. Les données utilisées pour cette approche proviennent de la validation et du
contrôle qualité analytique. L'approche expérimentale spécifiée dans le présent document offre une bonne
couverture des sources de variation observées lors de l'utilisation de routine de la m
...