SIST EN ISO 4259-3:2020
(Main)Petroleum and related products - Precision of measurement methods and results - Part 3: Monitoring and verification of published precision data in relation to methods of test (ISO 4259-3:2020)
Petroleum and related products - Precision of measurement methods and results - Part 3: Monitoring and verification of published precision data in relation to methods of test (ISO 4259-3:2020)
This International Standard specifies the methodology for the regular monitoring of the test method
precision achieved versus precision published in the standard test method using data from Proficiency
Testing Programs (PTP) supported by the regular users of standard test methods.
The procedures in this International Standard are designed specifically for PTPs conducted on standard
test methods for petroleum and petroleum related products, which are presumed to be homogeneous.
The procedures in this document are designed specifically for standard test methods with published
reproducibility derived from ISO 4259-1 or equivalent (such as ASTM D6300[1]) for petroleum and
petroleum related products, which are normally considered as homogeneous.
In particular, this document specifies the methodology for the statistical comparison of standard
deviation under reproducibility conditions achieved in PTP versus that published.
Purpose of this comparison is to ascertain if the published reproducibility precision is representative of
that achievable by the regular participants in the PTP.
Mineralölerzeugnisse - Präzision von Messverfahren und Ergebnissen - Teil 3: Monitoring und Management der Präzisionsdaten in Bezug auf Prüfverfahren (ISO 4259-3:2020)
Dieses Dokument legt die Methodik fest für das regelmäßige Monitoring der durch Prüfverfahren erreichten Präzision im Vergleich zu der nach Standardprüfverfahren veröffentlichten Präzision, unter Verwendung von Eignungsprüfungsprogrammen (PTS, en: proficiency testing scheme), die von den regelmäßigen Anwendern der Standardprüfverfahren unterstützt werden.
Die Verfahren nach diesem Dokument sind speziell für Eignungsprüfungen (PT, en: proficiency testing) ausgelegt, die in Bezug auf Standardprüfverfahren mit einer veröffentlichten Vergleichbarkeit für Mineral¬ölerzeugnisse und verwandte Produkte durchgeführt werden, die im Allgemeinen als homogene Produkte angesehen werden und bei denen die Daten annähernd normal verteilt sind. Zusätzlich ist es anwendbar für zu betrachtende Eigenschaften, die (bekanntermaßen) über die Zeit und den Transport stabil sind.
Dieses Dokument legt die Methodik für den statistischen Vergleich der Standardabweichung, die in Eignungsprüfprogrammen unter Vergleichbarkeitsbedingungen erreicht wurde, mit der veröffentlichten Vergleichbarkeit fest.
Der Zweck dieses Vergleichs ist herauszufinden, ob die veröffentlichte Präzision der Vergleichbarkeit repräsentativ ist für die, die übliche Teilnehmer in Eignungsprüfprogrammen erreichen können.
Dieses Dokument enthält auch einen Leitfaden zur Verwendung eines z-Werts der PT zur Überwachung der Leistung eines einzelnen Teilnehmers über die Zeit (siehe Anhang B).
Produits pétroliers et connexes - Fidélité des méthodes de mesure et de leurs résultats - Partie 3: Surveillance et vérification des données de fidélité publiées relatives aux méthodes d'essai (ISO 4259-3:2020)
Le présent document spécifie la méthodologie applicable pour la surveillance régulière de la fidélité obtenue selon la méthode d'essai comparativement à celle publiée dans la méthode d'essai normalisée à l'aide des programmes d'essais d'aptitude (PTS) étayés par les utilisateurs réguliers de méthodes d'essai normalisées.
Les modes opératoires décrits dans le présent document sont spécifiquement conçus pour les essais d'aptitude (PT) réalisés sur des méthodes d'essai normalisées, pour lesquelles une fidélité a été établie, portant sur des produits pétroliers et connexes qui sont supposés homogènes et dont les données suivent une distribution approximativement normale.
En outre, le document est applicable aux caractéristiques qui sont (connues pour être) stables dans le temps et pendant le transport.
Le présent document spécifie la méthodologie de comparaison statistique des écarts-type dans les conditions de reproductibilité obtenues dans les programmes d'essais d'aptitude par rapport aux conditions publiées.
Cette comparaison vise à déterminer si la fidélité de la reproductibilité telle qu'elle est publiée est représentative de celle susceptible d'être obtenue par les participants réguliers aux programmes d'essais d'aptitude.
Enfin, ce document fournit également des recommandations sur l'utilisation du score z de l'essai d'aptitude pour contrôler les performances dans le temps d'un participant donné (voir Annexe B).
Nafta in sorodni proizvodi - Natančnost merilnih metod in rezultatov - 3. del: Spremljanje in upravljanje podatkov o natančnosti pri preskusnih metodah (ISO 4259-3:2020)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 4259-3:2020
01-april-2020
Nafta in sorodni proizvodi - Natančnost merilnih metod in rezultatov - 3. del:
Spremljanje in upravljanje podatkov o natančnosti pri preskusnih metodah (ISO
4259-3:2020)
Petroleum and related products - Precision of measurement methods and results - Part
3: Monitoring and verification of published precision data in relation to methods of test
(ISO 4259-3:2020)
Mineralölerzeugnisse - Präzision von Messverfahren und Ergebnissen - Teil 3:
Monitoring und Management der Präzisionsdaten in Bezug auf Prüfverfahren (ISO 4259-
3:2020)
Produits pétroliers et connexes - Fidélité des méthodes de mesure et de leurs résultats -
Partie 3: Surveillance et vérification des données de fidélité publiées relatives aux
méthodes d'essai (ISO 4259-3:2020)
Ta slovenski standard je istoveten z: EN ISO 4259-3:2020
ICS:
75.080 Naftni proizvodi na splošno Petroleum products in
general
75.180.30 Oprema za merjenje Volumetric equipment and
prostornine in merjenje measurements
SIST EN ISO 4259-3:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 4259-3:2020
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SIST EN ISO 4259-3:2020
EN ISO 4259-3
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2020
EUROPÄISCHE NORM
ICS 75.080
English Version
Petroleum and related products - Precision of
measurement methods and results - Part 3: Monitoring
and verification of published precision data in relation to
methods of test (ISO 4259-3:2020)
Produits pétroliers et connexes - Fidélité des méthodes Mineralölerzeugnisse - Präzision von Messverfahren
de mesure et de leurs résultats - Partie 3: Surveillance und Ergebnissen - Teil 3: Monitoring und Management
et vérification des données de fidélité publiées der Präzisionsdaten in Bezug auf Prüfverfahren (ISO
relatives aux méthodes d'essai (ISO 4259-3:2020) 4259-3:2020)
This European Standard was approved by CEN on 11 January 2020.
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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4259-3:2020 E
worldwide for CEN national Members.
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SIST EN ISO 4259-3:2020
EN ISO 4259-3:2020 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 4259-3:2020
EN ISO 4259-3:2020 (E)
European foreword
This document (EN ISO 4259-3:2020) has been prepared by Technical Committee ISO/TC 28
"Petroleum and related products, fuels and lubricants from natural or synthetic sources" in
collaboration with Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related
products of petroleum, synthetic and biological origin.” the secretariat of which is held by NEN.
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 August 2020, and conflicting national standards shall
be withdrawn at the latest by August 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 4259-3:2020 has been approved by CEN as EN ISO 4259-3:2020 without any
modification.
3
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SIST EN ISO 4259-3:2020
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SIST EN ISO 4259-3:2020
INTERNATIONAL ISO
STANDARD 4259-3
First edition
2020-01
Petroleum and related products —
Precision of measurement methods
and results —
Part 3:
Monitoring and verification of
published precision data in relation to
methods of test
Produits pétroliers et connexes — Fidélité des méthodes de mesure et
de leurs résultats —
Partie 3: Surveillance et vérification des données de fidélité publiées
relatives aux méthodes d'essai
Reference number
ISO 4259-3:2020(E)
©
ISO 2020
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SIST EN ISO 4259-3:2020
ISO 4259-3:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 4259-3:2020
ISO 4259-3:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Proficiency testing scheme requirement . 2
4.1 PTS provider . 2
4.2 PT homogeneity and stability of proficiency test items . 2
4.2.1 Property homogeneity . 2
4.2.2 PT data and statistics requirement . 2
5 Comparison of PT precision achieved to published precision . 3
5.1 General . 3
5.2 Perform F-test on the variance ratio . 3
5.2.1 Construction of the variance ratio to be used for the F-test . 3
5.2.2 Comparison of variance ratio to be tested to a critical value F . 4
_crit_,025
5.2.3 Multiple comparisons overtime . 9
Annex A (informative) Worked examples of F-test .10
Annex B (informative) Use of z-scores to monitor an individual participant’s PT performance .11
Bibliography .14
© ISO 2020 – All rights reserved iii
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SIST EN ISO 4259-3:2020
ISO 4259-3:2020(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 28, Petroleum and related products, fuels
and lubricants from natural or synthetic sources, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 19, Gaseous and liquid fuels, lubricants and related
products of petroleum, synthetic and biological origin, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 4259 series can be found on the ISO website.
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 2020 – All rights reserved
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SIST EN ISO 4259-3:2020
ISO 4259-3:2020(E)
Introduction
ISO 4259-1 specifies the methodology for the design, execution and data processing of a one-
time snapshot statistical study to arrive at precision estimates achieved by a random sampling of
laboratories. This snapshot estimate is published in the standard test method as the expected precision.
This document explains the methodology for the utilisation of proficiency testing schemes (as defined
in ISO 4259-2) to test the hypothesis that the precision achieved by the laboratories in the proficiency
testing scheme is statistically consistent with the published precision derived from the ISO 4259-1
study described above. It is therefore a logical follow-up on the other parts.
© ISO 2020 – All rights reserved v
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SIST EN ISO 4259-3:2020
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SIST EN ISO 4259-3:2020
INTERNATIONAL STANDARD ISO 4259-3:2020(E)
Petroleum and related products — Precision of
measurement methods and results —
Part 3:
Monitoring and verification of published precision data in
relation to methods of test
1 Scope
This document specifies the methodology for the regular monitoring of the test method precision
achieved versus the precision published in the standard test method using data from proficiency testing
schemes (PTSs) supported by the regular users of standard test methods.
The procedures in this document are designed specifically for proficiency testing (PT) conducted
on standard test methods, having a published reproducibility, for petroleum and petroleum-related
products, which are presumed to be homogeneous, and where the data distribution is approximately
normal. In addition, it is applicable to properties of interest that are (known to be) stable over time and
transport.
This document specifies the methodology for the statistical comparison of standard deviation under
reproducibility conditions achieved in PT programmes versus that published.
The purpose of this comparison is to find out if the published reproducibility precision is representative
of that achievable by the regular participants in the PT programmes.
This document also provides guidance on how to use a PT z-score to monitor an individual participant’s
performance over time (see Annex B).
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 4259-1, Petroleum and related products — Precision of measurement methods and results — Part 1:
Determination of precision data in relation to methods of test
ISO 13528:2015, Statistical methods for use in proficiency testing by interlaboratory comparison
ISO/IEC 17043, Conformity assessment — General requirements for proficiency testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4259-1, ISO 13528,
ISO/IEC 17043 and the following 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 2020 – All rights reserved 1
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SIST EN ISO 4259-3:2020
ISO 4259-3:2020(E)
3.1
proficiency testing
PT
evaluation of participant performance against pre-established criteria by means of interlaboratory
comparisons
3.2
proficiency testing scheme
PTS
programme designed for the periodic evaluation of participating laboratories’ proficiency in the
execution of a standard test method through the statistical analysis of their test results obtained on
aliquots prepared from a single batch of homogeneous material
Note 1 to entry: The frequency of such testing varies in accordance with the scheme objective. Each execution of
testing involves testing of a single batch of material. Materials typically vary from test to test.
Note 2 to entry: This is also commonly referred to as the “Inter Laboratory Cross Check Programme”.
4 Proficiency testing scheme requirement
4.1 PTS provider
The PTS provider shall conform to the technical and management requirements as outlined in
ISO/IEC 17043.
4.2 PT homogeneity and stability of proficiency test items
4.2.1 Property homogeneity
The assessment of property homogeneity shall be performed after the proficiency test items have been
packaged in the final form and before distribution to participants. Consult and follow ISO 13528:2015,
Annex B, as appropriate.
4.2.2 PT data and statistics requirement
The comparison methodology in this document is intended for PT data and statistics meeting the
following requirements.
a) The PT data requirements are as follows.
1) Data are obtained using a common standard test method with a published reproducibility
obtained in accordance with ISO 4259-1 or equivalent.
2) Data are all numeric (i.e. do not contain results such as < xxx or > xxx).
3) A single result only is reported by each participant (i.e. no repeat).
b) The PT statistics requirements are as follows.
The following statistics are required to be provided as part of the PTS report for each round.
a) PT statistics (average and standard deviation) shall be based on at least 10 results, where
at least 16 is strongly recommended, with at least 6 uniquely different values, after outlier
rejection in accordance with the generalized extreme studentized deviation (GESD) as
described in ISO 4259-1 or an equivalent technique.
NOTE 1 PT data with insufficient resolution due to rounding (e.g. cold flow properties of diesel fuel)
can invalidate the last requirement (a minimum of six uniquely different values).
2 © ISO 2020 – All rights reserved
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SIST EN ISO 4259-3:2020
ISO 4259-3:2020(E)
b) Data distribution is approximately normal as assessed by a generally accepted statistical
technique such as Anderson-Darling (AD) or Shapiro-Wilk at the 0,01 significance level.
NOTE 2 PT data with insufficient resolution due to rounding can overestimate the normality
assessment statistics.
c) PT standard deviation is calculated using the root-mean-square technique.
d) z-scores are as defined in ISO 13528:2015, 9.4.
5 Comparison of PT precision achieved to published precision
5.1 General
The comparison of PT precision achieved to published precision is carried out via a formal
hypothesis test.
The parameter of interest is the standard deviation under reproducibility conditions as defined in
ISO 425
...
SLOVENSKI STANDARD
oSIST prEN ISO 4259-3:2019
01-februar-2019
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6SUHPOMDQMHLQXSUDYOMDQMHSRGDWNRYRQDWDQþQRVWLSULSUHVNXVQLKPHWRGDK
,62',6
Petroleum and related products - Precision of measurement methods and results - Part
3: Monitoring and management of precision data in relation to methods of test (ISO/DIS
4259-3:2018)
Mineralölerzeugnisse - Präzision von Messverfahren und Ergebnissen - Teil 3:
Monitoring und Management der Präzisionsdaten in Bezug auf Prüfverfahren (ISO/DIS
4259-3:2018)
Produits pétroliers - Fidélité des méthodes de mesure et des résultats - Partie 3 :
Surveillance et gestion des données de fidélité en relation avec les méthodes d'essai
(ISO/DIS 4259-3:2018)
Ta slovenski standard je istoveten z: prEN ISO 4259-3
ICS:
75.080 Naftni proizvodi na splošno Petroleum products in
general
75.180.30 Oprema za merjenje Volumetric equipment and
prostornine in merjenje measurements
oSIST prEN ISO 4259-3:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 4259-3:2019
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oSIST prEN ISO 4259-3:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 4259-3
ISO/TC 28 Secretariat: NEN
Voting begins on: Voting terminates on:
2018-12-03 2019-02-25
Petroleum and related products — Precision of
measurement methods and results —
Part 3:
Monitoring and verification of published precision data in
relation to methods of test
Produits pétroliers — Fidélité des méthodes de mesure et des résultats —
Partie 3: Surveillance et gestion des données de fidélité en relation avec les méthodes d'essai
ICS: 75.080
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 4259-3:2018(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2018
---------------------- Page: 3 ----------------------
oSIST prEN ISO 4259-3:2019
ISO/DIS 4259-3:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 4259-3:2019
ISO/DIS 4259-3:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Proficiency Testing scheme requirement . 2
4.1 General . 2
4.1.1 PT scheme provider . 2
4.1.2 PT homogeneity and stability of proficiency test items . 2
4.1.3 PT data and statistics requirement . 2
5 Comparison of PT precision achieved to published precision . 3
5.1 General . 3
5.2 Perform F-test on the variance ratio . 3
5.2.1 Construction of the variance ratio to be used for the F-test . 3
5.2.2 Comparison of variance ratio to be tested to a critical value F_crit_,025. 4
Annex A (informative) Worked examples of F-test . 7
Annex B (informative) Use of z scores to monitor an individual participant's PT performance .8
Bibliography .11
© ISO 2018 – All rights reserved iii
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oSIST prEN ISO 4259-3:2019
ISO/DIS 4259-3:2018(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 28, Petroleum products and related products of
synthetic or biological origin.
ISO 4259, Petroleum and related products — Precision of measurement methods and results ,consists
of the following parts:
— Part 1: Determination of precision data in relation to methods of test,
— Part 2: Interpretation and application of precision data in relation to methods of test, and
— Part 3: Monitoring and verification of published precision data in relation to methods of test.
th
A 4 part with the title "Use of Statistical Control Charts to validate 'in-statistical-control' status for the
execution of a standard test method in a single laboratory" is under development in ISO/TC 28/WG 2
iv © ISO 2018 – All rights reserved
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oSIST prEN ISO 4259-3:2019
ISO/DIS 4259-3:2018(E)
Introduction
For purposes of quality control and to check compliance with specifications, the properties of
commercial petroleum products are assessed by standard laboratory test methods. Two or more
measurements of the same property of a specific sample by a specific test method, or, by different test
methods that purport to measure the same property, will not usually give exactly the same result. It is,
therefore, necessary to take proper account of this fact, by arriving at statistically based estimates of
the precision for a method, i.e. an objective measure of the degree of agreement expected between two
or more results obtained in specified circumstances.
ISO 4259-1 specifies the methodology for the design, execution, and data processing of a one-
time snapshot statistical study to arrive at precision estimates achieved by a random sampling of
laboratories. This snapshot estimate is published in the standard test method as the expected precision.
This document specifies the methodology for utilisation of Proficiency Testing (PT) schemes (as defined
in ISO 4259-2) to test the hypothesis that the precision achieved by the laboratories in the PT scheme is
statistically consistent with the published precision derived from the ISO 4259-1 study described above.
© ISO 2018 – All rights reserved v
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oSIST prEN ISO 4259-3:2019
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oSIST prEN ISO 4259-3:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 4259-3:2018(E)
Petroleum and related products — Precision of
measurement methods and results —
Part 3:
Monitoring and verification of published precision data in
relation to methods of test
1 Scope
This International Standard specifies the methodology for the regular monitoring of the test method
precision achieved versus precision published in the standard test method using data from Proficiency
Testing (PT) schemes supported by the regular users of standard test methods.
The procedures in this International Standard are designed specifically for PTs' conducted on standard
test methods for petroleum and petroleum related products, which are presumed to be homogeneous
and where the data distribution is approximately normal.
The procedures in this document are designed specifically for standard test methods with published
[1]
reproducibility derived from ISO 4259-1 or equivalent (such as ASTM D6300 ) for petroleum and
petroleum related products, which are normally considered as homogeneous.
In particular, this document specifies the methodology for the statistical comparison of standard
deviation under reproducibility conditions achieved in PT programmes versus that published.
Purpose of this comparison is to ascertain if the published reproducibility precision is representative of
that achievable by the regular participants in the PT programmes.
Guidance on how to use PT zz score to monitor an individual participant's performance over time is
provided as an Informative Annex.
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 4259-1, Petroleum and related products — Precision of measurement methods and results — Part 1:
Determination of precision data in relation to methods of test
ISO 13528:2015, Statistical methods for use in proficiency testing by interlaboratory comparison
ISO/IEC 17043, Conformity assessment — General requirements for proficiency testing
3 Terms and definitions
For the purposes of this document, the terms and definitions in ISO 4259-1, ISO 13528 and ISO 17043
and the following 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/
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oSIST prEN ISO 4259-3:2019
ISO/DIS 4259-3:2018(E)
3.1
Proficiency Testing
PT
evaluation of participant performance against pre-established criteria by means of interlaboratory
comparisons
[SOURCE: adapted from ISO/IEC 17043]
3.2
Proficiency Testing Schemes
PTS
programme designed for the periodic evaluation of participating laboratories’ proficiency in the
execution of a Standard Test Method through the statistical analysis of their test results obtained on
aliquots prepared from a single batch of homogeneous material
Note 1 to entry: The frequency of such testing varies in accordance with the scheme objective. Each execution of
testing involves testing of a single batch of material. Materials typically vary from test to test.
Note 2 to entry: This is also commonly referred to as Inter Laboratory Cross Check Programme (ILCP).
4 Proficiency Testing scheme requirement
4.1 General
4.1.1 PT scheme provider
The proficiency testing (PT) scheme provider should conform to technical and management
requirement as outlined in ISO/IEC 17043.
4.1.2 PT homogeneity and stability of proficiency test items
4.1.2.1 Property stability
This standard is suitable only for properties of interest that are known to be stable over time and
transport.
4.1.2.2 Property homogeneity
The assessment of property homogeneity shall be performed after the proficiency test items have been
packaged in the final form and before distribution to participants. Consult and follow appropriate
guidance from ISO 13528, Annex B (Homogeneity and stability of proficiency test items).
4.1.3 PT data and statistics requirement
The comparison methodology in this document is intended for PT data and statistics meeting the
following requirement:
PT Data Requirement:
1) Data is obtained using a common standard test method with a published reproducibility obtained
in accordance with ISO 4259-1 or equivalent
2) Data is all numeric (i.e. does not contain censored results such as < xxx or > xxx)
3) A single result only is reported by each participant (i.e. no repeat)
PT Statistics
...
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