IEC 60493-1:2011

Guide for the statistical analysis of ageing test data - Part 1: Methods based on mean values of normally distributed test results

IEC 60493-1:2011 gives statistical methods which may be applied to the analysis and evaluation of the results of ageing tests. It covers numerical methods based on mean values of normally distributed test results. These methods are only valid under specific assumptions regarding the mathematical and physical laws obeyed by the test data. Statistical tests for the validity of some of these assumptions are also given. This standard deals with data from both complete test sets and censored test sets. This standard provides data treatment based on the concept of "data sub-group" as defined in Clause 3. The validity of the coefficients used in the calculation processes to derive statistical parameters of the data groups are described in IEC 60216-1. This second edition cancels and replaces the first edition, published in 1974, and constitutes a technical revision. The main changes with respect to the first edition are that, besides a complete editorial revision, censored data sub-group are considered.

Guide pour l'analyse statistique de données d'essais de vieillissement - Partie 1: Méthodes basées sur les valeurs moyennes de résultats d'essais normalement distribués

La CEI 60493-1:2011 décrit les méthodes statistiques qui peuvent être appliquées pour l'analyse et l'évaluation des résultats d'essais de vieillissement. Elle couvre les méthodes numériques fondées sur les valeurs moyennes de résultats d'essais normalement distribués. Ces méthodes ne sont valables qu'en formulant des hypothèses relatives aux lois mathématiques et physiques que suivent les résultats d'essais. Des essais statistiques permettant de vérifier la validité de quelques unes de ces hypothèses sont également donnés. La présente norme traite non seulement des données obtenues à partir d'ensembles d'essais complets mais également d'ensembles d'essais censurés. Cette norme propose un traitement des données fondé sur le concept de "sous-groupe de données" défini dans l'Article 3. La validité des coefficients utilisés dans les méthodes de calcul pour dériver les paramètres statistiques des groupes de données est décrite dans CEI 60216-1. Cette deuxième édition annule et remplace la première édition, publiée en 1974. Elle constitue une révision technique. Les principales modifications par rapport à la première édition comprennent, outre une révision éditoriale complète, une prise en compte de sous-groupes de données censurées.

General Information

• Status: Published
• Publication Date: 13-Dec-2011
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: TC 112 - Evaluation and qualification of electrical insulating materials and systems
• Drafting Committee: WG 7 - TC 112/WG 7
• Current Stage: PPUB - Publication issued
• Start Date: 15-Mar-2012
• Completion Date: 14-Dec-2011

Standards Content (Sample)

IEC 60493-1 ®
Edition 2.0 2011-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Guide for the statistical analysis of ageing test data –
Part 1: Methods based on mean values of normally distributed test results

Guide pour l’analyse statistique de données d’essais de vieillissement –
Partie 1: Méthodes basées sur les valeurs moyennes de résultats d’essais
normalement distribués
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or
IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: [e-mail]
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
 Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
 IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
 Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
 Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: [e-mail]
Tel.: [phone]
Fax: [phone]
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
 Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
 Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
 Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
 Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: [e-mail]
Tél.: [phone]
Fax: [phone]
IEC 60493-1 ®
Edition 2.0 2011-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Guide for the statistical analysis of ageing test data –
Part 1: Methods based on mean values of normally distributed test results

Guide pour l’analyse statistique de données d’essais de vieillissement –
Partie 1: Méthodes basées sur les valeurs moyennes de résultats d’essais
normalement distribués
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX V
ICS 29.035.01 ISBN 978-2-88912-834-1

– 2 – 60493-1  IEC:2011
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and symbols . 6
3.1 Terms and definitions . 6
3.2 Symbols . 8
4 Calculation procedures . 9
4.1 General considerations . 9
4.2 Single sub-group – Difference of mean and specified value . 9
4.2.1 General . 9
4.2.2 Complete data sub-group . 9
4.2.3 Censored data sub-group . 10
4.3 Two subgroups – Difference of means . 10
4.3.1 General . 10
4.3.2 Both sub-groups complete . 10
4.3.3 One or both subgroups censored . 11
4.4 Two or more subgroups – Analysis of variance . 11
4.5 Three or more subgroups – Regression analysis . 13
4.5.1 Regression analysis – General considerations . 13
4.5.2 Calculations. 14
4.5.3 Test equality of subgroup variances . 15
4.5.4 Test significance of deviations from linearity . 16
4.5.5 Estimate and confidence limit of y . 16
4.5.6 Estimate and confidence limit of x . 16
Annex A (informative) Statistical background . 18
Annex B (informative) Statistical tables . 22
Bibliography . 35

Table B.1 – Coefficients for censored data calculations . 23
Table B.2 – Fractiles of the F-distribution, F . 30
0,95
Table B.3 – Fractiles of the F-distribution, F . 32
0,995
Table B.4 – Fractiles of the t-distribution, t . 34
0,95
Table B.5 – Fractiles of the χ -distribution . 34

60493-1  IEC:2011 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
GUIDE FOR THE STATISTICAL ANALYSIS
OF AGEING TEST DATA –
Part 1: Methods based on mean values
of normally distributed test results

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60493-1 has been prepared by IEC technical committee 112:
Evaluation and qualification of electrical insulating materials and systems.
This second edition cancels and replaces the first edition, published in 1974, and constitutes
a technical revision.
The main changes with respect to the first edition are that, besides a complete editorial
revision, censored data sub-group are considered.

– 4 – 60493-1  IEC:2011
The text of this standard is based on the following documents:
CDV Report on voting
112/172/CDV 112/192/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 60493 series, published under the general title Guide for the
statistical analysis of ageing test data, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
60493-1  IEC:2011 – 5 –
INTRODUCTION
Procedures for estimating ageing properties are described in specific test procedures, or are
covered by the general documents on test procedures for ageing tests with a specific
environmental stress (e.g. temperature, radiation, partial discharges).
In many cases, a certain property is determined as a function of time at different ag
...