EN 60068-3-11:2007

SLOVENSKI STANDARD
01-oktober-2007
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Environmental testing -- Part 3-11: Supporting documentation and guidance - Calculation
of uncertainty of conditions in climatic test chambers
Umgebungseinflüsse - Teil 3-11: Unterstützende Dokumentation und Leitfaden -
Berechnung der Messunsicherheit von Umgebungsbedingungen in Klimaprüfkammern
Essais d'environnement - Partie 3-11: Documentation d’accompagnement et guide -
Calcul de l’incertitude des conditions en chambres d’essais climatiques
Ta slovenski standard je istoveten z: EN 60068-3-11:2007
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60068-3-11
NORME EUROPÉENNE
June 2007
EUROPÄISCHE NORM
ICS 19.040
English version
Environmental testing -
Part 3-11: Supporting documentation and guidance -
Calculation of uncertainty of conditions in climatic test chambers
(IEC 60068-3-11:2007)
Essais d'environnement -  Umgebungseinflüsse -
Partie 3-11: Documentation Teil 3-11: Unterstützende Dokumentation
d’accompagnement et guide - und Leitfaden -
Calcul de l’incertitude des conditions Berechnung der Messunsicherheit
en chambres d’essais climatiques von Umgebungsbedingungen
(CEI 60068-3-11:2007) in Klimaprüfkammern
(IEC 60068-3-11:2007)
This European Standard was approved by CENELEC on 2007-06-01. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60068-3-11:2007 E
Foreword
The text of document 104/409/FDIS, future edition 1 of IEC 60068-3-11, prepared by IEC TC 104,
Environmental conditions, classification and methods of test, was submitted to the IEC-CENELEC parallel
vote and was approved by CENELEC as EN 60068-3-11 on 2007-06-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-03-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-06-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60068-3-11:2007 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60068-3-11:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
1) 2)
IEC 60068-3-5 - Environmental testing - EN 60068-3-5 2002
Part 3-5: Supporting documentation and
guidance - Confirmation of the performance
of temperature chambers
1) 2)
IEC 60068-3-6 - Environmental testing - EN 60068-3-6 2002
Part 3-6: Supporting documentation and
guidance - Confirmation of the performance
of temperature/humidity chambers

ISO 3534-1 2006 Statistics - Vocabulary and symbols - - -
Part 1: General statistical terms and terms
used in probability
ISO 3534-2 2006 Statistics - Vocabulary and symbols - - -
Part 2: Applied statistics
ISO Guide 99 1996 International vocabulary of basic and general - -
terms in metrology
ISO/IEC Guide 98 1995 Guide to the expression of uncertainty in - -
measurement
1)
Undated reference.
2)
Valid edition at date of issue.

INTERNATIONAL IEC
STANDARD
CEI
60068-3-11
NORME
First edition
INTERNATIONALE
Première édition
2007-05
Environmental testing –
Part 3-11:
Supporting documentation and guidance –
Calculation of uncertainty of conditions
in climatic test chambers
Essais d’environnement –
Partie 3-11:
Documentation d’accompagnement et guide –
Calcul de l’incertitude des conditions
en chambres d’essais climatiques
PRICE CODE
V
CODE PRIX
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
Pour prix, voir catalogue en vigueur

– 2 – 60068-3-11 © IEC:2007
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.7
2 Normative references .7
3 Terms and definitions .8
4 Concept of uncertainty.11
4.1 Uncertainty, error and “true value”.11
4.2 Statements of uncertainty.12
4.3 Combining uncertainties .13
5 Tolerance .13
6 Humidity and temperature measurement .13
7 Methods for determining climatic test chamber uncertainties .14
7.1 Empty chamber .16
7.2 Typical load.16
7.3 Measurement of conditions in the chamber during the test .17
7.4 Conditions to measure.17
7.5 Measurements required.18
7.6 Sources of uncertainty.19
7.7 Essential contributions of uncertainty .20
8 Estimation of uncertainty components and their combination .24
9 Overall uncertainty of temperature measurement.24
9.1 General .24
9.2 Further considerations.26
10 Overall uncertainty of relative humidity measurement .26
10.1 Uncertainty of temperature measurement at each sensor point.27
10.2 Uncertainty of the relative humidity measurement.27
11 Anomalous data and presentation of results .30
11.1 Average case analysis.30
11.2 Worst case analysis .30

Annex A (informative) Measurement data sets – Loaded chamber .32

Bibliography.34

60068-3-11 © IEC:2007 – 3 –
Figure 1 – Approaches to calibration method and uncertainty calculation.15
Figure 2 – Illustration of the fluctuation of a temperature sensor .23

Table 1 – Combination of temperature uncertainties .24
Table 2 – Combination of temperature uncertainties at each point .27
Table 3 – Combination of humidity uncertainties .28
Table A.1 – Typical temperature measurement data set and it’s analysis and refs .32
Table A.2 – Humidity measurements analysis based on Table A.1 temperatures.33

– 4 – 60068-3-11 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 3-11: Supporting documentation and guidance –
Calculation of uncertainty of conditions in climatic test chambers

FOREWORD
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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 60068-3-11 has been prepared by IEC technical committee 104:
Environmental conditions, classification and methods of test.
The text of this standard is based on the following documents:
FDIS Report on voting
104/409/FDIS 104/415/RVD
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.

60068-3-11 © IEC:2007 – 5 –
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