EN 60068-3-11:2007

Environmental testing - Part 3-11: Supporting documentation and guidance - Calculation of uncertainty of conditions in climatic test chambers

Demonstrates how to estimate the uncertainty of steady-state temperature and humidity conditions in temperature and humidity chambers. Since this is inextricably linked to the methods of measurement, these are also described. This standard is equally applicable to all environmental enclosures, including rooms or laboratories. The methods used apply both to temperature chambers and combined temperature and humidity chambers. This standard is meant to help everyone using climatic test chambers. Those already familiar with uncertainty of measurement will find it useful for guidance on typical sources of uncertainty and how they should be quantified and combined. It is also intended to assist the first-time or occasional user who has little or no knowledge of the subject. To discuss uncertainty, it is important first to understand what is being measured or characterized. The calibration or characterization of the performance of a chamber is concerned with the humidity and temperature of the air in the chamber, as experienced by the item under test, at a given set point. This should not be confused with characterizing or calibrating the chamber sensor, which is a separate matter.

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

Montre comment estimer l'incertitude des conditions de température et d'humidité à l'état stable dans une chambre d'essais de température et d'humidité. Sachant que cela est inextricablement lié aux méthodes de mesures, celles-ci sont également décrites. La présente norme est également applicable à tout type d'enceintes d'environnement, et même les salles ou laboratoires. Les méthodes sont usuellement appliquées aux chambres d'essais régulées en température et aux chambres d'essais régulées en température et humidité. La présente norme cherche à aider toute personne utilisant des chambres d'essais climatiques. Les personnes étant déjà familières avec l'incertitude de mesure la trouveront utile pour les conseils sur les composantes types d'incertitudes et sur la manière dont il convient de les quantifier et de les combiner. Elle est également destinée à aider le nouvel utilisateur ou l'utilisateur occasionnel qui n'a qu'une faible connaissance du sujet ou pas de connaissance du tout. Afin d'aborder les incertitudes il est important tout d'abord de comprendre ce qui est mesuré ou caractérisé. L'étalonnage ou la caractérisation de la performance d'une chambre d'essais fait appel à la détermination de l'humidité et de la température de l'air de la chambre, vu par l'objet en essai, à une valeur de consigne donnée. Il convient que cela ne soit pas confondu avec le calibrage ou l'étalonnage du capteur de la chambre d'essai, qui est une opération différente.

Okoljski preskusi - 3-11.del: Spremljajoča dokumentacija in vodila - Izračunavanje nezanesljivosti pogojev v komorah za klimatsko preskušanje (IEC 60068-3-11:2007)

General Information

• Status: Published
• Publication Date: 27-Jun-2007
• Withdrawal Date: 31-May-2010
• ICS: 19.040 - Environmental testing
• Technical Committee: CLC/SR 104 - Environmental conditions, classification and methods of test
• Drafting Committee: IEC/TC 104 - IEC_TC_104
• Parallel Committee: IEC/TC 104 - IEC_TC_104
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 28-Jun-2007
• Completion Date: 28-Jun-2007
• Ref Project: SIST EN 60068-3-11:2007 - Environmental testing -- Part 3-11: Supporting documentation and guidance - Calculation of uncertainty of conditions in climatic test chambers

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2007
2NROMVNLSUHVNXVLGHO6SUHPOMDMRþDGRNXPHQWDFLMDLQYRGLOD,]UDþXQDYDQMH
QH]DQHVOMLYRVWLSRJRMHYYNRPRUDK]DNOLPDWVNRSUHVNXãDQMH,(&

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
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 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 –
A list of all parts in the IEC 60068 series, under th
...