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IEC 60068-2-38
Edition 3.0 2021-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Environmental testing –
Part 2-38: Tests – Test Z/AD: Composite temperature/humidity cyclic test
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IEC 60068-2-38
Edition 3.0 2021-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Environmental testing –
Part 2-38: Tests – Test Z/AD: Composite temperature/humidity cyclic test
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 19.040 ISBN 978-2-8322-9633-2
– 2 – IEC 60068-2-38:2021 RLV © IEC 2021
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General . 7
4.1 Description of the test . 7
4.2 Application of the test . 7
5 Description of test chamber . 8
5.1 General . 8
5.2 Chamber for exposure to moisture . 8
5.3 Chamber for exposure to cold . 9
6 Severities . 9
7 Testing procedure . 9
7.1 Preconditioning . 9
7.2 Initial measurements . 10
7.3 Conditioning . 10
7.4 Test cycle . 13
7.4.1 Description of temperature/humidity subcycle . 13
7.4.2 Description of cold subcycle . 14
7.4.3 Description of 24 h cycles with no exposure to cold . 15
7.4.4 Description of final cycle . 15
7.4.5 Intermediate measurements. 15
7.5 Final measurements . 17
7.5.1 Introductory remarks . 17
7.5.2 At high humidity . 18
7.5.3 Immediately upon removal from the chamber . 18
7.5.4 After final drying . 18
8 Information to be given in the relevant specification . 18
9 Information to be given in the test report. 19
Annex A (informative) Supporting documentation for test sequence . 21
A.1 General . 21
A.2 Preconditioning . 21
A.3 Exposure to humidity followed by exposure to cold . 22
A.4 Exposure to humidity not followed by exposure to cold. 23
Bibliography . 24
Figure 1 – Preconditioning . 10
Figure 2 – Exposure to humidity followed by exposure to cold. 12
Figure 3 – Exposure to humidity not followed by exposure to cold . 13
Figure 4 – Test times for intermediate operation of specimen – Exposure to humidity
followed by exposure to cold . 16
Figure 5 – Test times for intermediate operation of specimen – Exposure to humidity
not followed by exposure to cold . 17
Table A.1 – Relative humidity tolerances . 21
Table A.2 – Temperature tolerances . 21
Table A.3 – Tolerances of relative humidity and temperature during exposure to
humidity followed by exposure to cold . 22
Table A.4 – Tolerances of relative humidity and temperature during exposure to
humidity not followed by exposure to cold . 23
– 4 – IEC 60068-2-38:2021 RLV © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-38: Tests –
Test Z/AD: Composite temperature/humidity cyclic test
FOREWORD
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This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC 60068-2-38:2009. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.
IEC 60068-2-38 has been prepared by IEC technical committee 104: Environmental conditions,
classification and methods of test. It is an International Standard.
This third edition cancels and replaces the second edition, published in 2009. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the figures have been updated;
b) changes to the wording has been made for clarification purposes.
The text of this International Standard is based on the following documents:
Draft Report on voting
104/891/FDIS 104/896/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at /members_experts/refdocs. The main document types developed by IEC are
described in greater detail at /standardsdev/publications.
A list of all parts in the IEC 60068 series, published under the general title Environmental testing,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.
– 6 – IEC 60068-2-38:2021 RLV © IEC 2021
ENVIRONMENTAL TESTING –
Part 2-38: Tests –
Test Z/AD: Composite temperature/humidity cyclic test
1 Scope
This part of IEC 60068
...