IEC 60068-2-78:2012

IEC 60068-2-78 ®
Edition 2.0 2012-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Environmental testing –
Part 2-78: Tests – Test Cab: Damp heat, steady state

Essais d’environnement –
Partie 2-78: Essais – Essai Cab: Chaleur humide, essai continu

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IEC 60068-2-78 ®
Edition 2.0 2012-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ

Environmental testing –
Part 2-78: Tests – Test Cab: Damp heat, steady state

Essais d’environnement –
Partie 2-78: Essais – Essai Cab: Chaleur humide, essai continu

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX J
ICS 19.040; 29.020 ISBN 978-2-83220-444-3

– 2 – 60068-2-78  IEC:2012
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope and object . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General test procedure . 6
4.1 Test chamber and measuring system . 6
4.2 Severity . 7
4.3 Pre-conditioning . 7
4.4 Testing procedure . 7
4.5 Recovery procedure . 8
5 Measurements . 8
5.1 Initial measurements . 8
5.2 Intermediate measurements . 8
5.3 Final measurements . 8
6 Information to be given in the relevant specification. 8
7 Information to be given in the test report . 9

Table 1 – Temperature and relative humidity . 7

60068-2-78  IEC:2012 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-78: Tests – Test Cab: Damp heat, steady state

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
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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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 60068-2-78 has been prepared by technical committee 104:
Environmental conditions, classification, and methods of test.
This second edition cancels and replaced the first edition, published in 2001 and constitutes a
technical revision.
This edition includes editorial and format changes with respect to the previous edition:
– The test chamber from IEC 60068-3-6 has been introduced.

– 4 – 60068-2-78  IEC:2012
The text of this standard is based on the following documents:
FDIS Report on voting
104/582/FDIS 104/588/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.
It has the status of a basic safety publication in accordance with IEC Guide 104.
A list of all the parts in the IEC 60068 series, under the general title Environmental testing,
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.
60068-2-78  IEC:2012 – 5 –
INTRODUCTION
This part of IEC 60068 provides a test method of high humidity at constant temperature
without condensation on the specimen over a prescribed period. This test is performed to
evaluate the specimen as it is influenced by the absorption and diffusion of moisture and
moisture vapour.
– 6 – 60068-2-78  IEC:2012
ENVIRONMENTAL TESTING –
Part 2-78: Tests – Test Cab: Damp heat, steady state

1 Scope and object
This part of IEC 60068 establishes a test method for determining the ability of components or
equipment to withstand transportation, storage and use under conditions of high humidity.
The object of this standard is to investigate the effect of high humidity at constant temperature
without condensation on a specimen over a prescribed period.
It is applicable to small equipment or components as well as large equipment, and can be
applied to both heat-dissipating and non-heat-dissipating specimens.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-1, Environmental testing – Part 1:General and guidance
IEC 60068-3-6, Environmental testing – Part 3-6: Supporting documentation and guidance –
Confirmation of the performance of temperature and humidity chambers
IEC Guide 104, The preparation of safety publications and the use of basic safety publications
and group safety publications
3 Terms and definitions
None.
4 General test procedure
4.1 Test chamber and measuring system
The temperature and humidity chamber shall be constructed and verified in accordance with
specifications IEC 60068-3-6.
The chamber and measuring system shall be such that
– sensing devices can be located in the working space t
...