1、BSI Standards PublicationEnvironmental testingPart 2-78: Tests Test Cab: Damp heat, steady stateBS EN 60068-2-78:2013National forewordThis British Standard is the UK implementation of EN 60068-2-78:2013. It is identical to IEC 60068-2-78:2012. It supersedes BS EN 60068-2-78:2002, which will be withd
2、rawn on 3 December 2015.The UK participation in its preparation was entrusted to Technical Committee GEL/104, Environmental conditions, classification and testing.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to in
3、clude all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 72152 6ICS 19.040; 29.020Compliance with a British Standard cannot confer immunity from legal obligations.
4、This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60068-2-78:2013EUROPEAN STANDARD EN 60068-2-78 NORME EUROPENNE EUROPISCHE NORM June 2013 CENELE
5、C European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide
6、for CENELEC members. Ref. No. EN 60068-2-78:2013 E ICS 19.040; 29.020 Supersedes EN 60068-2-78:2001 English version Environmental testing - Part 2-78: Tests - Test Cab: Damp heat, steady state (IEC 60068-2-78:2012) Essais denvironnement - Partie 2-78: Essais - Essai Cab: Chaleur humide, essai contin
7、u (CEI 60068-2-78:2012) Umgebungseinflsse - Teil 2-78: Prfverfahren - Prfung Cab: Feuchte Wrme, konstant (IEC 60068-2-78:2012) This European Standard was approved by CENELEC on 2012-12-03. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions fo
8、r 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 CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in
9、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 CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national e
10、lectrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal,
11、 Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60068-2-78:2013EN 60068-2-78:2013 - 2 - Foreword The text of document 104/582/FDIS, future edition 2 of IEC 60068-2-78, prepared by IEC/TC 104 “Environmental conditions, classification, and methods of test
12、“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60068-2-78:2013. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2013-12-14 latest date by
13、which the national standards conflicting with the document have to be withdrawn (dow) 2015-12-03 This document supersedes EN 60068-2-78:2001. EN 60068-2-78:2013 includes the following significant technical changes with respect to EN 60068-2-78:2001: The test chamber from EN 60068-3-6 has been introd
14、uced. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60068-2-78:2012 wa
15、s approved by CENELEC as a European Standard without any modification. BS EN 60068-2-78:2013- 3 - EN 60068-2-78:2013 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively re
16、ferenced 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. NOTE When an international publication has been modified by common modi
17、fications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60068-1 - Environmental testing - Part 1: General and guidance EN 60068-1 - IEC 60068-3-6 - Environmental testing - Part 3-6: Supporting documentation and guidance - Confirmation of the performance of te
18、mperature/humidity chambers EN 60068-3-6 - IEC Guide 104 - The preparation of safety publications and the use of basic safety publications and group safety publications - - BS EN 60068-2-78:2013 2 60068-2-78 IEC:2012 CONTENTS INTRODUCTION . 5 1 Scope and object 6 2 Normative references . 6 3 Terms a
19、nd definitions . 6 4 General test procedure . 6 Test chamber and measuring system 6 4.1Severity . 7 4.2Pre-conditioning 7 4.3Testing procedure . 7 4.4Recovery procedure 8 4.55 Measurements 8 Initial measurements . 8 5.1Intermediate measurements 8 5.2Final measurements 8 5.36 Information to be given
20、in the relevant specification 8 7 Information to be given in the test report 9 Table 1 Temperature and relative humidity 7 BS EN 60068-2-78:201360068-2-78 IEC:2012 5 INTRODUCTION This part of IEC 60068 provides a test method of high humidity at constant temperature without condensation on the specim
21、en 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. BS EN 60068-2-78:2013 6 60068-2-78 IEC:2012 ENVIRONMENTAL TESTING Part 2-78: Tests Test Cab: Damp heat, steady state 1 Scope and object Th
22、is 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
23、 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 th
24、is 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, Environ
25、mental 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 tes
26、t procedure Test chamber and measuring system 4.1The 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 to monitor the temperature
27、and humidity, NOTE For heat-dissipating specimens, the temperature and humidity near the specimen may be influenced by the effect of heat dissipation from the specimen. condensed water is drained from the chamber and not re-used unless purified, no condensed water from the walls and roof of the test
28、 chamber can fall on the specimen(s), BS EN 60068-2-78:201360068-2-78 IEC:2012 7 water utilized to maintain humidity levels has electrical conductivity of not more than 20 S/cm, the specimen under test shall not be subjected to radiant heat from the chamber conditioning devices, injected moisture, w
29、hen applicable, is injected remotely from the specimen and without being directly on it, the volume of the test chamber is at least five times the total volume of the specimen under test, a mounting device, when used, has minimum influence on the heat and humidity exchanges between specimen and surr
30、ounding conditions, unless otherwise specified in the relevant specification. Severity 4.2The test severity is defined by a combination of temperature, relative humidity (RH) and total test duration. Unless otherwise specified in the relevant specification, temperature and RH severities may be selec
31、ted from the following: Table 1 Temperature and relative humidity Temperature C Relative humidity % RH 30 2 93 3 30 2 85 3 40 2 93 3 40 2 85 3 Preferred test durations are: 12 h, 16 h, 24 h; 2 days, 4 days, 10 days, 21 days or 56 days. The total temperature tolerance of 2 K is intended to take accou
32、nt of absolute errors in the measurement, slow changes of temperature and temperature variations of the working space. However, in order to maintain the RH within the required tolerances, it is necessary to keep the temperature difference between any two points in the working space at any moment wit
33、hin narrower limits. The required humidity conditions will not be achieved if such temperature differences exceed 1 K. It may also be necessary to keep short-term fluctuations within 0,5 K to maintain the required humidity. Pre-conditioning 4.3The relevant specification may call for pre-conditioning
34、. Testing procedure 4.4The specimen shall be introduced into the chamber as required by the relevant specification. The specimen shall be introduced in the unpacked, switched-off, ready-for-use state, or as otherwise specified in the relevant specification. In certain cases the relevant specificatio
35、n may allow the introduction of the specimen in the chamber when this is already in the condition prescribed for the test; however, condensation on the specimen shall always be avoided. This can be obtained for small specimens by pre-heating them to the chamber temperature. Adjust the temperature in
36、 the chamber to the prescribed severity. In order to avoid condensation on the specimen, control the specimen temperature or allow the specimen to reach the temperature first and then adjust the humidity in the chamber to the prescribed severity. BS EN 60068-2-78:2013 8 60068-2-78 IEC:2012 Adjust th
37、e humidity to the prescribed severity within a period of time of not more than 2 h. Expose the specimen to the test conditions and duration as specified in the relevant specification. The duration is measured from the time the specified conditions are achieved. The relevant specification shall defin
38、e the operating conditions and the period (or periods) in which they shall be carried out. After conditioning at the prescribed severity and before the final measurement, the recovery procedure shall be followed. Recovery procedure 4.5The relevant specification shall prescribe the recovery method an
39、d duration. Recovery conditions are described in IEC 60068-1. 5 Measurements Initial measurements 5.1The specimen shall be visually inspected and electrically and mechanically checked, as required by the relevant specification. Intermediate measurements 5.2The relevant specification may call for mea
40、surements during the test procedure while the specimen is still in the chamber. If such measurements are required, the relevant specification shall define the measurements and the period (periods) at which they shall be carried out. For these measurements, the specimen shall not be removed from the
41、chamber. Final measurements 5.3The specimen shall be visually inspected and electrically and mechanically checked, as required by the relevant specification. 6 Information to be given in the relevant specification The following details shall be given as far as they are applicable: a) preconditioning
42、; b) initial measurements; c) details of mounting or supports; d) state of specimen (unpowered, powered, packaged, unpackaged, etc.); e) type of specimen heat dissipating or non-heat dissipating; f) test severities and tolerances 1) temperature, 2) relative humidity, 3) duration; g) intermediate mea
43、surements; h) recovery conditions; i) final measurements; j) any deviation in procedure as agreed upon between customer and supplier. BS EN 60068-2-78:201360068-2-78 IEC:2012 9 7 Information to be given in the test report As a minimum, the test report shall contain the following information. Items s
44、hown in parentheses are examples. a) Customer (name and address) b) Test laboratory (name and address and details of accreditation if any) c) Test dates (dates when test was run) d) Type of test (Cab) e) Purpose of test (development, qualification, etc.) f) Test standard, edition (IEC 60068-2-78:edi
45、tion used) g) Relevant laboratory test procedure (code and object) h) Test specimen description (drawing, photo, quantity, build status, etc.). i) Test chamber identity (manufacturer, model number, unique identification, etc.) j) Performance of test apparatus (set point temperature control, air flow
46、, etc.) k) Uncertainties of measuring system (uncertainties data) l) Calibration data (last and next due date) m) Initial, intermediate and final measurements (initial, intermediate and final measurements) n) Required severities (from relevant specification) o) Actual test conditions (measurement lo
47、cation, data, etc.) p) Performance of test specimens (results of functional tests, etc.) q) Observations during testing and actions taken (any pertinent observations) r) Summary of test (test summary) s) Distribution (distribution list) _ BS EN 60068-2-78:2013This page deliberately left blankThis pa
48、ge deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related publications, information and services.BSI is incorporated by Royal Charter. British Standards and other standardization products are published by BSI Standards Limited.British
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