EN 60068-2-78-2001 en Environmental Testing Part 2-78 Tests - Test Cab Damp Heat Steady State (Remains Current)《环境试验 第2-78部分 试验 试验Cab 稳态湿热 IEC 60068-2-78-2001》.pdf

1、BRITISH STANDARDBS EN 60068-2-78: 2002IEC 60068-2-78: 2001Environmental testing Part 2-78: Tests Test Cab: Damp heat, steady stateThe European Standard EN 60068-2-78:2001 has the status of a British StandardICS 19.040; 19.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWIncor

2、porating Corrigendum No. 1BS EN 60068-2-78:2002This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 13 March 2002ISBN 0 580 39095 0National for

3、ewordThe UK participation in its preparation was entrusted to Technical Committee GEL/104, Environmental conditions, classification, and testing, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. aid enquirers to under

4、stand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a fr

5、ont cover, an inside front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover.The BSI copyright date displayed in this document indicates when the document was last issued.This British Standard is the official English language version of EN 60068-2-78:2001. It is identical

6、 with IEC 60068-2-78:2001. It supersedes BS 2011-2.1Ca:1977 and BS 2011-2.1Cb:1990 which are withdrawn. BSI 2006Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “Inte

7、rnational Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a Br

8、itish Standard does not of itself confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date Comments15891 Corrigendum No. 129 December 2006 Addition of supersession detailsEUROPEAN STANDARD EN 60068-2-78NORME EUROPENNEEUROPISCHE NORM October 2001CENELECEuropean Committe

9、e for Electrotechnical StandardizationComit Europen de Normalisation ElectrotechniqueEuropisches Komitee fr Elektrotechnische NormungCentral Secretariat: rue de Stassart 35, B - 1050 Brussels CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.Ref

10、. No. EN 60068-2-78:2001 EICS 19.040; 29.020English versionEnvironmental testingPart 2-78: Tests -Test Cab: Damp heat, steady state(IEC 60068-2-78:2001)Essais denvironnementPartie 2-78: Essais -Essai Cab: Chaleur humide, essai continu(CEI 60068-2-78:2001)UmweltprfungenTeil 2-78: Prfungen -Prfung Cab

11、: Feuchte Wrme, konstant(IEC 60068-2-78:2001)This European Standard was approved by CENELEC on 2001-10-01. CENELEC members are bound tocomply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any altera

12、tion.Up-to-date lists and bibliographical references concerning such national standards may be obtained onapplication to the Central Secretariat or to any CENELEC member.This European Standard exists in three official versions (English, French, German). A version in any otherlanguage made by transla

13、tion under the responsibility of a CENELEC member into its own language andnotified to the Central Secretariat has the same status as the official versions.CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,Denmark, Finland, France, Germany, Greece, Icel

14、and, Ireland, Italy, Luxembourg, Malta, Netherlands,Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EN 60068-2-78:2001 - 2 -ForewordThe text of document 104/207/FDIS, future edition 1 of IEC 60068-2-78, prepared by IEC TC 104,Environmental conditions, classification and methods of te

15、st, was submitted to the IEC-CENELECparallel vote and was approved by CENELEC as EN 60068-2-78 on 2001-10-01.The following dates were fixed: latest date by which the EN has to be implementedat national level by publication of an identicalnational standard or by endorsement (dop) 2002-07-01 latest da

16、te by which the national standards conflictingwith the EN have to be withdrawn (dow) 2004-10-01Annexes designated “normative“ are part of the body of the standard.Annexes designated “informative“ are given for information only.In this standard, annex ZA is normative.Annex ZA has been added by CENELE

17、C._Endorsement noticeThe text of the International Standard IEC 60068-2-78:2001 was approved by CENELEC as aEuropean Standard without any modification._Page 2EN 60068278:2001 BSI 200660068-2-78 IEC:2001 3 ENVIRONMENTAL TESTING Part 2-78: Tests Test Cab: Damp heat, steady state1 ScopeThis part of IEC

18、 60068 provides a test method for determining the suitability of electrotechnicalproducts, components or equipment for transportation, storage and use under conditions ofhigh humidity. The test is primarily intended to permit the observation of the effect of highhumidity at constant temperature with

19、out condensation on the specimen over a prescribedperiod.This test provides a number of preferred severities of high temperature, high humidity and testduration. The test can be applied to both heat-dissipating and non-heat dissipating specimens.The test is applicable to small equipment or component

20、s as well as large equipment havingcomplex interconnections with test equipment external to the chamber, requiring a set-up timewhich prevents the use of preheating and the maintenance of specified conditions during theinstallation period.2 Normative referencesThe following normative documents conta

21、in provisions which, through reference in this text,constitute provisions of this part of IEC 60068. For dated references, subsequent amendmentsto, or revisions of, any of these publications do not apply. However parties to agreementsbased on this part of IEC 60068 are encouraged to investigate the

22、possibility of applying themost recent editions of the normative documents indicated below. For undated references, thelatest edition of the normative document referred to applies. Members of ISO and IEC maintainregisters of currently valid International Standards.IEC 60068-1, Environmental testing

23、Part 1: General and guidanceIEC 60068-2-2, Basic environmental testing procedures Part 2: Tests Tests B: Dry heat3 General descriptionIn this test, the specimen is introduced into the chamber, both of which are at laboratorytemperature.The conditions in the chamber are adjusted to the severity requi

24、red according to clause 5 andmaintained for the prescribed time.Because the conditions of temperature and humidity adjacent to a heat-dissipating specimencan be different from the specified test values, the measurement of these parameters isprescribed in the manner used for free air conditions (see

25、4.4 and 4.6.2 of IEC 60068-1).Page 3EN 60068278:2001 BSI 200660068-2-78 IEC:2001 4 4 Test chamberThe chamber and measuring system shall be such that:a) sensing devices can be located in the working space to monitor the temperature andhumidity. For the testing of heat dissipating specimens, the devic

26、es are located at positionsas defined in IEC 60068-1;b) the temperature and relative humidity in the working space can be maintained at the valuesand within the tolerances prescribed, taking into account the effect of the specimen undertest on chamber conditions. The temperature tolerances given in

27、clause 5 are intended totake account of absolute errors in measurements and slow changes of temperature.For heat-dissipating specimens, the temperature and relative humidity near the specimenare influenced by the effect of heat-dissipation of the specimen itself and can be differentfrom the values m

28、easured in the positions defined in IEC 60068-1;c) condensed water is continuously drained from the chamber and not re-used until re-purified;d) no condensed water from the walls and roof of the test chamber can fall on the specimens;e) water utilized for the maintenance of chamber humidity shall ha

29、ve a resistivity of not lessthan 0,05 MG57cm;f) the specimen under test shall not be subjected to radiant heat from the chamberconditioning devices;g) in injection-type chambers, moisture shall be injected remotely from the specimen andwithout impinging directly on it.4.1 Testing of heat-dissipating

30、 specimensThe volume of the test chamber shall be at least five times the total volume of the specimenunder test.The distance between the specimen and the chamber walls shall be in accordance withappendix A of IEC 60068-2-2. The air speed within the chamber shall be commensurate withachieving the de

31、sired conditions.4.2 Mounting of the specimensThe relevant specification shall prescribe specific mounting structures, which shall replicate orsimulate the thermal characteristics applicable in real life conditions. If these conditions are notdefined, the mounting device shall have the minimum influ

32、ence on the heat and humidityexchanges between specimen and surrounding conditions.Page 4EN 60068278:2001 BSI 200660068-2-78 IEC:2001 5 5 SeverityThe test severity is defined by a combination of temperature, relative humidity and total testduration.Unless otherwise specified in the relevant specific

33、ation, temperature and relative humidityseverities may be selected from the following:(30 2) C (93 3) % RH(30 2) C (85 3) % RH(40 2) C (93 3) % RH(40 2) C (85 3) % RHPreferred test durations are: 12 h; 16 h; 24 h; and 2, 4, 10, 21 or 56 days.The total temperature tolerance of Gb12 K is intended to t

34、ake account of absolute errors in themeasurement, slow changes of temperature, and temperature variations of the working space.However, in order to maintain the relative humidity within the required tolerances, it isnecessary to keep the temperature difference between any two points in the working s

35、pace atany moment within narrower limits. The required humidity conditions will not be achieved ifsuch temperature differences exceed 1 K. It may also be necessary to keep short termfluctuations within Gb10,5 K to maintain the required humidity.6 Initial measurementsThe specimen shall be visually in

36、spected and electrically and mechanically checked, asrequired by the relevant specification.7 ConditioningThe conditioning shall be such that:a) Unless otherwise specified, the specimen shall be introduced into the chamber, both ofwhich shall be at standard ambient conditions of the laboratory. The

37、specimen shall beintroduced in the unpacked, switched-off, ready-for-use state.In certain cases the relevant specification may allow the introduction of the specimen in thechamber when this is already at the conditions prescribed for the test; however,condensation on the specimen shall always be avo

38、ided. This can be obtained for smallspecimens by pre-heating them to the chamber temperature.b) Adjust the temperature in the chamber to the prescribed severity, and allow the specimento reach temperature stability.Temperature stability is defined in 4.8 of IEC 60068-1. The rate of change of tempera

39、tureshall not exceed 1 K/min, averaged over a period of not more than 5 min. During thisperiod condensation on the specimen shall not occur.Page 5EN 60068278:2001 BSI 200660068-2-78 IEC:2001 6 c) Condensation can be avoided during this period by not increasing the absolute humidity.d) Adjust the hum

40、idity to the prescribed severity within a time of not more than 2 h.e) Expose the specimen to the test conditions and duration as specified in the relevantspecification. The duration is measured from the time the specified conditions areachieved.f) The relevant specification shall define the operati

41、ng conditions and the period (or periods)in which they shall be carried out.g) At the end the recovery procedure shall be followed.8 Intermediate measurementsThe relevant specification may call for measurements during, or at the end of, conditioningwhile the specimen is still in the chamber. If such

42、 measurements are required, the relevantspecification shall define the measurements and the period (or periods) at which they shall becarried out. For these measurements the specimen shall not be removed from the chamber.9 RecoveryThe relevant specification shall prescribe whether recovery shall be

43、made at standardatmospheric conditions for testing (see 5.3 of IEC 60068-1), or at controlled recoveryconditions (see 5.4.1 of IEC 60068-1). If controlled recovery conditions are required, thespecimen may be transferred to a second chamber for this recovery period or may remain inthe test chamber.If

44、 the second chamber method is used, the changeover time shall be as short as possible.Relative humidity shall be adjusted to a value of 73 % to 77 % RH in not more than 0,5 h, afterwhich the temperature shall be adjusted to laboratory temperature within Gb11 K in not morethan 0,5 h.The recovery time

45、 if specified in the relevant specification is counted from the moment whenthe prescribed recovery conditions have been obtained.10 Final measurementsThe specimen shall be visually inspected and electrically and mechanically checked, asrequired by the relevant specification.Page 6EN 60068278:2001 BS

46、I 200660068-2-78 IEC:2001 7 11 Information to be given in the relevant specificationWhen this test is included in the relevant specification, the following details shall be given asfar as they are applicable.Information to be given: Clause or subclausea) Specific mounting structures, if required 4.2

47、b) Test severities and tolerances: temperature relative humidity duration5c) Initial measurements 6d) Conditioning 7e) Intermediate measurements 8f) Recovery conditions 9g) Final measurements 10_Page 7EN 60068278:2001 BSI 2006- 3 - EN 60068-2-78:2001Annex ZA(normative)Normative references to interna

48、tional publicationswith their corresponding European publicationsThis European Standard incorporates, by dated or undated reference, provisions from otherpublications. These normative references are cited at the appropriate places in the text and thepublications are listed hereafter. For dated refer

49、ences, subsequent amendments to or revisions of anyof these publications apply to this European Standard only when incorporated in it by amendment orrevision. For undated references, the latest edition of the publication referred to applies (includingamendments).NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevantEN/HD applies.Publication Year Title EN/HD YearIEC 60068-1 - 1)Environmental testingPart 1: Genera