1、利小COMMISSION ELECTROTECHNIQUE INTERNATIONALE(alfiea Oganisation Internationaled Normalisation.1SO)RECOMMANDATION DE LA CEIINTERNATIONAL ELECT ROTECH NICAL COMMISSION(affiliated to the internalional Organizalon for Standardizalion-IS0)2IEC RECOMMENDATIONPublication 68-2-3Troisieme edition Third editi
2、on1969Essais fondamentaux climatiques et de robustesse mecaniqueDeuxieme partie:Essais-Essai Ca:Essal continu de chaleur humideBasic environmental testing proceduresPart 2:Tests-Test Ca:Damp heat,steady state拔中餐单Droits de reproctionrservs-Copyright-all righis feserved斋局Bureau Central de la Commissio
3、n Electrotechnique InternationaleI.ue de VarembeGeneve,Suisse73.7.26.1017CE-IA3INTERNATIONAL ELECTROTECHNICAL COMMISSIONBASIC ENVIRONMENTAL TESTING PROCEDURESPart 2:Tests-Test Ca:Damp heat,steady stateFOREWORD1)The formal decisions or agreements of the 1E Con technical matters,prepared by Technical
4、Committees on which all theNational Committees having a special interest therein are represented,express,as nearly as possible,an internatonalconsensus of opinion on the subjects dealt with.2)They have the form of recommendations for international use and they are accepted by the National Commiftees
5、 in thatsensc.3)Inorder to promote this international unification,the IEC expresses the wish that all National Committees having asyet no national rules,when preparing such rules,should use the I EC recommendations as the fundamental hasis for theserules in so far as national conditions will permit.
6、4)The desirability is recognized of extending international agreement on these matters through an endeavour to harmonizenational standardization rules with these recommendations in so far as natuonal conditions will permit.The NationalCommittees pledge their influence towards that end.PREFACEThis Re
7、commendation has been prepared by Sub-Committee 50B,Climatic Tests,of IEC TechnicalCommittee No.50,Environmental Testing.It replaces Test C.Damp Heat(Long Term Exposre),second edition(1960).The onlymajor differenc.rom Test C is the deletion of severity VII:four days plus assisted drying.A first draf
8、t was discussed at the meeting held in London in 1966.as a result of which,a new draftwas submitted to the National Committees for approval under the Six Months Rule in July 1967.The following countries voted explicitly in favour of publication:AustraliaKorea(Democratic Peoples Republic of).AustriaN
9、etherlandsBelgiumNorwayCzcchoslovakiaSouth AfricaDenmarkSwedenFranceSwitzerlandGermanyTurkeyHungaryUnion of Soviet Socialist RepublicsIsraelUnited KingdomItalyUnited States of AmericaJapanThis Recommendation should be used in conjunction with IEC Publication 68-1,Basic EnvironmentalTesting Procedure
10、s,Part 1:General.Reference is made to:IEC Publication 260,Test Enclosures of Non-injection Type for Constant Rclative Humidity.and to:IEC Publication 68-2-28.Basic Environmental Testing Procedures,Part 2:Tests-Guidance for DampHeat Tests.收文75.2.16CE-JABASIC ENVIRONMENTAL TESTING PROCEDURESPart 2:Tes
11、ts-Test Ca:Damp heat,steady stateObjectTo determine the suitability of components.cquipment or other articles for use and storage.under conditions of high relative humidity.This test is primarily intended to permit the observation of the cffects of high humidity atconstant temperature over a prescri
12、bed period.3Testing chamber2.1The chamber shall be so constructed that:1)The temperature and humidity of the chamber are monitored by sensing devices located in theworking space.2)The temperature and relative humidity in the working space can he maintained at 40:2 Cand 93%respectively.-Note.-The tem
13、perature tolerance of:2 deg C isintended to ta:e account ofabsolute errors in the meatsuren:e.slow changes of temperature,and temperature variations of the working space.It is neces.ry tokeep the short term temperature fuctuation within:0.5 deg(to maintair the required hum:du.3)Condensed water is co
14、ntinuously drained from the chamber and not used again until it hasbcen re-purified.4)When the humidity conditions are obtained by using an injection-type chamber.the water shallhave a resistivity not less than 500 2m.2.2Precautions shall-be taken to ensure that:1)The conditions prevailing throughou
15、t the working space are uniform and as similar aspossible to those prevailing in the immediate vicinity of the monitoring devices.2)The propertics or loading of the specimen under test do not appreciably influence conditionswithin the chamber.No condensed water from the walls and roof of the test ch
16、amber can fall on the specimens.3.Testing procedureInitial mcasurementsThe specimen shall be visually inspected and eiectrically and mechanically checked,a reiredby the relevant snecification.收文102275216CE-IA-3.2 Conditioning3.2.1 The specimen shall be introduced into the chamber in the state specif
17、ied in the relevant speci-fication.At the time of introducing the specimen into the chamber,care shall be taken to avoid theformation of water droplets on the specimen.This can be done by pre-heating the specimen to thechamber temperature.3.2.2 The specimen shall be introduced into the chamber and s
18、ubjected to one of the following severities,as required by the relevant specification:4 days10 days21 days56 daysNore.-The severity VII(four days plus assisted drying)as laid down in the second edition(1960)of IF:(Publi-Cation 68-2-3 has been deleted.Assisted drying can be obtained by preseribing an
19、 appropriate recovery condi-lion(sce Sub-clause 4.4).3.2.3 The relevant specification may call for loading and/or measurements during,or at the end of.conditioning while the specimen is still in the chamber.If such measurements are required,the relevant specification shall define the measurements an
20、dthe period or periods after which they shall be carried out.For these measurements;the specimenshall not be removed from the chamber.Note.-Measurements preceded by recovery,which would require removal of the specimens from the chamber,arenot permissible during the conditioning.If it is desired to k
21、now the performance of the type of specimen before the end of the prescribed duration,one additional lot will be required for each specified duration.Kccovery and final measurements shall be performed separately for each lot.4.Recovery4.1 At the end of the conditioning,the specimen shall be subjecte
22、d to standard atmospheric conditionsfor recovery for not less than 1 h and not more than 2 h.4.2 The specimen may be transferred to another chamber for recovery or may remain in the damp heatchamber depending upon the nature of the specimen and/or the capability of the testing laboratory.In the form
23、er case,the change-over time shall be as short as possible and shall not exceed 5 min.In the latter case,the relative humidity shall be reduced to between 73%and 77%r.h.in not morethan h,after which the temperature shall be adjusted to within!I deg Cofthe laboratory tem-perature innot more than h.4.
24、3 The relevant specification shall state whether any special precautions shall be taken regardingremoval of surface moisture.4.4 If the standard conditions given above are not appropriate for the specimen to be tested,therelevant specification may call for other recovery conditions.5.Final measureme
25、ntsThe specimen shall be visually inspected and electrically and mechanically checked,as req:iredby the relevant specification.1024收文0216家*六不林The measurements shall be commenced immediatcly after the recovery period and the para-meters most sensitive to changes of relative hiumidity shall he measure
26、d first.Unless otherwisespecified.the measurement of these parameters shall be completed within 30 min.6Information required in the relevant specificationWhen this test is included in the relevant.specification,the following details shall he given asfar as they are applicablc:Clauseorsuh-clauseaPrec
27、onditioning procedureb)Electrical and mechanical checks to be made prior to the test3.1State of the specimen as introduced into the chamber3.2.1dSeverity:numher of days3.2.2e)Loading during conditioning3.2.3Electrical and mechanical checks to be made during conditioning and theperiod(s)after which t
28、hey shall he performed3.2.3g)Special precautions to he taken regarding removal of surface moisture4.3h)F.covery conditions-if other than standard4.4Electrical and mechanical checks to he made at the end of the test,the para-meters to be measured first.and the maximum period allowed for themeasurement of these parameters收文102675,2.16
