BS EN 60068-2-1-2007 Environmental testing - Tests - Test A Cold《环境测试 试验 试验A 低温》.pdf

1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58The European Standard EN 60068-2-1:2007 has the status of a British StandardICS 19.040Environmental

2、 testing Part 2-1: Tests Test A: ColdBRITISH STANDARDBS EN 60068-2-1:2007BS EN 60068-2-1:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2007 BSI 2007ISBN 978 0 580 50804 2Amendments issued since publicationAmd. No. Date CommentsTh

3、is publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implemen

4、tation of EN 60068-2-1:2007. It is identical with IEC 60068-2-1:2007. It supersedes BS EN 60068-2.1:1993 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee GEL/104, Environmental conditions, classification and testing.A list of organizations represented

5、on this committee can be obtained on request to its secretary.EUROPEAN STANDARD EN 60068-2-1 NORME EUROPENNE EUROPISCHE NORM April 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Cen

6、tral Secretariat: rue de Stassart 35, B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60068-2-1:2007 E ICS 19.040 Supersedes EN 60068-2-1:1993 + A1:1993 + A2:1994English version Environmental testing - Part

7、2-1: Tests - Test A: Cold (IEC 60068-2-1:2007) Essais denvironnement - Partie 2-1: Essais - Essai A: Froid (CEI 60068-2-1:2007) Umgebungseinflsse - Teil 2-1: Prfverfahren - Prfung A: Klte (IEC 60068-2-1:2007) This European Standard was approved by CENELEC on 2007-04-01. CENELEC members are bound to

8、comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for 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 Central

9、 Secretariat or to any CENELEC member. This European Standard exists in 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 Central Secretariat has the same statu

10、s as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Pol

11、and, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of document 104/407/FDIS, future edition 6 of IEC 60068-2-1, prepared by IEC TC 104, Environmental conditions, classification and methods of test, was submitted to the IEC-CENELEC paralle

12、l vote and was approved by CENELEC as EN 60068-2-1 on 2007-04-01. This European Standard supersedes EN 60068-2-1:1993 + A1:1993 + A2:1994. EN 60068-2-1:2007 deals with cold tests applicable both to non heat-dissipating and heat-dissipating specimens. For non heat-dissipating specimens, Tests Ab and

13、Ad do not deviate essentially from earlier issues. Test Ae has been added primarily for testing equipment that requires being operational throughout the test including the conditioning periods. The following dates were fixed: latest date by which the EN has to be implemented at national level by pub

14、lication of an identical national standard or by endorsement (dop) 2008-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-04-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60068-2-1:2007 w

15、as approved by CENELEC as a European Standard without any modification. _ 2 EN 60068-2-1:2007CONTENTS 1 2 3 4 Application of tests for non heat-dissipating specimens versus tests for heat-4.1 4.2 4.3 4.4 4.5 4.6 4.7 5 5.1 5.2 Test Ab: Cold for non heat-dissipating specimens with gradual change of 5.

16、2.1 5.2.2 5.3 Test Ad: Cold for heat-dissipating specimens with gradual change of 5.3.1 5.3.2 5.4 Test Ae: Cold for heat-dissipating specimens with gradual change of 5.4.1 5.4.2 5.4.3 6 6.1 6.2 6.3 6.4 6.5 6.6 6.6.1 6.6.2 6.7 6.8 6.9 3 EN 60068-2-1:2007INTRODUCTION.5 Scope and object6 Normative refe

17、rences .6 Terms and definitions .7 dissipating specimens 7 General .7 Ascertaining high or low air velocity in the test chamber7 Non heat-dissipating specimens 8 Testing of heat-dissipating specimens .8 Temperature monitoring 8 Packaging .8 Diagrammatic representations .8 Test description9 General .

18、9 temperature.9 Object .9 General description .10 temperature that are powered after initial temperature stabilization .10 Object .10 General description .10 temperature that are required to be powered throughout the test.10 Object .10 General description .10 Energizing the specimen .11 Test procedu

19、re .11 Confirmation of performance .11 Working space 11 Thermal radiation 11 Specimen with artificial cooling11 Mounting .12 Severities 12 Temperature12 Duration 12 Preconditioning .12 Initial measurements .12 Conditioning 12 6.10 Intermediate measurements 13 6.11 Final temperature ramp .13 6.12 Rec

20、overy.13 6.13 Final measurements 13 7 8 4 EN 60068-2-1:2007Information to be given in the relevant specification .13 Information to be given in the test report 14 Figure 1 Block diagram tests A: Cold .9 Annex ZA (normative) Normative references to international publications with their corresponding

21、European publications .15INTRODUCTION Relationship of suffixes between tests a: cold and tests b: dry heat The relationship of suffixes between Tests A: Cold, and Tests B: Dry heat, is shown in the following table: Tests A: Cold Tests B: Dry heat Suffix letter Specimen type Temperature change Air ve

22、locity Specimen type Temperature change Air velocity a Withdrawn Withdrawn b Non heat Gradual High preferred Non heat Gradual High preferred c Withdrawn Withdrawn d Heat dissipating Gradual Low preferred Heat Gradual Low preferred e Heat dissipating, powered throughout Gradual Low preferred Heat, po

23、wered throughout Gradual Low preferred 5 EN 60068-2-1:2007ENVIRONMENTAL TESTING Part 2-1: Tests Test A: Cold 1 Scope and object This part of IEC 60068 deals with cold tests applicable to both non heat-dissipating and heat-dissipating specimens. For non heat-dissipating specimens, Tests Ab and Ad do

24、not deviate essentially from earlier issues. Test Ae has been added primarily for testing equipment that requires being operational throughout the test, including the conditioning periods. The object of the cold test is limited to the determination of the ability of components, equipment or other ar

25、ticles to be used, transported or stored at low temperature. Cold tests cover by this standard do not enable the ability of specimens to withstand or operate during the temperature variations to be assessed. In this case, it would be necessary to use IEC 60068-2-14. The cold tests are subdivided as

26、follows: Cold tests for non heat-dissipating specimens with gradual change of temperature, Ab; Cold test for heat-dissipating specimens with gradual change of temperature, Ad, with gradual change of temperature, specimen powered throughout, Ae. The procedures given in this standard are normally inte

27、nded for specimens that achieve temperature stability during the performance of the test procedure. Temperature chamber(s) are constructed and verified in accordance with specifications IEC 60068-3-5 and IEC 60068-3-7. Further guidance for dry heat and cold tests can be found in IEC 60068-3-1 and ge

28、neral guidance in IEC 60068-1. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) appl

29、ies. IEC 60068-1:1988, Environmental testing Part 1: General and guidance IEC 60068-2-14, Basic environmental test procedures Part 2-14: Tests Test N: Change of temperature IEC 60068-3-1, Environmental testing Part 3: Background information Section one: Cold and dry heat tests 6 EN 60068-2-1:2007IEC

30、 60068-3-5, Environmental testing Part 3-5: Supporting documentation and guidance Confirmation of the performance of temperature chambers IEC 60068-3-7, Environmental testing Part 3-7: Supporting documentation and guidance Measurements in temperature chambers for tests A and B (with load) IEC 60068-

31、5-2, Environmental testing Part 5-2: Guide to drafting of test methods Terms and definitions IEC 60721 (all parts), Classification of environmental conditions 3 Terms and definitions For the purposes of this document, the definitions given in IEC 60068-5-2, as well as the following definitions, appl

32、y. 3.1 low air velocity in the working space velocity of conditioning airflow within a working space which is sufficient to maintain conditions but low enough so that the temperature at any point on the test specimen is not reduced by more than 5 K by the influence of the circulation of the air (if

33、possible, not more than 0,5 m/s) 3.2 high air velocity in the working space velocity of conditioning airflow within a working space, which in order to maintain conditions, also reduces the temperature at any point on the test specimen by more than 5 K by the influence of the circulation of the air 4

34、 Application of tests for non heat-dissipating specimens versus tests for heat-dissipating specimens 4.1 General A specimen is considered to be heat-dissipating only if the hottest point on its surface, measured in free air conditions (i.e. with low air velocity circulation), is more than 5 K above

35、the ambient temperature of the surrounding atmosphere after temperature stability has been reached (see 4.8 of IEC 60068-1). When the relevant specification calls for a storage or transportation test, or does not specify an applied load during the test, the Cold Test Ab will apply. 4.2 Ascertaining

36、high or low air velocity in the test chamber Under standard atmospheric conditions for measurements and test (see IEC 60068-1) with an air velocity 0,2 m/s achieved without induced air movement, the specimen shall be switched on or electrically loaded as specified for the low temperature at which th

37、e test is to be carried out. When temperature stability of the specimen has been reached, the temperature of a number of representative points around or on the specimen shall be measured using a suitable monitoring device. The temperature rise that occurs at each point shall then be noted. 7 EN 6006

38、8-2-1:2007The chamber is switched on and, once temperature stability has been achieved, the temperature of the representative points shall again be measured. If the temperatures differ from those measured without air flow by more than 5 K (or a value stated by the relevant specification) this value

39、shall be noted in the test report and the test chamber is considered to have high velocity circulation. The specimen is then switched off and any loading conditions removed. 4.3 Non heat-dissipating specimens In Test Ab with gradual change of temperature, the specimen is introduced into the test cha

40、mber, the latter being at the laboratory temperature. The temperature in the chamber is then reduced gradually so as to cause no detrimental effects on the test specimen due to the temperature change. High air velocity is recommended as this will reduce the time required for temperature stabilizatio

41、n. 4.4 Testing of heat-dissipating specimens Tests Ad and Ae describe procedures for testing heat-dissipating specimens with low air velocity circulation. This is to allow localized hot spots to develop within the specimen similar to those that would appear in installed applications. 4.5 Temperature

42、 monitoring The air temperature in the chamber shall be measured by temperature sensors located at such a distance from the specimen that the effect of the dissipation is negligible. Suitable precautions shall be taken to avoid heat radiation affecting these measurements. For more information see IE

43、C 60068-3-5. 4.6 Packaging For storage and transportation tests, equipment may be tested with its packaging in place. However, as these tests are steady-state tests, the equipment will eventually stabilize at chamber temperature. Packaging shall be removed unless the relevant specification requires

44、it to remain in place, or heating elements are incorporated in the package. 4.7 Diagrammatic representations To facilitate the choice of test method, a diagrammatic representation of the various procedures is given in Figure 1. 8 EN 60068-2-1:2007Tests A: Cold Heat dissipating? NoNoYes Yes Powered d

45、uring conditioning period? Test Ab See Clause 5.2 Test Ad See Clause 5.3 Test Ae See Clause 5.4 IEC 350/07 Figure 1 Block diagram tests A: Cold 5 Test description 5.1 General Tests Ab, Ad, and Ae are similar. Differences are noted in 5.2.2, 5.3.2 and 5.4.2. All other portions of the test are the sam

46、e, starting with Clause 6. The rate of change of temperature within the chamber shall not exceed 1 K per minute, averaged over a period of not more than 5 min. The relevant specification shall define the functioning of the specimen under test. Care shall be taken to see that any cooling devices of t

47、he specimen are in accordance with the requirement in the relevant specification. 5.2 Test Ab: Cold for non heat-dissipating specimens with gradual change of temperature 5.2.1 Object This procedure is intended for non heat-dissipating specimens which are subjected to a lower temperature for a time l

48、ong enough for the specimen to achieve temperature stability. 9 EN 60068-2-1:20075.2.2 General description The specimen is introduced into the chamber which is at the temperature of the laboratory. The temperature is then adjusted to the temperature appropriate to the degree of severity, as specifie

49、d in the relevant specification. After temperature stability of the test specimen has been reached, the specimen is exposed to these conditions for the specified duration. For specimens that are required to be operational (even though they do not meet the requirements of being heat dissipating), power shall then be applied to the specimen and a functional test is performed as necessary. A further period of stabilization may be necessary and the spec