IEC 60068-2-1-2007 Environmental testing - Part 2-1 Tests - Test A Cold《环境试验.第2-1部分 试验.试验A 低温》.pdf

1、 Environmental testing Part 2-1: Tests Test A: Cold Reference number IEC 60068-2-1:2007(E) INTERNATIONAL STANDARD IEC60068-2-1Sixth edition2007-03This English-language version is derived from the original bilingual publication by leaving out all French-language pages. Missing page numbers correspond

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8、vice Centre: Email: custserviec.ch Tel: +41 22 919 02 11 Fax: +41 22 919 03 00 Environmental testing Part 2-1: Tests Test A: Cold For price, see current catalogue IEC 2007 Copyright - all rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electroni

9、c or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec.ch I

10、NTERNATIONAL STANDARD IEC60068-2-1Sixth edition2007-03N Commission Electrotechnique InternationaleInternational Electrotechnical Commission PRICE CODE 60068-2-1 IEC:2007 3 CONTENTS FOREWORD.7 INTRODUCTION.11 1 Scope and object13 2 Normative references .13 3 Terms and definitions .15 4 Application of

11、 tests for non heat-dissipating specimens versus tests for heat-dissipating specimens 15 4.1 General .15 4.2 Ascertaining high or low air velocity in the test chamber15 4.3 Non heat-dissipating specimens 17 4.4 Testing of heat-dissipating specimens .17 4.5 Temperature monitoring 17 4.6 Packaging .17

12、 4.7 Diagrammatic representations .17 5 Test description19 5.1 General .19 5.2 Test Ab: Cold for non heat-dissipating specimens with gradual change of temperature.19 5.2.1 Object .19 5.2.2 General description .21 5.3 Test Ad: Cold for heat-dissipating specimens with gradual change of temperature tha

13、t are powered after initial temperature stabilization .21 5.3.1 Object .21 5.3.2 General description .21 5.4 Test Ae: Cold for heat-dissipating specimens with gradual change of temperature that are required to be powered throughout the test.21 5.4.1 Object .21 5.4.2 General description .21 5.4.3 Ene

14、rgizing the specimen .23 6 Test procedure .23 6.1 Confirmation of performance .23 6.2 Working space 23 6.3 Thermal radiation 23 6.4 Specimen with artificial cooling23 6.5 Mounting .25 6.6 Severities 25 6.6.1 Temperature25 6.6.2 Duration 25 6.7 Preconditioning .25 6.8 Initial measurements .25 6.9 Con

15、ditioning 25 6.10 Intermediate measurements 27 6.11 Final temperature ramp .27 6.12 Recovery.27 6.13 Final measurements 27 60068-2-1 IEC:2007 5 7 Information to be given in the relevant specification .27 8 Information to be given in the test report 29 Figure 1 Block diagram tests A: Cold .19 60068-2

16、1 IEC:2007 7 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ENVIRONMENTAL TESTING Part 2-1: Tests Test A: Cold FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees).

17、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 Spec

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22、ional Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides n

23、o marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, s

24、ervants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the public

25、ation, use of, or reliance upon, this IEC Publication or any other IEC Publications. 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 possibil

26、ity 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 60068-2-1 has been prepared by IEC technical committee 104: Environmental conditions, classification

27、and methods of test. This sixth edition cancels and replaces the fifth edition issued in 1990. It includes the revised text of the fifth edition, amendment 1 issued in 1993 and amendment 2 issued in 1994. This sixth edition deals with cold tests applicable both to non heat-dissipating and heat-dissi

28、pating specimens. For non heat-dissipating specimens, Tests Ab and Ad do not deviate essentially from earlier issues. Test Ae has been added primary for testing equipment that requires being operational throughout the test including the conditioning periods. 60068-2-1 IEC:2007 9 The text of this sta

29、ndard is based on the following documents: FDIS Report on voting 104/407/FDIS 104/410/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, P

30、art 2. 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 maintenance result date indicated on the IEC web site under “http:/w

31、ebstore.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. 60068-2-1 IEC:2007 11 INTRODUCTION Relationship of suffixes between tests a: cold and tests b: dry heat The relationship of suffix

32、es 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 velocity Specimen type Temperature change Air velocity a Withdrawn Withdrawn b Non heat Gradual High preferred Non heat Gradual High pr

33、eferred c Withdrawn Withdrawn d Heat dissipating Gradual Low preferred Heat Gradual Low preferred e Heat dissipating, powered throughout Gradual Low preferred Heat, powered throughout Gradual Low preferred 60068-2-1 IEC:2007 13 ENVIRONMENTAL TESTING Part 2-1: Tests Test A: Cold 1 Scope and object Th

34、is 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 not deviate essentially from earlier issues. Test Ae has been added primarily for testing equipment that requires being operationa

35、l 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 articles to be used, transported or stored at low temperature. Cold tests cover by this standard do not enable the ability of specim

36、ens 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 follows: Cold tests for non heat-dissipating specimens with gradual change of temperature, Ab; Cold test for heat-dissipating spec

37、imens with gradual change of temperature, Ad, with gradual change of temperature, specimen powered throughout, Ae. The procedures given in this standard are normally intended for specimens that achieve temperature stability during the performance of the test procedure. Temperature chamber(s) are con

38、structed 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 general guidance in IEC 60068-1. 2 Normative references The following referenced documents are indispensable for the application of

39、this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60068-1:1988, Environmental testing Part 1: General and guidance IEC 60068-2-14, Basic environmental test procedures Part

40、 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 60068-2-1 IEC:2007 15 IEC 60068-3-5, Environmental testing Part 3-5: Supporting documentation and guidance Confirmation of the performance of temperatur

41、e 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 60068-5-2, Environmental testing Part 5-2: Guide to drafting of test methods Terms and definitions IEC 60721 (all parts), Classificat

42、ion 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, apply. 3.1 low air velocity in the working space velocity of conditioning airflow within a working space which is sufficient to mai

43、ntain 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 possible, not more than 0,5 m/s) 3.2 high air velocity in the working space velocity of conditioning airflow within a working s

44、pace, 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 Application of tests for non heat-dissipating specimens versus tests for heat-dissipating specimens 4.1 General A specimen is

45、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 the ambient temperature of the surrounding atmosphere after temperature stability has been reached (see 4.8 of IEC 60068-1). Wh

46、en 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 high or low air velocity in the test chamber Under standard atmospheric conditions for measurements and test (see IEC 60068-1)

47、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 the test is to be carried out. When temperature stability of the specimen has been reached, the temperature of a number of repres

48、entative 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. 60068-2-1 IEC:2007 17 The chamber is switched on and, once temperature stability has been achieved, the temperature of the representativ

49、e 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 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 temperatu