1、 IEC 60068-2-14Edition 6.0 2009-01INTERNATIONAL STANDARD NORME INTERNATIONALEEnvironmental testing Part 2-14: Tests Test N: Change of temperature Essais denvironnement Partie 2-14: Essais Essai N: Variation de temprature IEC60068-2-14:2009 BASIC SAFETY PUBLICATION PUBLICATION FONDAMENTALE DE SCURITT
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16、ts ou contactez-nous: Email: csciec.ch Tl.: +41 22 919 02 11 Fax: +41 22 919 03 00 IEC 60068-2-14Edition 6.0 2009-01INTERNATIONAL STANDARD NORME INTERNATIONALEEnvironmental testing Part 2-14: Tests Test N: Change of temperature Essais denvironnement Partie 2-14: Essais Essai N: Variation de tempratu
17、re INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE RICS 19.040 PRICE CODECODE PRIXISBN 2-8318-1022-7BASIC SAFETY PUBLICATION PUBLICATION FONDAMENTALE DE SCURIT Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Ele
18、ctrotechnique Internationale 2 60068-2-14 IEC:2009 CONTENTS FOREWORD.4 INTRODUCTION.6 1 Scope.7 2 Normative references .7 3 Field conditions of changing temperature .7 4 General 8 4.1 Design of change of temperature tests 8 4.2 Test parameters 8 4.3 Purpose and choice of the tests 8 4.4 Choice of th
19、e duration of the exposure 8 4.5 Choice of the duration of the transfer time.9 4.6 Applicability limits of change of temperature tests .9 5 Guidance for the selection of the kind of test 10 6 Initial and final measurements 10 6.1 Initial measurements .10 6.2 Final measurements 10 7 Test Na: Rapid ch
20、ange of temperature with prescribed time of transfer 10 7.1 General description of the test.10 7.2 Testing procedure .10 7.2.1 Testing chamber10 7.2.2 Mounting or supporting of the test specimen11 7.2.3 Severities 11 7.2.4 Conditioning 11 7.2.5 Test cycle11 7.3 Recovery.12 7.4 Information to be give
21、n in the relevant specification 12 8 Test Nb: Change of temperature with specified rate of change .13 8.1 General description of the test.13 8.2 Testing procedure .13 8.2.1 Testing chamber13 8.2.2 Mounting or supporting of the test specimen13 8.2.3 Severities 13 8.2.4 Conditioning 14 8.2.5 Test cycl
22、e14 8.3 Recovery.15 8.4 Information to be given in the relevant specification 15 9 Test Nc: Rapid change of temperature, two-fluid-bath method 16 9.1 General description of the test.16 9.2 Testing procedure .16 9.2.1 Testing equipment .16 9.2.2 Severities 16 9.2.3 Conditioning 16 9.3 Test cycle16 9.
23、4 Recovery.17 9.5 Information to be given in the relevant specification 17 60068-2-14 IEC:2009 3 10 Information to be given in the test report 18 Figure 1 Determination of test duration time (t1).9 Figure 2 Na test cycle 12 Figure 3 Nb test cycle 15 Figure 4 Nc test cycle 17 4 60068-2-14 IEC:2009 IN
24、TERNATIONAL ELECTROTECHNICAL COMMISSION _ ENVIRONMENTAL TESTING Part 2-14: Tests Test N: Change of temperature FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees)
25、. 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 Sp
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31、 no 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,
32、 servants 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 publ
33、ication, 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 possib
34、ility 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 60068-2-14 has been prepared by IEC technical committee 104: Environmental conditions, classificati
35、on and methods of test. This sixth edition cancels and replaces the fifth edition, published in 1984, and its amendment 1 (1986) and constitutes a technical revision. The major changes with regard to the previous edition concern: merging of the previous version of IEC 60068-2-14 with IEC 60068-2-33:
36、 Guidance on change of temperature tests; updating of the figures, changes to some of the wording and editorial corrections made for clarification. 60068-2-14 IEC:2009 5 The text of this standard is based on the following documents: FDIS Report on voting 104/481/FDIS 104/486/RVD Full information on
37、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, Part 2. It has the status of a basic safety publication in accordance with IEC Guide 104. A list of all the par
38、ts 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:/webstore.iec.ch“ in the data
39、related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. 6 60068-2-14 IEC:2009 INTRODUCTION A change of temperature test is intended to determine the effect on the specimen of a change of temperature or a succession
40、 of changes of temperature. It is not intended to show effects which are due only to high or low temperatures. For these effects, the dry heat test or the cold test should be used. The effect of such tests is determined by values of high and low conditioning temperature between which the change is t
41、o be effected, the conditioning times for which the test specimen is kept at these temperatures, the rate of change between these temperatures, the number of cycles of conditioning, the amount of heat transfer into or from the specimen. Guidance on the choice of suitable test parameters for inclusio
42、n in the detail specification is given throughout this standard. 60068-2-14 IEC:2009 7 ENVIRONMENTAL TESTING Part 2-14: Tests Test N: Change of temperature 1 Scope This part of IEC 60068 provides a test to determine the ability of components, equipment or other articles to withstand rapid changes of
43、 ambient temperature. The exposure times adequate to accomplish this will depend upon the nature of the specimen. 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 refere
44、nces, the latest edition of the referenced document (including any amendments) applies. IEC 60068 (all parts), Environmental testing IEC 60068-2-1, Environmental testing Part 2-1: Tests Test A: Cold IEC 60068-2-2, Environmental testing Part 2-2: Tests Test B: Dry heat IEC 60068-2-17, Environmental t
45、esting Part 2-17: Tests Test Q: Sealing IEC Guide 104, The preparation of safety publications and the use of basic safety publications and group safety publications 3 Field conditions of changing temperature It is common in electronic equipment and components that changes of temperature occur. Parts
46、 inside equipment undergo slower changes of temperature than those on an external surface when the equipment is not switched on. Rapid changes of temperature may be expected when equipment is transported from warm indoor environments into cold open air conditions or vice versa, when equipment is sud
47、denly cooled by rainfall or immersion in cold water, in externally mounted airborne equipment, under certain conditions of transportation and storage. Components will undergo stresses due to changing temperature when high temperature gradients build up in an equipment after being switched on, e.g. i
48、n the neighbourhood of high wattage resistors, radiation can cause rise of surface temperature in neighbouring components while other portions are still cool. Artificially cooled components may be subjected to rapid temperature changes when the cooling system is switched on. Rapid changes of tempera
49、ture in components may also be induced during manufacturing processes of equipment. Both the number and amplitude of temperature changes and the time interval between them are important. 8 60068-2-14 IEC:2009 4 General 4.1 Design of change of temperature tests Tests Na, Nb and Nc comprise alternate periods at a high and at a low temperature with well-defined transfers
