1、BRITISH STANDARD BS EN 60068-2-7:1993 IEC 68-2-7: 1983 (including Amendment No.1: 1986) Environmental testing Part 2: Tests Test Ga and guidance: Acceleration, steady state The European Standard EN 60068-2-7:1993 has the status of a British Standard This Part should be read in conjunction with BS 20
2、11-1.1:1989 General and guidance UDC 621.3:620.193:620.199BSEN60068-2-7:1993 This British Standard, having been prepared under the directionof the General Electrotechnical Standards PolicyCommittee, was publishedunder the authority ofthe Standards Board and comesinto effect on 15 June 1993 BSI 03-19
3、99 The following BSI references relate to the work on this standard: Committee reference GEL/15 Draft for comment 82/32381 DC ISBN 0 580 22179 2 Cooperating organizations The European Committee for Electrotechnical Standardization (CENELEC), under whose supervision this European Standard was prepare
4、d, comprises the national committees of the following countries: Austria Italy Belgium Luxembourg Denmark Netherlands Finland Norway France Portugal Germany Spain Greece Sweden Iceland Switzerland Ireland United Kingdom Amendments issued since publication Amd. No. Date CommentsBSEN60068-2-7:1993 BSI
5、 03-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 Text of EN 60068-2-7 3 National annex NA (informative) Committees responsible Inside back cover National annex NB (informative) Cross-references Inside back coverBSEN60068-2-7:1993 ii BSI 03-1999 Na
6、tional foreword This British Standard has been prepared under the direction of the General Electrotechnical Standards Policy Committee and is the English language version of EN60068-2-7:1993 Basic environmental testing procedures Part2:Tests Test Ga and guidance: Acceleration, steady state. It is id
7、entical with IEC68-2-7:1983 Basic Environmental testing procedures, Part2: Tests Test Ga and guidance. Acceleration, steady state including Amendment 1:1986, published by the International Electrotechnical Commission (IEC). It supersedes BS2011-2.1Ga:1984 which is withdrawn. This edition constitutes
8、 a reprint of the 1984 edition of BS2011-2.1Ga including Amendment 1:1987 and was published to bring the numbering system of the British Standard into line with the European Standard EN60068-2-7. This British Standard is the implementation of EN60068-2-7:1993 published by CENELEC. The title of BSEN6
9、0068 has been changed to Environmental testing to correspond with the change in title of IEC Publication 68. This change reflects the fact that IEC Publication 68 and BSEN60068 are concerned with the whole subject of testing and avoids any possible confusion over whether it is the procedures or the
10、testing that are basic. Amendments are not being issued to the other Parts of BSEN60068, but their titles are to be changed when these Parts are reviewed. WARNING. This British Standard calls for the use of procedures that may be injurious to health if adequate precautions are not taken. It refers o
11、nly to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Complianc
12、e with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages2 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date
13、) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60068-2-7 March 1993 UDC 621.3:620.193:620.199 Supersedes HD 323.2.7 S2:1987 Descriptors: Electricity, components, equipment, climat
14、ic test, mechanical test, steady acceleration, procedures, components specifications writing, equipment specifications writing English version Basic environmental testing procedures Part 2: Tests Test Ga and guidance: Acceleration, steady state (IEC 68-2-7:1983 + A1:1986) Essais fondamentaux climati
15、ques et de robustesse mcanique Deuxime partie: Essais Essia Ga et guide: Acclration constante (CEI 68-2-7:1983 + A1:1986) Grundlegende Umweltprfverfahren Teil 2: Prfungen Prfung Ga und Leitfaden: Gleichfrmiges Beschleunigen (IEC 68-2-7):1983 + A1:1986) This European Standard was approved by CENELEC
16、on 1993-03-09. CENELEC members are bound to 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 m
17、ay be obtained on application to the Central 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 t
18、o the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and Unit
19、ed Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1993 Copyright reserved to CENELEC members Ref. No. EN 60068-2-7:1993
20、EEN60068-2-7:1993 2 BSI 03-1999 Foreword At the request of CENELEC Reporting Secretariat SR50A, HD323.2.7 S2:1987 (IEC68-2-7:1983 + A1:1986) was submitted to the CENELEC voting procedure for conversion into a European Standard. The text of the International Standard and its amendment 1 was approved
21、by CENELEC as EN60068-2-7 on 9 March 1993. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. Contents Page Foreword 2 1 Object 3 2 General 3 3 Conditions for testing 3 4 Severity 3 5 Initial measurements 4 6
22、Conditioning: procedure for testing with a centrifuge 4 7 Final measurements 4 8 Information to be given in the relevant specification 4 Appendix A Guidance 5 Appendix B Additional guidance 6 Annex Za (normative) Other international publications quoted in this standard with thereferences of the rele
23、vant European publications 7 Table I Examples of test severities typically employed for various applications 6 latest date of publication of an identical national standard (dop) 1994-03-01 latest date of withdrawal of conflicting national standards (dow)EN60068-2-7:1993 BSI 03-1999 3 1 Object To pro
24、ve the structural suitability and the satisfactory performance of components, equipment and other electrotechnical products, hereinafter referred to as “specimens”, when subjected to forces produced by steady acceleration environments (other than gravity) such as occur in moving vehicles, especially
25、 flying vehicles, rotating parts and projectiles, and to provide a test of structural integrity for certain components. 2 General Equipment, components and other electrotechnical products intended to be installed in moving bodies will be subjected to forces caused by steady accelerations. Naturally,
26、 such an environment is most pronounced in flying vehicles and rotating machinery, although in certain conditions accelerations in land vehicles may be of significant magnitude. In general, the accelerations encountered in service have different values along each of the major axes of the moving body
27、, and, in addition, usually have different values in the opposite senses of each axis. If the attitude of the specimen is not fixed with regard to the moving body, then the relevant specification should prescribe a level, which may be applied along each of the major axes and senses of the specimen,
28、having taken into account the maximum accelerations in different axes of the moving body. This standard is to be used in conjunction with IECPublication 68-1: Basic Environmental Testing Procedures, Part 1: General and Guidance. 3 Conditions for testing 3.1 Characteristics of the test apparatus 3.1.
29、1 General Acceleration conditions are applied by means of a centrifuge where the acceleration is directed towards the centre of the rotating system. In certain special cases, however, the specimen may be sensitive to gyroscopic couples, and it may only be possible to perform the test by using a mach
30、ine capable of applying linear acceleration, in which case the relevant specification shall state this requirement. 3.1.2 Tangential acceleration When increasing the rotational speed of a centrifuge from zero to the value necessary to achieve the specified acceleration, or when decreasing back to ze
31、ro, the machine shall be so controlled that the specimen is not subjected to a value of tangential acceleration greater than 10% of the specified acceleration. 3.1.3 Acceleration gradient The dimensions of a centrifuge relative to the specimen shall be such that no part of the specimen, other than f
32、lying leads, shall be subjected to a value of acceleration outside the tolerances given in Sub-clause3.1.4. 3.1.4 Acceleration tolerance If the linear dimensions of the specimen are less than 10cm, the acceleration on all parts of the specimen (excluding flying leads) shall not depart from the speci
33、fied steady-state acceleration by more than 10%. In other cases, the tolerance on the specified steady-state acceleration is 10%+30%. 3.2 Mounting The specimen shall be mounted on the test apparatus in accordance with the requirements in IEC Publication 68-2-47: Basic Environmental Testing Procedure
34、s. Part 2: Tests Mounting of Components, Equipment and Other Articles for Dynamic Tests Including Shock (Ea), Bump (Eb), Vibration (Fc and Fd) and Steady-state Acceleration (Ga) and Guidance. NOTEFor reasons of safety, care should be taken to prevent the specimens under test from being thrown off if
35、 the mounting attachments are broken but any safety devices used should not introduce additional constraint during the test. 4 Severity The relevant specification shall prescribe an acceleration value for the test, chosen, where possible, from the standard values listed below. It shall also prescrib
36、e the angle, with respect to the axes of the specimen, at which this acceleration is to be applied, where it is necessary (Clauses A1, A2 andB2). NOTEThe value prescribed for the acceleration should take into account the purpose of the test, whether it is to be made for checking the structural integ
37、rity of the specimen or to assess the ability of the specimen to withstand the forces occurring in moving vehicles or rotating machinery.EN60068-2-7:1993 4 BSI 03-1999 The standard levels of test are: NOTEThis note is included for the benefit of those who might still wish to give values of accelerat
38、ion in terms of “g n ” or the deprecated “g”. g nis defined as the standard acceleration due to the earths gravity which itself varies with altitude and geographical latitude. For the purposes of this standard, the value of g nis rounded up to the nearest unity, that is 10m/s 2 . 5 Initial measureme
39、nts The specimen shall be submitted to the visual, dimensional and functional checks prescribed by the relevant specification. 6 Conditioning: procedure for testing with a centrifuge 6.1 Unless otherwise stated in the relevant specification, the acceleration conditioning shall be imposed in both sen
40、ses of three mutually perpendicular axes in turn, which shall be the three major axes. 6.2 The centrifuge shall be rotated at the speed necessary to produce the specified level. 6.3 The necessary speed of rotation shall be maintained for not less than 10s or for a period stated in the relevant speci
41、fication. 6.4 The relevant specification shall prescribe which of the following conditions of functioning or survival has to be satisfied and the corresponding acceleration level(s) (Clause A2): 1) Specimen to function within the performance limits given in the relevant specification. 2) Specimen to
42、 function, but not necessarily within the performance limits, but should suffer no permanent derangement. 3) Specimen not to suffer any permanent derangement, but need not function. 4) Specimen not to break loose, although it may be permanently damaged or deranged. 6.5 The relevant specification sha
43、ll prescribe the order in which the checks in Sub-clause6.4 are to be applied (Clause A2). 7 Final measurements The specimen shall be submitted to the visual, dimensional and functional checks as prescribed by the relevant specification. 8 Information to be given in the relevant specification When t
44、his test is included in a relevant specification, the following details shall be given as far as they are applicable: Acceleration m/s 2 30 50 100 200 500 1000 2000 5000 10000 20000 50000 100000 200000 300000 500000 a) Type of test apparatus Sub-clause3.1 b) and c) Methods of mounting thespecimen Su
45、b-clause3.2 d) Acceleration level(s) (ClausesA2 and B2) Clause4 e) Axes and direction of acceleration (ClauseA1) Clauses4, 6 f) Initial measurements Clause5 g) Duration of conditioning Sub-clause6.3 h) Conditions of functioning orsurvival (ClauseB1) Sub-clause6.4 j) Order of checks Sub-clause6.5 k)
46、Final measurements Clause7EN60068-2-7:1993 BSI 03-1999 5 Appendix A Guidance A1 Specimen orientation for test In many applications, especially aircraft, the forces on the moving body giving rise to acceleration are invariably complex but can be considered, at any instant, to be a single force which
47、can be described in direction by its angular position relative to the three main axes of the moving body. For design purposes, the maximum acceleration levels for a particular manuvre of the moving body are resolved and specified with respect to each major axis of the moving body. If a specimen has
48、a known fixed attitude with respect to a given moving body, and in cases where it is necessary to simulate the three components of acceleration simultaneously, these can be combined and the specimen subjected to a single acceleration equal in magnitude and direction to the resultant of the three com
49、ponent levels. Such action would necessitate rather complicated jigs, in order to orientate a specimen relative to the test machine in such a manner that the acceleration is directed along the line of the resultant. Unless it is important to preserve the angular relationship between the resultant acceleration and the specimen, it is simpler and usually adequate to apply the resultant acceleration along the major axis of the specimen having the highest of the three specified component levels; in the remaining axes the appropriate component a
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