1、EUROPEAN STANDARD NORME EUROPEENNE EUROPISCHE NORM m 3404583 0060443 OT3 m EN 60068-2-7 March 1993 UC 621.3 : 620.193 : 620.199 Supersedes HD 323.2.7 S2 : 1987 Descriptors: Electricity, components, equipment, climatic test, mechanical test, steady acceleration, procedures, components specifications
2、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 + Al : 1986) Essais fondamentaux climatiques et de robustesse mcanique Ri1 2: Prfungen Deuxime partie: Essais Essia Ga et
3、 guide: Acclration constante Grundlegende Umweltprfverfahren Prfung Ga und Leitfaden: Gleichfrmiges Beschleunigen (CE1 68-2-7 : 1983 + Al : 1986) (IEC 68-2-7) : 1983 + Al : 1986) This European Standard was approved by CENELEC on 1993-03-09. CENELEC members are bound to comply with the CENICENELEC In
4、ternal 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 Secretariat or to any CENELEC
5、 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 status as the official versions. CE
6、NELEC 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 United Kingdom. CENELEC European Committee for Electrotechnical Standardizatio
7、n Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1993 Copyright reserved to CENELEC members Ref. No. EN 60068-2-7 : 1993 E m 3404583 0060444 T3T = Page 2 EN 60068-2-7 1993 Foreword At the req
8、uest of CENELEC Reporting Secretariat 1983 + Al : 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 by CENELEC as EN 60068-2-7 on 9 March 1993. The foliowing dates were fixed: SR 50A, H
9、I) 323.2.7 S2 : 1987 (IEC 68-2-7 : - latest date of publication of an identical national standard (dop) 1994-03-01 - latest date of withdrawal of conflicting national standards (dow) - Annexes designated normative are part of the body of the standard. in this standard, annex ZA is normative. Content
10、s Object General Conditions for testing Severity Initial measurements Conditioning: procedure for testing with a centrifuge Final measurements Information to be given in the relevant specification Appendices A Guidance B Additional guidance I in the remaining axes the appropriate component accelerat
11、ion levels would be applied. When the attitude of the specimen with respect to the vehicle is not known, the maximum resultant level for the particular moving body should be applied in each direction in turn along each of the three major axes of the specimen. A2. Acceleration levels Some of the acce
12、leration values listed in Clause 4 represent actual environments and others, especially at the higher levels, represent artificial environments used for the structural integrity testing of some electronic components. Bearing in mind the high acceleration figures which may occur in rotating machinery
13、, the actual levels for some purposes may overlap with the artificial levels for other purposes. Design approval for aircraft equipment requires that equipment be tested in turn for operation and survival at different levels of acceleration. The operational and survival requirements are related by a
14、 defined factor, which is stated in the design requirements for aircraft equipment. There are normally four conditions to be satisfied : 1) Proof or operational level - normally, the specimen would be required to function at this level, without degradation in performance outside specification limits
15、. 2) An additional higher level may be prescribed which allows the specimen to function 3) Structural or ultimate levels - a higher level of acceleration to check resistance to although not necessarily within the stated limits. structural deformation. m 3404583 00bO450 233 m Page 8 EN 60068-2-7 : 19
16、93 4) In addition, an acceleration conditioning may be required as a means of checking the ability of a specimen to remain firmly attached to its mounting and not to break loose during emergency conditions in a manner liable to create a hazard to personnel, either directly or by interference with em
17、ergency exits, etc. The relevant specification should state which of these conditions is to be met, the acceleration levels to be applied, and the conditions of operation to be satisfied (see Sub-clauses 6.4 and 6.5). In some applications, the writer of the relevant specification may not always pres
18、cribe separate levels corresponding to Items 1) to 4) above and may instead state one level only, which is related by an agreed safety factor to the maximum measured or calculated acceleration for the moving body concerned. When such a test is invoked, the relevant specification states the type of p
19、erformance required (see Sub-clauses 6.4 and 6.5). When choosing the severity of accelerations to be applied, the relevant specification should take into account the fact that, in a given direction, the maximum acceleration may differ considerably from place to place in the moving body. Certain comp
20、onents, notably from the semiconductor industry, are checked for structural integrity (sound mechanical assembly) by the application of a very high acceleration. Although such a level has no correlation with actual service conditions, the tests are used as a simple means of applying a high stress to
21、 reveal possible constructional weaknesses. When testing components or equipment containing rotating parts, for example gyroscopes, some difficulties may arise when using a centrifuge, due to the coupling between the rotation of the part and the rotation of the centrifuge. In such cases, the relevan
22、t specification should advise a suitable test method, and indicate the appropriate functional cqnditions and the acceptable changes in functional tolerances for the specimen during conditioning. = 3404583 OObOLi51 1T Page 9 EN 60068-2-7 : 1993 APPENDIX B ADDITIONAL GUIDANCE BI. Object of the test Th
23、e purpose of the acceleration, steady-state test is to produce in components and equipment steady acceleration effects similar to those to which they would be subjected when mounted in rotating parts, projectiles, and moving vehicles, particularly space vehicles. The test may also be used as a means
24、 of establishing the satisfactory design and manufacture of a component, in so far as its structural integrity is concerned. Whether specimens shall function during the test or merely survive conditions of steady acceleration, should be clearly stated in the relevant specification. In either case, t
25、he relevant specification should always prescribe the acceptable tolerance in performance and/or permissible derangement, as required by Sub-clause 6.4, which allows the specimen to be considered as satisfactory or otherwise. B2. Selection of test severities (See Clauses 4 and 6 and Clause 8, Items
26、d) and g) See the test levels in Clause A2 of Appendix A. The specification writer intending to prescribe this test should refer to Clause 8 to ensure that all such information is included in the relevant specification. Wherever possible, the test severity applied to the specimen should be related t
27、o the expected conditions to which the specimen will be subjected during either transportation or operation. If this information is available, an appropriate severity should be selected from the values given in Clause 4. When the severity of the environment is not available, the most suitable severi
28、ty should be selected by the specification writer from Table I which lists examples of test severities appropriate to specimens intended for various applications. Note. - The attention of the reader is drawn to IEC Publication 721: Classification of Environmental Conditions, recalling that the vario
29、us parts of this publication are concerned with values of steady-state acceleration encountered in practice whereas the intention of this present publication is to standardize values for testing that are likely to produce the same effects as the real life environment. W 3404583 0060452 006 W 30 d a
30、6 100 Page 10 EN 60068-2-7 : 1993 Proof level for specimens to be mounted in aircraft TABLE I Examples of test severities typically employed for various applications 1006a1000 a2 so00 This table is not mandatory, but lists severities which are typical; it should be borne in mind that there will be i
31、nstances where the actual severities experienced differ from those shown in the table. General testing for aerospace applications Structural integrity tests for semiconductor devices, integrated circuits, etc. Acceleration, u m/s2 Application 50 Qu g2 Structural or ultimate levei for specimens to be
32、 mounted in aircraft and for crash safety of mountings B3. Tolerance requirements (See Sub-clauses 3.1.2 and 3.1.4) This test method is capable of a high degree of reproducibility when the linear dimensions of the specimen are small, for example less than 1Ocm. For larger specimens, the reproducibil
33、ity is of a lower order, dependent on the relative dimensions of the specimen and the centrifuge. = 3404583 O060453 T42 Page 11 EN 60068-2-7 : 1993 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications When the interna
34、tional publication has been modified by CENELEC common modifications, indicated by (mod), the relevant ENHD applies. IEC publication Date Titie ENIHD Date 68- 1 1988 Basic environmental testing procedures HD 323.1 S2 1988 68-2-47 1982 Part 2: %sts - Mounting of components, EN 60068-2-47 1993 part 1: General and guidance equipment and other articles for dynamic tests including shock (Ea), bump (Eb), vibration (Fc and Fd) and steady-state acceleration (Ga) and guidance series Classification for environmentai conditions HD 478 72 1 series
