环境试验.第2-27部分:试验.试验Ea和指南:冲击

[中文适用范围]： IEC 60068 的这一部分提供了一种标准程序，用于确定样品承受规定强度的非重复或重复冲击的能力。该测试的目的是揭示机械弱点和/或规定性能的下降，或冲击造成的累积损坏或下降。结合相关规范，这在某些情况下可用于确定样品的结构完整性或作为质量控制手段（见条款 A.2）。该测试主要用于未包装的样品和运输箱中的物品，后者可被视为样品的一部分。如果要测试未包装的物品，则将其称为测试样品。但是，如果物品已包装，则物品本身称为产品，物品及其包装一起称为测试样品。当与 IEC 60068-2-47 结合使用时，本标准可用于测试包装产品。这种可能性首次被纳入 IEC 60068-2-47 的 2005 版中。本标准以规定的脉冲形状编写。附录 A 给出了这些脉冲的选择和应用指南，附录 B 讨论了不同脉冲形状的特性。只要可能，试验严酷度和施加到样品的冲击脉冲形状应该能够重现样品将要承受的实际运输或操作环境的影响，或者，如果试验目的是评估结构完整性，则应满足设计要求（见条款 A.2 和 A.4）。为了进行这种试验，在试验过程中，样品始终安装在冲击试验机的夹具或工作台上。注：本标准通篇使用术语“冲击试验机”，但不排除其他施加脉冲形状的方法。技术委员会的职责之一是，在适用的情况下，在编制其出版物时利用基本安全出版物。 [外文原描述]： IEC 60068-2-27:2008 provides a standard procedure for determining the ability of a specimen to withstand specified severities of non-repetitive or repetitive shocks. The purpose of this test is to reveal mechanical weakness and/or degradation in specified performances, or accumulated damage or degradation caused by shocks. In conjunction with the relevant specification, this may be used in some cases to determine the structural integrity of specimens or as a means of quality control. This test is primarily intended for unpackaged specimens and for items in their transport case when the latter may be considered to be part of the specimen. If an item is to be tested unpackaged, it is referred to as a test specimen. However, if the item is packaged, then the item itself is referred to as a product and the item and its packaging together are referred to as a test specimen. When used in conjunction with IEC 60068-2-47, this standard may be used for testing packaged products. This possibility was included in the 2005 version of IEC 60068-2-47 for the first time. This standard is written in terms of prescribed pulse shapes. Guidance for the selection and application of these pulses is given in Annex A and the characteristics of the different pulse shapes are discussed in Annex B. Wherever possible, the test severity and the shape of the shock pulse applied to the specimen should be such as to reproduce the effects of the actual transport or operational environment to which the specimen will be subjected, or to satisfy the design requirements if the object of the test is to assess structural integrity (see Clauses A.2 and A.4). For the purposes of this test, the specimen is always mounted to the fixture or the table of the shock testing machine during testing. The major changes with regard to the previous edition concern: - the merging of IEC 60068-2-29 into this edition of IEC 60068-2-27; Part 2-29 will be withdrawn as soon as this edition is published; - the introduction of soft packaged specimens as defined in the IEC ad hoc working group document agreed in Stockholm:2000.