Environmental testing—Part 2: Test methods—Test Ec: Rough handling shocks, primarily for equipment-type specimens
1 Scope
This part of GB/T 2423 deals with a test procedure for simulating the effects of rough handling shocks, primarily in equipment-type specimens, the effects of knocks, jolts and falls which may be received during repair work or rough handling in operational use.
Where the effects of loose cargo transportation are to be assessed, test Ee: Bounce shall be used. Also, where this effect is to be assessed refer to test Ea: Shock.
Generally, this test is only applicable to small to medium size equipment likely to receive such rough handling, and only be applied to those faces and corners where there is a risk of such treatment being encountered.
In general, equipment which is frequently handled and serviced (for example field equipment and unit spares) can be considered at such risk. Whereas equipment forming an integral part of a permanent installation would not normally be considered at such risk and need not be tested.
Testing may not be applicable to fragile unprotected equipment of irregular shape (for example aircraft nose radar) which, when removed from the installation would be contained in a handling frame or jig. It may however be applicable to these items of equipment when they are in their transit case or in their handling frame or jig.
For equipment which stands only on one face (for example the normal base) the test is generally only applied to that face.
Shock tests are performed on the specimen when fixed to the test machine. Drop and topple, free fall, repeated free fall and bounce tests are performed with the specimen free.
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 references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2423.39-2008 Environmental testing for electric and electronic products—Part 2: Test methods—Test Ee: Bounce (IEC 60068-2-55: 1987, IDT)
IEC 60068-2-27 Environmental testing—Part 2-27: Tests—Test Ea and guidance: Shock
IEC Guide 104 The preparation of safety publications and the use of basic safety publications and group safety publications
ISO 48:2007 Rubber, vulcanized or thermoplastic—Determination of hardness (hardness between 10 IRHD and 100 IRHD)
ISO 4180-2: 1980 Complete, filled transport packages—General rules for the compilation of performance test schedules—Part 2: Quantitative data
3 General description of test
Rough handling shocks can be simulated by one or more of the following tests:
a) Drop and topple: A simple test intended to assess the effects of knocks or jolts likely to be received primarily by equipment-type specimens during repair work or rough handling on a table or bench.
b) Free fall C Procedure 1: A simple test to assess the effects of falls likely to be experienced due to rough handling. It is also suitable to demonstrate a degree of robustness.
c) Free fall C Procedure 2: A test that simulates repetitive shocks likely to be received by certain component-type specimens, for example connectors in service.
The topple test need not be applied to specimens which have dimensions which make them stable whilst being handled. Reference to points 1) and 2) below should be made for information on the “C C g ratio” and “height ratio” to establish if the test is necessary.
The falling or topple actions produced by the test procedures given in 5.1.3.1, 5.1.3.2 and 5.1.3.3 are illustrated by Figures 1, 2 and 3. The drop and topple test includes three distinct procedures:
a) Dropping on to a face (5.1.3.1);
b) Dropping on to an edge or a corner (5.1.3.2);
c) Toppling (or pushover) (5.1.3.3).
The purpose of each of these procedures is basically the same, but they represent different kinds of handling.
The test is not intended to be a precise test and a tolerance of ±10 % is allowed on the heights and angles prescribed in 5.1.2.
For a more precise shock test, IEC 60068-2-27 shall be used.
The topple test need not be applied to specimens which have dimensions which make them stable while being handled. When considering the applicability of the topple test, two dimensional ratios are important:
1) The ratio of the height of the centre of gravity from the base, to the smaller dimension of the base, hereinafter referred to as the C C g ratio;
2) The ratio of the height of the specimen to the smaller dimension of the base, hereinafter referred to as the height ratio.
If the C C g ratio is small, for example less than 0.25, the specimen is unlikely to fall over due to sudden sideways displacements. If the height ratio is small, for example less than 0.5, the specimen is unlikely to topple over due to a sudden sideways force or blow at the top. In such cases the writer of the relevant specification shall consider whether the topple test is applicable.
GB/T 2423.7-2018 The following standards are cited：
GB/T 2423.7-2018 Cited by the following standards：
