Environmental testing for electric and electronic products - Part 2: Test methods - Mounting of specimens for vibration impact and similar dynamic tests
1 Scope
This part of GB/T 2423 provides methods for mounting products, whether packaged or unpackaged, as well as mounting requirements for equipment and other articles, for the series of dynamic tests in GB/T 2423, that is impact (Test E), vibration (Test F) and acceleration, steady-state (Test G). When they are fastened to the test apparatus and subjected to these tests, whether packaged or unpackaged, they are referred to as specimens.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of GB/T 2423. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part. However parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 2421-1999 Environmental testing for electric and electronic products--Part 1:General and guidance (idt IEC 60068-1:1988)
GB 2423.39-1990 Basic environmental testing procedures for electric and electronic products Test Ee: Bounce
GB/T 2298-1991 Mechanical vibration and shock—Terminology (neq, ISO 2041-1990)
3 General
For the purposes of this document, the terms and definitions used in GB/T 2298-1991 and GB/T 2423 apply.
3.1
package
result of the packing operation, consisting of the packaging and its contents, for example, electronic devices prepared for transport
3.2
packaging
product made of any material of any nature to be used for the containment, protection, handling and delivery, for example, a corrugated fibreboard box
4 General
The relevant specification shall state whether the effect of gravitational force is important. If so, the specimen shall be mounted in such a way that the gravitational force acts in the same direction as it would in use. Where the effect of gravitational force is not important, the specimen may be mounted in any attitude.
If significant for the test results, the relevant specification shall also state
a) the temperature limits within which the specimen shall be tested,
b) the maximum level of magnetic interference which may be imposed on the specimen and/or the orientation of the specimen in relation to the direction of the magnetic field (for example, near an electrodynamic vibration generator),
c) the relative humidity limits within which the specimen shall be tested.
5 Mounting, where the specimen is a component
The mounting method to be used shall be as stated in the relevant specification.
Foreword i
Introduction i
1 Scope
2 Normative References
3 General
4 General
5 Mounting, where the specimen is a component
6 Mounting, where the specimen is equipment and other articles
7 Mounting, where the specimen is a packaged product
8 Information to be given in the relevant specification
Annex A (informative) General Guidance
A.5 Balancing
A.6 Positioning of accelerometers
A.7 Performance check of test fixture
A.8 Large and/or complex specimens
Annex B (informative) Guidance on packaged products
B.1 General
B.2 Mounting – Packaging available
B.3 Mounting – Packaging not available
B.4 Dynamic conditions
Annex C (informative) Response of a Single Degree Of Freedom (SDOF) System To a Half-sine Shock Pulse
C.1 General
C.2 Specimen response
C.3 Peak amplitudes
C.4 Calculation of initial peak amplitude
C.5 Secondary responses
C.6 Pulse duration
C.7 Worked example
Figure 1 Examples of obvious means of mounting components
Figure 2 Examples of mounting of components by the leads only
Figure 3 Examples of mounting of components by the body only
Figure 4 Examples of mounting of components by the body and the leads
Figure 5 Examples of mounting of electronic cabinets
Figure B.1 Generalized transmissibility factors for packaging materials
Figure C.1 Typical characteristics of half sine pulse
Figure C.2 Typical single degree of freedom (SDOF) transmissibility characteristics
Figure C.3 Peak Acceleration Responses SRS
Figure C.4 Relative Amplitude of Secondary Response Peaks
Figure C.5 Notation of Response Characteristics
