GB/T 2423.42-1995 Environmental testing for electrical and electronic products - Low temperature/low pressure/vibration (sinusoidal) comprehensive test method
Some standard content:
National Standard of the People's Republic of China
Environmental testing for electric and electronic products
Low temperature/low air pressure/vibration (sinusoidal)
Comprehensive test method
Basic environmental testing proceduresfor electric and electronic productsCombined iow temperature /low air pressure/vibration(sinusoidal)test1Subject content and scope of application
GB/T2423.42-1995
This standard specifies the basic requirements, severity levels, test procedures and other technical details of the low temperature/low air pressure/vibration (sinusoidal) comprehensive test.
This standard is applicable to determine the adaptability of the product to storage, transportation and use under the simultaneous action of low temperature, low air pressure and vibration (sinusoidal). 2 Reference standards
GB2421 General rules for basic environmental testing procedures for electric and electronic products GB2422 Glossary of terms for basic environmental testing procedures for electric and electronic products GB2423.1 Basic environmental testing procedures for electric and electronic products Test A: Low temperature test method GB2423.10 Basic environmental testing procedures for electric and electronic products Test Fc: Vibration (sinusoidal) test method GB2423.21 Basic environmental testing procedures for electric and electronic products Test M: Low pressure test method 3 General description
This test is a comprehensive test of test A: low temperature, test M: low pressure and test Fc: vibration (sinusoidal). The test sample should be subjected to vibration test, low temperature test and low temperature/low pressure comprehensive test at laboratory temperature in sequence according to the test procedure, and finally superimposed with vibration (sinusoidal) to make the test sample undergo low temperature/low pressure/vibration (sinusoidal) comprehensive test. Whether the test sample is in working state during the test should be specified by the relevant standards. The test procedure is shown in Figures 1 and 2. When the test sample has passed the single vibration (sine) test, low temperature test and low temperature/low pressure comprehensive test, the low temperature/low pressure/vibration (sine) comprehensive test can be carried out directly. 4 Test equipment
The test equipment shall meet the conditions specified in GB2423.1, GB2423.2 and GB2423.10. However, the requirements for the box wall during temperature and pressure changes do not apply.
Care should be taken to avoid mechanical coupling between the vibration table and the test box (room) and air inhaled when the pressure returns to normal atmospheric pressure to pollute the air in the test box (room).
Approved by the State Administration of Technical Supervision on January 27, 1995 398
Implemented on December 1, 1995
5 Installation of test samples
GB/T 2423.42--1995
The installation of test samples shall meet the installation requirements of GB2423.1 and GB2423.10. For the test of heat dissipation test samples, the insulation pad between the test sample and the vibration table shall have large rigidity and low thermal conductivity (insulation). 6 Severity level
The severity level of the test is determined by temperature, air pressure, vibration frequency range, amplitude value and duration. The relevant standards may preferentially select temperature, air pressure, vibration frequency range, amplitude value and duration from the following values for test level combination.
Temperature (see Table 1)
Temperature value
Note: When the air pressure is lower than 10 kPa and it is difficult to achieve the specified temperature tolerance, the relevant standards may specify additional tolerances. 6.2 Air pressure (see Table 2)
6.3 Frequency range (see Table 3)
Preferred frequency range
Approximate altitude
1~35(40),1100,2-80,10~55,10100(110)10~150,10~~200,10～500,102000.105000,55~500,55~2000,55~~5000,100~~2000390
6.4 Amplitude value
GB/T 2423-42
—1995
Preferred value of the amplitude value at low crossover frequency (8~9Hz) (see Table 4). Table 4
Displacement amplitude below the crossover frequency
Note: ①The data listed in the table are all peak values. Acceleration amplitude above the crossover frequency
②When the crossover frequency of 8 to 9 Hz is not technically applicable, the relevant standards may specify the crossover frequency and its corresponding displacement and acceleration amplitudes. b.
Preferred values of amplitude values at high crossover frequencies (57 to 62 Hz) (see Table 5). Table 5
Displacement amplitude below the crossover frequency
Note: ①The data listed in Table 5 are all peak values. Acceleration amplitude above the crossover frequency
②When the crossover frequency of 57 to 62 Hz is not technically applicable, the relevant standards may specify the crossover frequency and its corresponding displacement and acceleration amplitudes.
6.5 Duration of conditional test
The duration of conditional test shall be calculated from the time when the test sample reaches temperature stability and starts to vibrate under low temperature and low pressure conditions (see Figures 1 and 2).
6.5.1 Duration of frequency sweep vibration test under low temperature and low pressure combined environmental conditions The test time on each axis is given as the number of frequency sweep cycles: 100
1, 2, 5, 15, 20, 50, 100.
2—1995
GB/T 2423.42
6.5.2 Duration of fixed frequency vibration test under low temperature and low pressure combined environmental conditions a. At dangerous frequencies
The test duration at each dangerous frequency (obtained from vibration response check) in each axis: 10, 30, 60, 90, 120, 600 min.
b. At the predetermined frequency
In order to determine the cumulative effect of the test sample to the comprehensive environment (low temperature, low pressure and vibration), a 10° cycle test should be carried out on the predetermined frequency on each specified axis.
7 Pretreatment
The test sample should be pretreated in accordance with the relevant standards. 8 Initial inspection
The test sample should be inspected for appearance and tested for electrical and mechanical properties in accordance with the relevant standards. 9 Conditioning test
The relevant standards should specify that the test sample should be vibrated on one or several axes. When vibration is specified on several axes during the entire conditional test, the entire test procedure should be repeated on each specified axis. The heat dissipation test sample should adopt the test method without forced air circulation in Test Ad of GB2423.1. For heat dissipation test samples without cooling devices, when the test box (room) is large enough, but only forced air circulation can maintain the test temperature in the box (room), method A in Test Ad can be used. When the volume of the test box is too small to meet the free air condition, method B in Test Ad should be used. For heat dissipation test samples with cooling devices, method A in test Ad can be used. However, the relevant standards should specify the characteristics of the supplied coolant. If it is air, it should be free from oil contamination and moisture. For non-heat dissipation test samples, the test method of forced air circulation should be used. 9.1 Vibration test
9.1.1 The comprehensive test box (room) is at the test room temperature. The test sample is installed on the vibration table according to the specified axis when it is not packaged, not powered, and in the "preparation" state, and then the vibration test is carried out according to the severity level specified in the relevant standards. When it is necessary to determine the dangerous frequency of the test sample, a vibration response check of a frequency sweep cycle should be carried out within the specified frequency range. 9.1.2 When required by the relevant standards, the test sample shall be subjected to performance testing. 9.2 Low temperature test
9.2.1 The test sample shall remain installed as during the vibration test. 9.2.2 The temperature in the test box (room) shall be adjusted to the value specified in the relevant standards and the test sample shall reach temperature stability. The average rate of temperature change in the test box (room) is: 0.7~1℃/min (the average rate is calculated every 5 minutes). 9.2.3 When required by the relevant standards, the test sample shall be subjected to performance testing . 9.3 Low temperature/low air pressure comprehensive test
9.3.1 Following 9.2.3, the air pressure in the test box (room) is reduced to the value specified in the relevant standards, and the air pressure change rate should not be greater than 10kPa/min or as specified in the relevant standards.
9.3.2 After the temperature and air pressure reach the values specified in the relevant standards and stabilize, when the relevant standards require, the test samples are subjected to performance testing. 9.4 Low temperature/low air pressure/vibration comprehensive test
9.4.1 After the temperature and air pressure reach the specified values and stabilize, a vibration test is carried out according to the severity level specified in the relevant standards. When it is necessary to determine the dangerous frequency of the test sample, a vibration response check of a frequency sweep cycle should be carried out within the specified frequency range. The temperature and air pressure should remain unchanged for the specified duration.
9.4.2 Intermediate testing should be completed in the shortest possible time before the end of the conditional test. 401
GB/T2423.42—1995
9.4.3 Vibration should be stopped at the end of the conditional test, and the test samples running (or working) during the conditional test should be powered off or unloaded. The air pressure in the test box (room) is restored to normal atmospheric pressure at a rate not exceeding 10kPa/min. During the pressurization period, temperature control is not required, and the test samples should be kept in the test box (room). The temperature in the test box (room) is increased to normal test atmospheric conditions at a rate not exceeding 1℃/min (calculated at an average rate every 5 minutes). Thereafter, the test samples are restored in the test box (room) in accordance with the relevant standards. 10 Intermediate test
See GB 2423.1
11 Restoration
See GB2423.1
12 Final test
Perform visual inspection and electrical and mechanical performance tests on the test samples according to the relevant standards. 13 Failure criterion
Failure criterion shall be specified by the relevant standards.
14 Detailed rules to be specified when this test method is adopted When the relevant standards adopt this test method, specific provisions shall be made for the following items. a.
Pretreatment, see Chapter 7;
Initial inspection, see Chapter 8;
Installation of test samples, see Chapter 5;
State of test samples and precautions, see Chapter 9; Severity level, see Chapter 6;
Vibration axis, see Chapter 9;
Vibration method (fixed frequency test method or sweep frequency test method), see Chapter 9; Tests to be performed during vibration test, see Article 9.1.2, tests to be performed during low temperature test, see Article 9.2.3; tests to be performed during low temperature/low pressure combined test, see Article 9.3.2; intermediate inspection, see Chapter 10;
Load conditions during recovery, see Chapter 11; final inspection, see Chapter 12;
Failure criteria, see Chapter 13.
There are American clauses
Laboratory temperature
Specified
Test temperature
Laboratory air pressure
Specified
Test air pressure
4. Appearance and performance
Performance testing
Initial testing
777777
Note: * in the figure indicates intermediate testing.
GB/T2423.42--1995
Conditional test
4,3.2. 9. 4.1, 9.4.2
Test sample temperature
Test duration
Figure 1 Test curve of non-heat dissipation test sample
Final test
Related provisions
Test case temperature
Specifiedwww.bzxz.net
Test temperature
Test room pressure
Specified
Test pressure
4. Test sample
Product energization
5. Appearance and performance
Test initial test
Note: * in the figure is the intermediate test.
Additional Notes:
GB/T2423.42--1995
Conditional Test
4.3.2, 9. 4. 1.9. 4.2
Test Sample Temperature
Test Duration
Relevant standards may require that the test sample is not powered*
Figure 2 Test curve of heat dissipation test sample
This standard is proposed by the Ministry of Posts and Telecommunications of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Environmental Technology Standardization of Electrical and Electronic Products. This standard was drafted by the Guangdong Post and Telecommunications Science Research Institute. The main drafters of this standard are Chen Jianer, Liang Xiaobing, Han Zhiqiang, Wang Shurong, and Wei Bei. 104
Final Test
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