This standard specifies the severity level, pretreatment, initial measurement, conditional test, recovery and final measurement of low pressure test methods for electrical and electronic products. This standard applies to low pressure tests under room temperature conditions. It is mainly used to determine the adaptability of parts, equipment or other products to storage, transportation or use under low pressure conditions. GB 2423.21-1991 Basic environmental test procedures for electrical and electronic products Test M: Low pressure test method GB2423.21-1991 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Basic environmental testing procedures for electric and electronic productsTest M,Low air pressure
GB 2423.21-91
Replaces GB2423.21--81
This standard adopts the International Electrotechnical Commission IEC68--2-13 "Basic Environmental Testing Procedures Part 2: Test Test M: Low Air Pressure" (1983 Edition).
1 Subject content and scope of application
This standard specifies the severity level, pretreatment, initial measurement, condition test, recovery and final measurement of the low air pressure test method for electric and electronic products.
This standard is applicable to low air pressure tests under room temperature conditions. It is mainly used to determine the adaptability of components, equipment or other products to storage, transportation or use under low air pressure conditions.
Note: For products under storage, transportation or use conditions, when the stress imposed on the product by high temperature and low pressure or the combined effect of low temperature and low pressure or the failure mechanism under this stress is very important, the test should be carried out in accordance with the following standards: GB2423.25 and GB2423.26. 2 Reference standards
GB2421
General provisions of basic environmental testing procedures for electric and electronic products 2 Basic environmental testing procedures for electric and electronic products Terminology GB2422
GB2423.2 5 Basic environmental test procedures for electric and electronic products Test Z/AM: Low temperature/low pressure comprehensive test method GB2423.26 Basic environmental test procedures for electric and electronic products Test Z/BM: High temperature/low pressure comprehensive test method Temperature/low pressure comprehensive test guide
GB2424.15 Basic environmental test procedures for electric and electronic products 3 General description
The low pressure test is to put the test sample into the test box (chamber), then reduce the pressure in the box (chamber) to the value specified in the relevant standards, and maintain the test for the specified duration.
4 Test equipment
4.1 The test box (chamber) should have the ability to maintain the low pressure conditions specified in Chapter 5 of this standard. 4.2 When restoring the air pressure to normal, care should be taken to avoid the air in the box from being polluted by auxiliary equipment and the introduction of unclean air.
4.3 When testing heat dissipation test samples, the requirements for the test box (chamber) can be appropriately specified according to GB2423.26. 5 Severity Level
5.1 The relevant standards shall specify the severity level of air pressure and test duration, and its value shall be selected from the provisions of Articles 5.2 and 5.3 of this standard. Approved by the State Administration of Technical Supervision on May 27, 1991 and implemented on February 1, 1992
5.2 Air Pressure
GB2423.21
The following pressures shall be maintained in the test box (room), with a tolerance of ±5% or ±0.1kPa (whichever is greater), and a tolerance of ±2kPa at the 84kPa level. As shown in the following table.
Test Air Pressure Tolerance
Note: ① Standard air pressures of 86kPa to 106kPa, including altitudes below 1000m. ②84kPa is applicable to tests where the test sample is required to be at a lower standard air pressure value. 5.3 Test duration
Relevant standards should give priority to the following test durations: 5 min
30 min
6 Pretreatment
Pretreatment may be specified in accordance with the requirements of relevant standards. 7 Initial measurement
The test samples shall be subjected to visual inspection and electrical and mechanical tests in accordance with the requirements of relevant standards. 8 Condition test
Approximate altitude
8.1 The temperature of the test chamber (room) shall be within the specified test standard atmospheric condition temperature range. For non-operating tests, the test samples shall be placed in the test chamber (room) in their normal position (unless otherwise specified) in an unpackaged, unpowered, "ready to use" state. 8.2 Reduce the air pressure in the test chamber (room) to a value that meets the specified severity level, with a pressure change rate of no more than 10kPa/min, or as specified in relevant standards.
8.3 During the operational test, the test sample shall be powered on or loaded with electrical load. It shall be checked to determine whether the test sample can meet the functions specified in the relevant standards. The test sample may be kept in the operating state for the specified duration, or the power supply may be disconnected as required in the relevant standards. If the relevant standards require intermediate measurements, intermediate measurements shall be carried out. 232bzxZ.net
GB 2423. 21 -- 91
For heat dissipation test samples, the relevant specifications may require that the test sample be powered on, and that sufficient time be allowed to stabilize before or after reducing the air pressure, and that functional tests and (or) measurements be carried out. 8.4 The air pressure shall be maintained for the specified duration. 8.5 The air pressure shall be restored to normal. If required by the relevant standards, the speed of air pressure change shall not exceed 10 kPa/min. 9 Recovery
If there are no other provisions in the relevant standards, the test sample shall be kept in the standard atmospheric conditions of the test for recovery for a period of not less than 1 hour, but not more than 2 hours.
10 Final measurement
The test samples shall be inspected visually and tested for electrical and mechanical properties in accordance with the requirements of the relevant standards. 11 Information to be given in the relevant standards
When applying this test method, the relevant standards shall give the following applicable details: pretreatment (see Chapter 6);
Initial test (see Chapter 7);
State of the test sample during conditioning (see Article 8.3); Severity level: test gas pressure and duration (see Chapter 5); Limitation on the rate of pressure change (see Article 8.2 or 8.5); Thermal stability measurement and (or) load check during conditioning test (see Article 8.1 or 8.3); Recovery (see Article 9);
Final measurement (see Article 10).
Additional notes:
This standard is proposed and managed by the National Technical Committee for Environmental Conditions and Environmental Tests for Electrical and Electronic Products. This standard was drafted by the Guangzhou Electric Science Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Xu Guobao, Zhu Yaochang and Zhang Leshan.
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