GB 2423.20-1981 Basic environmental testing procedures for electrical and electronic products Test Kd: Hydrogen sulfide test method for contact points and connectors GB2423.20-1981 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Basic Environmental Testing Procedures for Electrical and Electronic Products Test Kd: Hydrogen Sulfide Test Method for Contacts and Connectors
GB 2423.20—81
This standard provides accelerated test methods to evaluate the effect of discoloration of silver and silver alloys used for contacts and connectors. This test method is particularly suitable for comparative tests. This test method cannot be used as a general corrosion test, that is, it cannot predict the corrosion resistance of contacts and connectors in industrial atmospheres.
2 Purpose
2.1 Determine the effect of atmospheres containing hydrogen sulfide on the contact characteristics of contacts and connectors made of the following materials. Silver or silver alloy;
Silver with other protective layers;
Metal covered with silver or silver alloy
2.2 Check the tightness and effectiveness of wrapped or rolled connectors made of the above materials. In all tests, the performance is evaluated mainly based on the change in contact resistance caused by exposure of the test specimens to the sulfur-containing atmosphere.
3 Test Chamber
The materials used in the test chamber and its accessories shall not react with or absorb hydrogen sulfide and shall not affect the corrosive effect of the test gas. The gas pipelines entering and exiting the test chamber shall be large enough so that the total flow of gas passing through the chamber is changed 3 to 5 times per hour. The gas discharged from the test chamber is not allowed to enter the laboratory.
The structure of the test chamber and the method of generating the test gas shall meet the following requirements: a. The conditions in the effective space where the test sample is placed in the test chamber shall be within the specified range; b. The test sample shall not be directly subjected to the impact of the incoming air flow; c. The average relative speed of the test gas to the test sample shall be 20 to 60 m/h (about 6 to 17 mm/s) or a stirring device shall be used to make the relative speed between the test gas and the test sample similar; d. Condensation is not allowed on the inner wall of the test chamber; e. The test chamber shall not be directly exposed to sunlight, and the illuminance (generated by daylight or incandescent or fluorescent lamps) measured on any exposed surface in the test chamber shall be in the range of 50 to 300 lux. See the Appendix for a schematic diagram of the test equipment.
4 Test gas
4.1 The composition of the gas in the test chamber must meet the following conditions: Hydrogen sulfide 10~15ppm (volume ratio)
Temperature 25±2℃
General Administration of Standards of the People's Republic of China
National Technical Committee for Environmental Standardization of Electrical and Electronic Products
April 1, 1982
National Technical Committee for Environmental Standardization of Electrical and Electronic Products Working Group 4www.bzxz.net
Relative humidity 75±5%
4.2 Obtaining test gas
GB 2423.20-81
Use a method that can ensure the acquisition of a uniform mixture to mix hydrogen sulfide and water vapor in a certain amount of air to obtain the test gas (to obtain a mixed gas with a uniform distribution of hydrogen sulfide, it may be necessary to mix in steps). 5 Initial testing
5.1 The test samples during the test cannot be cleaned. (Unless otherwise specified in the relevant standards or otherwise agreed by the relevant parties). 5.2 The relevant standards may require that the resistance measurement before and after the test should be combined with mechanical tests (such as impact or vibration tests).
5.3 The test samples should be measured, mechanically inspected and mechanically tested for durability in accordance with the requirements of the relevant standards: 5.4 The contact resistance should be measured using the low open circuit voltage method to avoid damaging the film formed on the contact surface. 6 Conditioning test
6.1 Before the start of the conditioning test, the concentration of hydrogen sulfide, temperature and relative humidity must be measured, and the test should be started when the test conditions reach stability. During the test, regular checks must be made to ensure that these conditions meet the test requirements. 6.2 It should be noted that the test samples should not be in contact with each other when placed and should not block the test gas from each other. 6.3 Full attention must be paid to the contact points not being disturbed during the conditioning process. 6.4 When the test samples are exposed, the contact points should be opened or closed as specified in the relevant standards. 6.5 Whether the test sample is loaded or operated (.T. operation) shall be specified in the relevant standards. 6.6 The test sample is continuously exposed for the time specified in the relevant standards, preferably for 4, 10 or 21 days. 7 Final test
7.1 After the test sample is taken out of the box and stored under standard recovery conditions for 1 to 2 hours, the contact resistance is measured. Pay attention to ensure that the contact points are not disturbed. The contact resistance is measured using the same test method as the initial test. Note: If the necessary test cannot be carried out within the specified time, the storage time under standard recovery conditions can be extended to a maximum of 24 hours. However, this extension time must be stated in the report.
7.2 Generally speaking, when the test sample is exposed with the contact points closed, the contact resistance must be measured before opening. When the test sample is exposed with the contact points open, the contact points must be closed once and then the contact resistance is measured. 7.3 The contact point treatment and measurement steps before the final test must be carried out in accordance with the requirements of the relevant standards. The relevant standards may require the appearance inspection of the test sample. 8 When the relevant standards adopt this test method, the following items must be clearly specified: a. Measurement, inspection and mechanical durability test before the conditional test. See Section 5.3 b. The state of the contact point during the conditional test, that is, closed or open. See Section 6.4
C. Whether the test sample is loaded or running (working) during the conditional test. See Section 6.5 d. Conditional test cycle (days).
See Section 6.6
e. Performance test and appearance inspection to be carried out at the end of the test. ! See Section 7.3
G2423.20-81
Device for generating test gas
This appendix briefly describes a device for generating test gas by directly mixing a fixed component. Other mixing and control methods and devices may also be used as long as they meet all the requirements of this standard. This test equipment is shown in Figure 1 and consists of the following parts: air conditioning, air pump, test box, gas washing bottle (to remove H, S in the exhaust gas), flow meter and vacuum pump. The corrosive gas is mixed with the (temperature-controlled and condensed) air from the air conditioning part through the pressure reducing valve, pump and spray. In the test box, the gas is mixed and evenly mixed through the buffer plate. The test gas is discharged from the box through the gas washing bottle for removing corrosive gas by the vacuum pump, and a condensing coil is inserted between the gas washing bottle and the vacuum pump. The gas flow rate should be adjusted to the specified value and the gas flow rate is measured by a gas flow meter.
The hydrogen sulfide concentration in the box must be checked regularly by any familiar analytical method. Suction pump and condensing coil
Gas flow meter
Upper gas washing bottle
Insulation material
Heating and (or)
Cooling device
A buffer plate
Pressure valve
Corrosive gas spray
Filter
Gas source
Air conditioning device
Attached figure Schematic diagram of test equipment with test gas generating device 929
1. This standard should be used together with the following standards: GB2423.20-81
GB242181 "General Principles of Basic Environmental Test Procedures for Electric and Electronic Products" GB2422--81 "Terms and Terms of Basic Environmental Test Procedures for Electric and Electronic Products" GB242410--81 "General Guidelines for Accelerated Atmospheric Corrosion Tests of Basic Environmental Test Procedures for Electric and Electronic Products" 2. This standard directly quotes the International Electrotechnical Commission Standard Publication 68--2--43, 1976 First Edition, Test Kd: Hydrogen Sulphide Test for Contacts and Connections (IEC Standard, Publication 68--2--43, 1976 First Edition, Test Kd: Hydrogen Sulphide test for contacts and connections), but the text and layout have been changed. 230
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