Low Temperature Environment Test of Electronic Instruments – Part 2
3.3 Test Requirements and Methods (1) During the temperature test, the temperature change speed between each temperature step shall not exceed 20 ℃ /h. During the test, the relevant test can be carried out only after the tested instrument reaches the temperature stable state as far as possible. (2) During the high and low temperature storage test of some instruments, the power supply should be disconnected. The power supply shall be kept in the test chamber for at least 4 h. (3) During the relevant temperature test, the temperature in the test chamber shall be kept as uniform and constant as possible. And the temperature difference shall be less than ± 2 ℃. At the same time, the volume of the test chamber shall be at least 3 times that of the tested instrument. During this test, relevant measures shall be taken to avoid the influence of humidity on the test. (4) During the temperature test of relevant instruments, it is necessary to carry out the temperature cycle tes...