The procedure for digital communication equipment to do low temperature work tests:
Pretreatment: Place the test sample under normal test atmospheric conditions until temperature stability is reached.
Initial testing: Prior to any environmental testing, the test sample shall be subjected to electrical, mechanical, and other performance measurements and visual inspections under normal atmospheric conditions of the test, and test data shall be recorded.
Test: The test sample is placed in the low temperature test chamber as required, and then cooled to the lowest working ambient temperature of the test sample and remains unchanged until the temperature is stable. Then start the work until the test sample reaches the temperature stability or the working time specified by the product standard (or technical documents), and carry out the intermediate test. The test items and requirements are specified by the product standard (or technical documents).
Recovery: The test sample is stopped and returned to normal test atmospheric conditions in the test chamber at a rate of temperature change not exceeding 10 ° C / min until the temperature of the test sample is stable.
Final test: After the recovery period is over, the test sample shall be measured and visually inspected for electrical, mechanical and other properties as specified in the equipment product standard (or technical documentation) and compared with the initial test data.
Test interruption treatment: When an unexpected test interruption occurs, it should generally be handled in accordance with the provisions of 2.6. If other methods are used, it should be explained in the test report.
Qualification criteria: as specified by product standards (or technical documents).
Note: The above procedures for low temperature work test are carried out in accordance with the requirements of Standard GB/T 13543-1992 "Digital Communication Equipment Environmental Test Methods".
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