The constant temperature and humidity chamber is used to determine the adaptability of products and materials for storage and use under low temperature environmental conditions caused by temperature cycling changes. For the recovery of the sample after the end of the test in the constant temperature and humidity test chamber, put the test sample with room temperature into the test chamber with the temperature specified by the relevant specifications, which meets the severe level. After the sample has reached temperature stabilization, it is exposed for the specified duration under that condition.
As the constant temperature and humidity chamber is used more and more frequently, some manufacturers do not understand some problems when they try the equipment for the first time. Let us introduce to you how to recover the samples after the test in the constant temperature and humidity test chamber.
The work that should be done after the test of the constant temperature and humidity test chamber: intermediate inspection, recovery, final inspection, and the information given in the relevant specifications are listed below.
The relevant specifications may propose that the test samples remain in the constant temperature and humidity chamber for testing during or at the end of the conditional test. If such testing is required, the relevant specifications should specify the items to be tested and the time to complete these measurements. When testing, the test sample should not be taken out of the chamber.
The relevant specifications stipulate whether the samples after the test should be recovered under standard atmospheric conditions or under specific conditions. If the samples need to be recovered under specific conditions, the samples should be moved to another constant temperature and humidity chamber or still in the original test chamber. If the sample needs to be transferred to another test chamber for recovery, the time for transferring the sample should be as short as possible. If it is left in the test chamber for recovery, the relative humidity should be reduced to 73% to 77%. And then adjust the temperature to the temperature of the laboratory within 0.5h, and the temperature tolerance is +1K. According to the relevant specifications, the recovery time should be calculated from the time when the recovery conditions are met.
According to the relevant specifications, the appearance of the test sample is tested, and its electrical and mechanical properties are tested.
When the relevant specification adopts this test method, specific provisions shall be made for the following items:
a. Installation of test samples;
b. Severity level and duration of the test: temperature, relative humidity, duration;
c. Initial inspection;
d. Conditional test;
e. Intermediate inspection;
g. Final inspection.
1. The test samples should be recovered under standard atmospheric conditions until thawed.
2. In order to remove water droplets, shake the test sample by hand, or blow air at room temperature for a short time.
3. When the test sample is recovered under standard atmospheric conditions, the recovery time should be sufficient to make the temperature stabilize, at least 1h. When several samples are tested at the same time, and the recovery time of 1h is sufficient, the longest recovery time is 2h, which means all measurements must be completed before this time.
4. If it is required by relevant specifications, we should energize or load the test sample during the recovery period, and measure its performance continuously.
5. When the standard atmospheric conditions are not suitable for the test samples, other recovery conditions may be specified in the relevant specifications.