The testing method of the two box type cold and hot shock test box usually includes five key steps: pretreatment, initial detection, testing stage, recovery stage, and final detection. The following are the specific operating steps and key points:
Preprocessing: Place the sample to be tested under normal atmospheric conditions until its temperature reaches a stable state. This step ensures that the sample is in an environmentally balanced state before entering the test chamber, avoiding the influence of initial temperature differences on the test results.
Initial testing: Compare the preprocessed sample with the test standard requirements to ensure that the sample meets the testing requirements, and then place the sample that meets the requirements into the testing area of the test chamber.
Experimental phase:
High temperature test: Set the temperature inside the test chamber to the designated high temperature point and maintain it for a period of time until the sample reaches temperature stability. The holding time may vary depending on the sample size and space size.
Quickly switch to low temperature: After the high temperature stage is completed, the temperature inside the test chamber is usually quickly switched to the designated low temperature point (e.g. -55 ℃) within 5 minutes, and maintained for a period of time (e.g. 1 hour) until the sample reaches temperature stability.
Quickly switch to high temperature: After the low temperature stage is completed, within 5 minutes, quickly switch the temperature inside the test chamber back to the high temperature point (such as 70 ℃) and maintain it for a period of time until the sample reaches temperature stability again.
Cycle testing: According to testing standards or product requirements, repeat the above high and low temperature impact testing cycles, usually completing three or more cycles.
Recovery phase:
Take out the sample: After completing all cycle tests, take out the sample from the test chamber.
Temperature recovery: Place the sample under normal atmospheric conditions for a period of time (such as 2 hours) until its temperature returns to a stable state.
Final inspection:
Evaluate test results: Based on testing standards or product requirements, evaluate the degree of damage or conduct other relevant tests on the restored samples.
Recording and Analysis: Record test results and compare them with standard requirements to analyze whether the sample meets the requirements.
Precautions for operation:
Equipment maintenance: Regularly inspect and maintain the test chamber to ensure its normal operation and accuracy. For example, defrosting operations can be performed based on the device's operating cycle to prevent frost buildup inside the low-temperature chamber from affecting the cooling effect.
Parameter adjustment: Depending on different testing requirements and sample characteristics, it may be necessary to adjust testing parameters (such as temperature, time, etc.).
Safe operation: When conducting cold and hot shock tests, ensure that the door of the test chamber is tightly closed to prevent temperature fluctuations. Meanwhile, the tested items are not allowed to be flammable, explosive, or highly volatile to ensure the safety of the testing environment.