What is Hot and Cold Thermal Shock Test?

The hot and cold shock test, also known as the temperature thermal shock test or the iqualitrol high and low temperature shock test, is used to assess the adaptability of the product to the rapid change of the ambient temperature.

It is an indispensable test in the identification test of the equipment design and the routine test in the batch production stage.

In some cases, it can also be used for environmental stress screening test. It can be said that the frequency of application of the hot and cold shock test chamber in verifying and improving the environmental adaptability of the equipment is second only to vibration and high and low temperature tests.

The chemical changes or physical damages produced in the hot and cold shock test are caused by changes in thermal expansion and contraction or other physical values.

The effects of the hot and cold shock test include electrochemical changes caused by cracking or breaking of the finished product and displacement.

For example, some metal materials such as medium and low strength steel with body-centered cubic lattice, when their service temperature is reduced, the plasticity and toughness will decrease sharply, making the material brittle.

Analysis of Common Reasons for Product Failure

• Extreme temperature rise causes solder reflow;

• When the motor is started, the temperature of the surrounding components rises rapidly, and when the motor is turned off, the temperature of the surrounding components drops suddenly;

• The equipment is moved from a high-temperature indoor environment to a relatively low-temperature outdoor environment, or from a relatively low-temperature outdoor environment to a high-temperature indoor environment;

• The equipment may be connected to the power supply in a low-temperature environment, resulting in a steep temperature gradient inside the equipment. Cutting off the power supply in a low-temperature environment may cause a steep temperature gradient in the opposite direction inside the equipment;

• The equipment may suddenly cool down due to rainfall;

• When the aircraft takes off or lands, the temperature of the aircraft's external equipment may change dramatically, with a heating/cooling rate of not less than 30 ℃/min. The temperature change range is large, and the test severity increases with the increase in the temperature change rate.