A thermal shock chamber alternates hot and cold cycles to reproduce the physical and chemical changes a product undergoes in different environments. The results are used to judge reliability and performance and to guide design improvements. On this kind of equipment, a few operating details decide both the validity of the test and the service life of the chamber.
Check the door seal before the test
Before starting, make sure the door is closed and seated properly, so that air leaks do not distort the results. Do not open and close the door repeatedly during a run — it degrades chamber performance and shortens the working life of the machine.
Limit door openings in low-temperature tests
Below 0°C, keep door openings as short as possible and close the door immediately afterwards. Once the door is open, cold air escapes and frost forms on the chamber; the lower the temperature, the more pronounced this becomes.
For long low-temperature programmes, defrost on a schedule. After completing one cycle, set the chamber to 110°C, open the door slightly, and run for two hours.
What must stay out of the chamber and away from it
Do not place corrosive, flammable or explosive materials around or inside the chamber — they can damage the equipment. If the chamber is left idle for long periods, power it up once every two weeks and check that its components are working normally.
Wrapping up after a test
Follow the operating procedure strictly. When the test is finished, set the temperature back to ambient, let the chamber run for half an hour, then switch off the power and wipe down the inner walls.