Temperature Testing Practices

Many items require thermal environmental testing. Items going through product development, requiring validation for high-reliability applications, and products exposed to extreme environments among others require specific thermal testing.

Diligent adherence to requirements results in performing a meaningful test and ultimately higher quality products as opposed to simply taking the easiest route to put a testing checkmark in the box.

A few important aspects of the testing can help ensure that best practices in thermal testing are followed to get real results from testing efforts.

1. Testing can be time-consuming.  Properly applied automation will increase repeatability and can produce consistent results. Test results can be automatically stored on the test equipment, in the cloud, or automatically printed to a network printer.
2. Automation also reduces some unexpected uncertainties in the testing such as reducing the temptation to open the door/lid of the chamber during the test.  In addition to disturbing the temperature uniformity of the test, if cool air is introduced when the system is at extreme hot or cold temperatures, moist air can result in unwanted condensation or corrosion on the devices being tested.
3. Best heat transfer will get the job done most effectively.  When possible conductive heat transfer will achieve the setpoint in less time with less energy.  When heat transfer by conduction is not possible or practical a convection chamber or a hybrid combining conduction and convection is a good idea.
4. When using a temperature chamber, for best heat transfer, be sure that airflow across the device is as great as possible to transfer heat effectively as possible.
5. Use of secondary sensor(s) in a chamber or thermal platform can be applied to either verify that critical zones in the product to be tested actually achieve the specified or with a controller that employs smarter temperature control algorithms which can consider both the system temperature and individual device under test (DUT) temperature.
6. Prior to purchase, always give plenty of consideration to the most preferred cooling method given the testing requirements and facilities available.