Spacechina

Frost formation in a thermal shock test chamber is a sublimation phenomenon where moisture inside the chamber condenses under low-temperature conditions. But why does this happen? Is it simply because the chamber temperature is too low?

In the field of environmental reliability testing, thermal shock test chambers are widely used to evaluate the adaptability and lifetime degradation of electronic components, materials, and complete products under rapid and extreme temperature transients.

Given that temperature and humidity alternating test chambers are expensive, it is crucial to keep certain precautions in mind when using the equipment to ensure better protection and maximize its value.

A thermal-shock chamber (TSC) is not an off-the-shelf climatic box. Its only purpose is to generate controlled temperature gradients and rapid transfer rates that reveal thermo-mechanical defects. A poor choice will distort test data, delay R&D, fail certification audits, or even trigger a product recall. This paper translates field experience into an engineering checklist for R&D, Quality and ESS engineers.

The humidification process in a constant temperature and humidity test chamber essentially involves increasing the water vapor partial pressure. The initial humidification method was to spray water onto the chamber walls and control the water temperature to regulate the saturation pressure of the water surface.