In most areas, the average temperature is around 0°C~40°C, and during the winter, the temperature is around -32°C~-46°C. Chances of temperatures being under -51°C is less than 20%. The environmental setting of consumer electronics are usually between +5°C~ -5°C; telecommunication products and industrial product, due to life expectation, usually are between-5°C~-20°C. For products exposed to a long period in an outdoor environment (e.g. LED street lights), a lower limitation shall be set for the low-temperature, say -30°C or -40°C for adequate accuracy to be obtained.

To precisely inspect and verify the product’s performance under cold temperature conditions, International Electrotechnical Commission (IEC) has standards for preconditioning, post testing conditioning, temperature rising speed, constant temperature definition, temperature load condition, unit under testing and chamber volume ratio and so on.