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.
Generally, test applications are divided into the Low Temperature Storage Test and Low Temperature Operating Test. It is recommended to undertake a cold start test in low temperature testing to verify if the test object can startup in low temperature. From experience, most products fail to operate in cold temperatures. If the product is tested using low voltage during cold temperature testing, the results will be even better.
The usual effects of low temperatures are unable to startup, material cracking, glass products becoming fragile, jamming of movable parts, changes in lubrication, and so on.