The principle of infrared thermometer is that in nature, in addition to the light visible to the human eye (usually called visible light), there are ultraviolet, infrared and other non-visible light. Any object in nature with a temperature higher than absolute zero (-273 ° C), at any time to the outside world to radiate electromagnetic waves (infrared), so infrared is the existence of the most extensive electromagnetic waves in nature, and thermal infrared will not be absorbed by the atmospheric smoke cloud. With the rapid changes in science and technology, the use of infrared this characteristic, using the combination of applied electronics and computer software and infrared technology, used to detect and measure thermal radiation. The size of the surface of the object to radiate heat externally, heat-sensitive sensors to obtain different heat difference, through the processing of electronic technology and software technology, presenting a dark and light or color difference between the images, that is, we usually say that infrared thermal imaging; will be radiated by the source of surface heat through the thermal radiation algorithm algorithm conversion, the realization of the thermal image of the conversion between the temperature.