Infrared thermal imager is a kind of equipment that converts the image of temperature distribution of the subject matter into visual image by means of infrared radiation detection of the subject matter and signal processing, photoelectric conversion and other means by using infrared thermal imaging technology. Infrared thermal imager is usually composed of optical unit, focusing/doubling component, internal non-uniformity correction component, imaging circuit component and infrared detector/refrigerator component. Widely used in scientific research field, medical field, electronics and other industries.