In nature, all objects with temperatures above absolute zero constantly emit infrared radiation energy into the surrounding space. The magnitude of an object's infrared radiation energy and its distribution along wavelength are closely related to its surface temperature. Therefore, by measuring the infrared energy radiated by an object itself, its surface temperature can be accurately determined; this is the objective basis for infrared radiation thermometry.
An infrared thermometer consists of an optical system, a photodetector, a signal amplifier, signal processing, and display output. The optical system focuses the infrared radiation energy of the target within its field of view; the size of the field of view is determined by the optical components and their positions. The infrared energy is focused onto the photodetector and converted into a corresponding electrical signal. This signal is amplified and processed by the signal processing circuit, and after correction according to the instrument's internal algorithm and target emissivity, it is converted into the temperature value of the target being measured. In addition, the environmental conditions of the target and the thermometer, such as temperature, atmosphere, pollution, and interference, should be considered, along with corresponding correction methods for these factors affecting performance indicators.
