Infrared forehead temperature gun technical principle
All objects with a temperature above zero (-273.15 ° C) are constantly emitting infrared energy into the surrounding space. Its radiation characteristics, radiation energy size, wavelength distribution, etc. are closely related to the surface temperature of the object. Conversely, by measuring the infrared energy radiated by the object itself, it can accurately determine its surface temperature, which is the mechanism of infrared radiation temperature measurement.
The human body, like other organisms, radiates infrared energy to itself, and its wavelength is generally 9-13 μm, which is in the near infrared band of 0.76-100 μm. Because the light in this wavelength range is not absorbed by the air, that is to say, the infrared radiation of the human body has nothing to do with the environmental impact, but is related to the amount of energy contained and released by the human body. Therefore, as long as the infrared energy is radiated to the human body itself The measurement can accurately determine the surface temperature of the human body. The human body infrared temperature sensor is designed and manufactured based on this principle.
Infrared temperature sensor
According to different materials used for energy conversion, infrared temperature sensors on the market currently have the following types:
(1) Pyroelectric type: triglycol sulfate, lithium tantalate, etc.
(2) Thermopile type: N-type and P-type polysilicon
(3) Diode type: single crystal or polycrystalline PN junction
(4) Thermal capacitance type: Bi-material film
(5) Thermistor type: vanadium oxide, amorphous silicon, etc. In fact, these types are only after receiving infrared energy, the conversion method and the energy efficiency ratio of the material are different.