Structural Composition of Infrared Radiation Detector
(1) The optical system is mainly used to generate infrared light within a certain wavelength range. The optical system is composed of a light source and a lens. Different light sources have different radiation capabilities. Different radiation densities can be obtained by choosing different radiation sources.
(2) Depending on the material, the lens selectively transmits infrared light within a certain range of wavelengths, while absorbing infrared light within other wavelength ranges. The combination of the two can make the optical system generate infrared light within a certain wavelength range. Generally, optical glass and quartz materials allow infrared light from 0.75 to 3 μm to pass through; hot-pressed optical materials such as magnesium fluoride and magnesium oxide, The infrared light of 3-5 μm is allowed to pass through; the infrared light of 5-14 μm can easily penetrate optical materials such as germanium, silicon, and hot-pressed zinc sulfide. These materials provide convenience for determining λm, and lay the material foundation for using different radiation lights to form various infrared radiators.
(3) There are two main types of infrared receivers:
① Heat-sensitive products. Use a thermistor to receive infrared radiation. The resistance change caused by the thermal effect converts the infrared radiation energy into an electrical signal.
② Optoelectronics. The use of photoelectric components to receive infrared radiation produces a photoelectric effect, thereby converting infrared radiation energy into electrical signals. The photoelectric effect is much faster than the thermal effect, because the response time of the photoelectric sensor is much shorter than that of the thermal sensor. The heat-sensitive type can absorb all radiation energy of any wavelength, while the photoelectric type has a wavelength limit.
According to the three basic laws of radiation and various measurement objects, different optical systems and infrared receivers can be selected, and various infrared optical temperature measurement sensor systems can be formed according to specific conditions.
