Basic theory of infrared thermometer In 1672, it was discovered that the sunlight (white light) is composed of light of various colors. At the same time, Newton made the famous conclusion that monochromatic light is simpler in nature than white light. Using a spectroscopic prism, the sunlight (white light) is decomposed into red, orange, yellow, green, cyan, blue, and purple colors. In 1800, the British physicist FW Hegel discovered infrared rays when he studied various colors from the hot point of view. When studying the heat of various shades of light, he deliberately blocked the only window in the darkroom with a dark plate, and opened a rectangular hole in the plate, and installed a beam splitter prism in the hole. When the sunlight passes through the prism, it is decomposed into colored bands of light. The infrared thermometer uses a thermometer to measure the heat contained in the different colors of the band. In order to compare with the ambient temperature, Hessler used several thermometers placed near the colored light band as a comparison thermometer to measure the ambient temperature.
In the experiment, he stumbled upon a strange phenomenon: A thermometer placed outside the red light was higher than the other indoor temperature. After repeated experiments, this so-called high-temperature, high-temperature zone is always located outside the red light at the extreme edge of the strip. So he announced that in addition to visible light, the sun emits a kind of “hotline” that is invisible to the human eye. This invisible “hotline” is located outside the red light, called infrared light. Infrared is an electromagnetic wave and has the same essence as radio waves and visible light. The discovery of infrared rays is a leap of human understanding of nature, and it has opened up a whole new broad road for the research, utilization and development of infrared technology.
Infrared thermometer infrared wavelength between 0.76 ~ 100μm, according to the wavelength range can be divided into near-infrared, mid-infrared, far-infrared, far-infrared in four categories, its position in the electromagnetic spectrum is in the continuous wave radio and visible light The area between. Infrared radiation is one of the most widespread electromagnetic radiations in nature. It is based on the random movement of any molecule and atom that produces its own environment and constantly radiates out thermal infrared energy, movement of molecules and atoms. The more intense, the greater the energy of radiation, and conversely, the smaller the energy of radiation.
Objects whose absolute temperature is above zero will emit infrared rays due to their own molecular motion. After infrared thermometers convert the power signals radiated by objects into electric signals through infrared detectors, the output signals of the imaging device can completely simulate the spatial distribution of the surface temperature of the scanned objects, and are processed by the electronic system and transmitted to the display screen. Above, a thermal image corresponding to the heat distribution on the surface of the object is obtained. Using this method, we can achieve long-distance thermal state image imaging and temperature measurement and analysis and judgment.
