Infrared thermometer basic principle
In 1672, it was discovered that sunlight (white light) was a composite of various colors of light, and at the same time, Newton made the famous conclusion that monochromatic light was simpler in nature than white light. The use of spectroscopic prisms decomposed sunlight (white light) into red, orange, yellow, green, cyan, blue, violet and other colors of monochromatic light. 1800, the British physicist F. W. Herschel from the point of view of heat to study the various colors of light, the discovery of infrared light. When he studied the heat of various colors of light, he intentionally blocked the only window of a dark room with a dark board and opened a rectangular hole in the board, which contained a beam-splitting prism. When sunlight passed through the prism, it was broken up into bands of colored light, and a thermometer was used to measure the heat contained in the different colors of the bands. In order to compare with the ambient temperature, Herschel used several thermometers placed near the colored light bands as a comparison to determine the ambient temperature. During the experiment, he stumbled upon a strange phenomenon: a thermometer placed outside the red light of the light band had a higher value than the other temperatures indicated in the room. After repeated tests, this so-called heat the most high-temperature zone, is always located in the light band at the very edge of the outside of the red light. So he announced that the sun's radiation in addition to visible light, there is a human eye can not see the "hot line", this invisible "hot line" is located outside the red light, called infrared. Infrared is a kind of electromagnetic wave, with radio waves and visible light of the same nature, the discovery of infrared is a leap in human understanding of nature, research, use and development of infrared technology has opened up a new broad road.
Infrared wavelength between 0.76 ~ 100μm, according to the range of wavelengths can be divided into near-infrared, mid-infrared, far-infrared, far-infrared, very far-infrared four categories, which is in the continuous spectrum of electromagnetic waves in the position of the radio waves and the visible light in the region between. Infrared radiation is one of the most widespread electromagnetic radiation in nature, it is based on any object in the regular environment will produce their own molecules and atoms irregular movement, and non-stop radiation of thermal infrared energy, molecules and atoms, the more intense the movement, the greater the energy of radiation, and vice versa, the smaller the energy of radiation.
Temperature in the absolute zero above the object, will be due to their own molecular movement and radiate infrared. Through the infrared detector will be the power of the object radiation signal into an electrical signal, the output signal of the imaging device can be exactly one-to-one correspondence to simulate the spatial distribution of temperature scanning the surface of the object, processed by the electronic system, transmitted to the display, and the object surface heat distribution corresponding to the thermal image. Using this method, it can realize the target for long-distance thermal state image imaging and temperature measurement and analysis and judgment.
