Infrared Basic Theory of Industrial Infrared Thermometer
In 1672, it was discovered that 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. Use a dichroic prism to decompose sunlight (white light) into monochromatic lights of red, orange, yellow, green, blue, blue, purple, etc. In 1800, the British physicist F. W. Huxel discovered infrared rays when he studied various colored lights from the thermal point of view. When he was studying the heat of various colors of light, he deliberately blocked the only window of the dark room with a dark plate, and opened a rectangular hole in the plate, and a beam splitter prism was installed in the hole. When sunlight passes through the prism, it is decomposed into colored light bands, and a thermometer is used to measure the heat contained in different colors in the light bands. In order to compare with the ambient temperature, Huxel used several thermometers placed near the colored light band as comparative thermometers to measure the ambient temperature. During the experiment, he accidentally discovered a strange phenomenon: a thermometer placed outside the reddish light had a higher value than other temperatures in the room. After trial and error, this so-called high-temperature zone with the most heat is always located outside the red light at the edge of the light band. So he announced that in addition to visible light, there is also a "hot line" invisible to the human eye in the radiation emitted by the sun. This invisible "hot line" is located outside the red light and is called infrared light. Infrared is a kind of electromagnetic wave, which has the same essence as radio waves and visible light. The discovery of infrared is a leap in human understanding of nature, and it has opened up a new broad road for the research, utilization and development of infrared technology.
The wavelength of infrared rays is between 0.76 and 1000 μm. According to the wavelength range, it can be divided into four categories: near infrared, mid-infrared, far-infrared, and extreme-far infrared. Its position in the continuous spectrum of electromagnetic waves is the area between radio waves and visible light. . Infrared radiation is one of the most widespread electromagnetic radiations in nature. It is based on the fact that any object will produce its own molecular and atomic irregular movements in a conventional environment, and continuously radiate thermal infrared energy, molecular and atomic movements. The more intense, the greater the energy of the radiation, and vice versa, the smaller the energy of the radiation.
Objects with a temperature above absolute zero will radiate due to their own molecular motion
