What is black body radiation?
What exists in the world is reasonable, and what exists has its meaning and value. Rarely discovered what infrared light can do? We can use infrared as a remote control, and remote sensing technology uses the characteristics of long infrared wavelengths, and of course, we want to talk about temperature measurement. So how does an infrared thermometer use infrared to measure temperature? First, let's look at black body radiation. Do you mean black objects? A black body is actually an idealized object that can absorb all external electromagnetic radiation without any reflection or transmission. Any object, as long as it is warmer than absolute zero, is radiating electromagnetic waves. Electromagnetic waves are oscillating particle waves generated and emitted in space by electric and magnetic fields that are in the same phase and perpendicular to each other, and are electromagnetic fields that propagate in the form of waves. A black body looks black below 700K, but that's only because the radiant energy emitted by a blackbody below 700K is very small and the radiation wavelength is outside the visible range. If the temperature of the black body is higher than the above temperature, the black body will no longer be black, it will start to turn red, and as the temperature increases, orange, yellow, white and other colors will appear. Taking steel as an example, according to the process of temperature increase, it turns red, orange, and yellow respectively. When the temperature exceeds 1300 degrees Celsius, it starts to turn white and blue. When a black body turns white, it also emits a lot of ultraviolet light.
