How is the infrared thermometer applied in hot rolling?
1. Basic principles
All objects with temperatures above relative zero are constantly emitting infrared radiation energy into the surrounding space. The infrared radiation characteristics of an object: The size and distribution of radiation energy by wavelength are closely related to its surface temperature. Therefore, by measuring the infrared energy emitted by an object itself, its surface temperature can be accurately measured, which is the objective basis for infrared radiation temperature measurement.
Infrared thermometer, also known as infrared radiation temperature measurement, is a technology that uses the infrared radiation emitted by the object itself to measure the temperature of the object. Infrared radiation, also known as infrared radiation, is a wavelength located at 0.76 μ M~1000 μ The electromagnetic radiation between m, for an ideal blackbody, the total radiation power (referred to as total radiance or radiation intensity) of all wavelengths emitted per unit surface area into hemispherical space is proportional to the 4th power of the object's temperature:
Mb (T)= σ T4 (1)
This is the precise Stephen Boltzmann law. among σ= five point six six nine seven × 10-8W/m2K4 is called the Stephen Boltzmann constant.
(1) The equation is used for actual objects and needs to be multiplied by the emissivity:
Mgb (T)= εσ T4
It can be seen that the spontaneous emission intensity Mgb (T) of any object is related to its temperature and emissivity. The emissivity of an object ε It is directly related to the properties of its material (composition, metal non-metal, crystal amorphous, etc.), surface state (surface smoothness, roughness, oxidation degree, pollution or surface coating, etc.), and the temperature of the object. As long as the radiation rate of the object can be correctly selected, the actual temperature of the measured object can be accurately obtained.
The infrared thermometer is composed of three parts: an optical system, a detection unit, and signal processing. The main function of an optical system is to collect the radiation power of the measured target and converge it onto an infrared detector. The function of an infrared detector is to convert the received infrared radiation into electrical signals for output.
