What is the principle of two-color thermometer?
The monochromatic thermometer is composed of an infrared band sensor and data processing circuit. When measuring the target, the target object is required to fill the field of view, and there must be no smoke or water vapor between the thermometer and the target.
The two-color thermometer is composed of two sensors with different bands and a data processing circuit. The thermometer has certain anti-interference ability against smoke and water vapor.
The two-color thermometer can only measure high-temperature objects, and the two-color thermometer will not be disturbed in a bad environment.
Compared with the single-color thermometer, the two-color thermometer is also a type of infrared thermometer. Its working principle is:
The ratio of radiant energy in two different bands has a certain corresponding relationship with temperature.
Two sets of narrow-bandwidth monochromatic filters are used to receive the radiation energy of two adjacent bands, convert it into electrical signals and compare them. This ratio can be used to determine the temperature of the object being measured.
Compared with single color, the temperature measurement results of dual-color temperature measurement technology are more stable and accurate.
Because it determines temperature through the ratio of radiation energy in two different bands, it reduces the dependence on radiation energy values and is more adaptable to harsh measurement environments than monochromatic thermometers.
For example, when the target is blocked or when measuring smaller targets, the two-color infrared thermometer has more advantages.
When there is a certain obstruction between the field of view and the target, during the process of infrared temperature measurement, the obstruction is mainly reflected in:
1: The measured target or aiming channel is somewhat blocked;
2: There is dust, smoke or water vapor between the infrared thermometer and the measured target;
3: The area passed through during measurement will reduce the radiation energy received by the infrared thermometer, such as grids, fences, small holes, etc.;
4: Increase the observation window when measuring. Because there is moisture or dust on the surface of the window, the infrared transmittance will be changed, thus affecting the measurement results;
5: There is dust or moisture accumulation on the sensor lens.
Generally speaking, when the measured target is blocked or there are obstacles in the temperature measurement field of view, the energy collected by the thermometer will be reduced, but the ratio of radiated energy will not be affected, and the measurement results will still be accurate.
When the target does not fill the field of view of the thermometer, when measuring a smaller target and the target cannot fill the field of view, or when measuring a moving target, the radiation energy will also be reduced;
It has a certain impact on single-color infrared thermometers, but for double-color infrared thermometers, as long as the background temperature is lower than the measured target temperature, accurate measurement results can be obtained.
When the target emissivity is low or changes, when the emissivity of the measured target is unknown, or the target emissivity changes;
As long as the emissivity changes in the two bands are caused by the same factors, then measurements with a two-color thermometer are more accurate than a single-color thermometer.
Whether it is a two-color thermometer or a single-color thermometer, it has the characteristics of high precision, high repeatability, high reliability and fast response;
Online thermometers are widely used for online temperature detection in various industries and harsh environments such as non-ferrous smelting, powder metallurgy, medium and high frequency induction heating, casting, ceramics, welding and heat treatment. It can also be used in other fields such as scientific research and medical treatment. .
