What is the principle of the two-color thermometer?
The monochromatic thermometer is composed of an infrared band sensor and a data processing circuit. When measuring the target, the target must fill the field of view, and there should be no smoke, water vapor, etc. 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 a 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 when the environment is not good.
The two-color thermometer is relative to the single-color thermometer. It is also a kind of infrared thermometer. Its working principle is:
The ratio of the radiation energy of two different bands has a certain correspondence with the temperature.
Two sets of narrow-bandwidth monochromatic filters are used to receive the radiant energy of two adjacent bands, convert them into electrical signals and compare them, and use this ratio to determine the temperature of the measured object.
Compared with single-color temperature measurement technology, the temperature measurement result of the two-color temperature measurement technology is more stable and accurate.
Because it determines the temperature through the ratio of the radiant energy of two different bands, thus reducing the dependence on the radiant energy value, it is more adaptable to the harsh measurement environment than the monochromatic thermometer.
For example, when the target is blocked, or when measuring a small target, the two-color infrared thermometer is more advantageous.
When there is a certain occlusion between the field of view and the target, in the process of infrared temperature measurement, the occlusion is mainly reflected in:
1: The measured target or the aiming channel is blocked;
2: There is dust, smoke or water vapor between the infrared thermometer and the measured target;
3: The area passed by the infrared thermometer during measurement will reduce the reception of radiant energy 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 result;
5: Dust or moisture has accumulated on the sensor lens.
Generally speaking, when the measured target is blocked or there is an obstacle in the temperature measurement field of view, the energy collected by the thermometer will decrease, but the ratio of radiant 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, the target cannot fill the field of view, or when measuring a moving target, the radiant energy will also decrease;
It has a certain influence on single-color infrared thermometers, but for two-color infrared thermometers, as long as the background temperature is lower than the temperature of the measured target, accurate measurement results can be obtained.
When the emissivity of the target is low or changes, when the emissivity of the target to be measured is unknown, or the emissivity of the target changes;
As long as the change in emissivity in both bands is caused by the same factors, measurements with a two-color pyrometer are more accurate than a single-color pyrometer.
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;
The online thermometer is widely used in non-ferrous smelting, powder metallurgy, medium and high frequency induction heating, casting, ceramics, welding and heat treatment and other industries and online temperature detection in harsh environments. It can also be used in scientific research, medical treatment and other fields. .
