Selection and Difference Analysis of Infrared Two-color/Single-color Infrared Thermometer
The two-color thermometer is relative to the single-color thermometer. It is also a kind of infrared thermometer, and it is also the ceiling of the thermometer industry. Its working principle is: the ratio of the radiant energy of two different bands, and the temperature a certain correspondence. 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, which reduces 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 small target, the temperature measurement target cannot fill the field of view, or when measuring a moving target, the radiant energy will also decrease, which has a certain impact on the monochromatic infrared thermometer , but for the two-color infrared thermometer, 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 not known, or the emissivity of the target changes, as long as the emissivity change in the two bands is caused by the same factor, then the measurement with a two-color thermometer is better than a single Color thermometers are more accurate.
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. It is widely used in non-ferrous smelting, powder metallurgy, medium and high frequency induction heating, casting, ceramics, welding and On-line temperature detection in various industries such as heat treatment and harsh environments, and can also be used in other fields such as scientific research.
