The 2 color pyrometer has high sensitivity and fast response, can observe small targets, and has high halo measurement accuracy. The temperature measured by the colorimetric pyrometer is closer to the real temperature than the optical pyrometer and the total radiation pyrometer. It can be used to measure the temperature of molten iron, molten steel and slag.

The colorimetric temperature can be less than, equal to or greater than the true temperature. _eAi=~2, that is, when the measured object is a gray body, the colorimetric temperature is equal to the real temperature of the measured object, which is the biggest advantage of the colorimetric pyrometer. For example: the surface of heavily oxidized steel can generally be regarded as a gray body. At this time, the indication value of the instrument is the colorimetric temperature, which can be considered to be approximately equal to the real temperature of the measured object without correction.
While the e-values and ~-values vary widely for real objects, the ratio values for the same object vary little. Therefore, the difference between the colorimetric temperature and the real temperature is much smaller than the difference between the brightness temperature, the radiation temperature and the real temperature, and the measurement accuracy is high.
Water vapor, carbon dioxide and dust in the optical path all absorb the monochromatic radiation energy under the wavelength and A2. Although the absorption is similar, it has little influence on the ratio of monochromatic radiation power (brightness ratio), so the colorimetric pyrometer can Use in harsh environments.