At two selected infrared wavelengths and a certain bandwidth, the ratio of their radiant energy varies with temperature. Has the following performance characteristics:

1. The influence of the emissivity of the measured target on the temperature measurement results can be basically eliminated.

2. The measured target is small and the field of view is incomplete. The presence of soot on the measurement route does not significantly affect the measurement results.

3. The working temperature of the two-color thermometer is mainly in the middle and high temperature area.

4. High precision, fast response and high distance coefficient.

Two sets of different narrow-band monochromatic filters are used to collect radiant energy in two similar wavelength bands and then convert them into electrical signals for comparison. The temperature of the measured object is determined by this ratio.

Therefore, the two-color thermometer can basically eliminate the inconvenience of adjusting the emissivity of the target material, and the temperature measurement sensitivity is higher. The deviation from the real temperature of the target is small, and the influence of the test distance and the absorbent between the two is also small, so the application effect is better in the medium and high temperature range.