LAND-M1, 600-1600° C (eyepiece type) pyrometer

Another type is the photoelectric pyrometer, which has the same basic principle as the optical pyrometer. The main difference between them is that photoelectric pyrometers use photoelectric conversion devices instead of human eyes to compare brightness, so the measurement results are not affected by subjective human factors. Some photoelectric pyrometers also use photomultiplier tubes as conversion devices, greatly improving the sensitivity of the instrument and enabling continuous measurement and automatic recording.

Some photoelectric pyrometers also use interference filters instead of red filters, thereby increasing the operating wavelengthλThe precision. The precision photoelectric pyrometer has been used as a reference pyrometer to reproduce temperatures above 1064.43 ℃ in the "1968 International Practical Temperature Scale".

Also known as a ratio pyrometer or dual color pyrometer, it is a pyrometer used to measure the color temperature of an object.

When two definite wavelengths are not blackbodyλ1 andλThe ratio of spectral radiance of 2L(λ1)/L(λ2) When the ratio of the spectral radiance of the same two wavelengths of a blackbody at a certain temperature is equal, the temperature of the blackbody is called the color temperature of the non blackbody.

The measurement range of the colorimetric pyrometer is 800-2000 ℃, and the measurement accuracy can approach ± 1% of the upper range limit. The advantage of a colorimetric pyrometer is that the measured color temperature value is very close to the true temperature. When used in environments with smoke, dust, or water vapor, due to the impact of these media onλ1 andλThe difference in light wave absorption characteristics between 2 is not significant, so the error caused by medium absorption is very small.

For objects (gray bodies) whose spectral emissivity is independent of wavelength, their true temperature can be directly measured. The above advantages are not found in other types of optical pyrometers. The temperature scale of color temperature is determined by brightness temperature, so the measurement accuracy of colorimetric pyrometer is worse than that of photoelectric pyrometer; However, due to its convenient use, colorimetric pyrometers are still widely used in metallurgy and other industries.