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Measuring the temperature of air using a radiation thermometer.

Written by Riho Kato | Jun 30, 2023 8:41:59 AM

 

 

Can air temperature be measured with an infrared thermometer?

In conclusion, it is not possible to measure air temperature with an infrared thermometer.

If air temperature could be measured with an infrared thermometer,

it would result in measuring the temperature of the air regardless of the object being measured.

Therefore, infrared thermometers are equipped with infrared sensors that are sensitive to the wavelength range of

8-14 μm, where there is minimal emission of infrared energy from the air.

 

Gases present in the atmosphere strongly absorb specific wavelengths of infrared radiation that pass through the atmosphere.

In certain wavelength ranges, they are affected by the thermal radiation emitted by the air,

making it difficult to accurately measure the temperature of the target object.

As shown in the figure above, the wavelength range of 8-14 μm is known as the "atmospheric window."

This range has high transparency in the atmosphere, with low absorption of infrared radiation by the air.

In other words, there is minimal infrared radiation energy emitted by the air in this wavelength range.

Therefore, conventional infrared thermometers utilize infrared sensors sensitive to the 8-14 μm range to

minimize the influence of thermal radiation from the air.

 

In essence, infrared thermometers are designed to exclude the measurement of air temperature in order to

accurately measure the temperature of the target object.