optris PI LightWeight kit Operator's Manual page 71

Infrared thermometers are optoelectronic sensors. They calculate the surface temperature on the basis of
the emitted infrared radiation from an object. The most important feature of infrared thermometers is that
they enable the user to measure objects contactless. Consequently, these products help to measure the
temperature of inaccessible or moving objects without difficulties.
Figure 17: Main principle of noncontact thermometry
Infrared thermometers basically consist of the following components:

Lens

Spectral filter

Detector

Electronics(amplifier/ linearization/ signal processing)
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