Basics Of Infrared Thermometry - optris PI 200 Operator's Manual

Basics of Infrared Thermometry

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7 Basics of Infrared Thermometry
Depending on the temperature each object emits a certain amount of infrared radiation. A change in the
temperature of the object is accompanied by a change in the intensity of the radiation.
Searching for new optical material William Herschel by chance found the infrared radiation in 1800.
Figure 43: William Herschel (1738-1822)
He blackened the peak of a sensitive mercury thermometer. This thermometer, a glass prism that led sun
rays onto a table made his measuring arrangement. With this, he tested the heating of different colors of the
spectrum. Slowly moving the peak of the blackened thermometer through the colors of the spectrum, he