Which instrument obtains air temperature by measuring emitted infrared energy?
A) radiometer
B) bimetallic thermometer
C) electrical resistance thermometer
D) thermograph

Question

Quizplus · Accepted Answer

A radiometer measures the radiant energy in the infrared portion of the electromagnetic spectrum emitted by an object, which is directly related to its temperature. Therefore, it can obtain air temperature by measuring emitted infrared energy. The other options are not capable of measuring temperature in this way - a bimetallic thermometer measures temperature by the expansion and contraction of metals due to temperature changes, an electrical resistance thermometer measures temperature by the variation of its electrical resistance with temperature, and a thermograph measures temperature by marking the temperature change on a chart over time.

Which Instrument Obtains Air Temperature by Measuring Emitted Infrared Energy