bolometer

n. instrument to measure radiant energy

A bolometer is a device for measuring the energy of incident electromagnetic radiation. It was invented in 1878 by the American astronomer Samuel Pierpont Langley.It consists of an "absorber" connected to a heat sink (area of constant temperature) through an insulating link. The result is that any radiation absorbed by the absorber raises its temperature above that of the heat sink—the higher the energy absorbed, the higher the temperature will be. A thermometer of some kind, attached to the absorber, is used to measure the temperature, from which the absorbed energy can be calculated. In some designs the thermometer is also the absorber; in others the absorber and thermometer are separate; this is known as "composite design".
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Noun
1. an instrument that measures heat radiation; extremely sensitive
(hypernym) measuring instrument, measuring system, measuring device

n. bolometer, instrument to measure radiant energy

n. bolometer, instrument to measure radiant energy