Which of the following instruments measures infra-red radiation?

Options

A. Phenograph
B. Pyrheliometer
C. Cathetometer
D. Bolometer

Answer

D

Explanation

Bolometer-It is a device to measure infra-red radiation. pyrheliometer-A pyrheliometer is an instrument designed specifically to measure the direct beam solar irradiance. Cathetometer-It is a device used for accurate measurement of small vertical distances.