The instrument used to measure relative humidity is called

A.

hygrometer

B.

anemometer

C.

thermometer

D.

barometer

Correct answer is A

A hygrometer is an instrument used to measure the amount of humidity and water vapor in the atmosphere, in soil, or in confined spaces. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass, a mechanical or electrical change in a substance as moisture is absorbed.