Psychrometer vs. Hygrometer — What's the Difference?

An instrument that uses the difference in readings between two thermometers, one having a wet bulb and the other having a dry bulb, to measure the moisture content or relative humidity of air.

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

(meteorology) Any of several instruments used to measure the relative humidity of the atmosphere; especially a wet-and-dry-bulb hygrometer.

Any of several instruments that measure atmospheric humidity.

An instrument for measuring the tension of the aqueous vapor in the atmosphere, being essentially a wet and dry bulb hygrometer.

(meteorology) An instrument that measures the humidity of the air or other gases, especially the relative humidity.

A hygrometer consisting of a dry-bulb thermometer and a wet-bulb thermometer; their difference indicates the dryness of the surrounding air

An instrument for measuring the degree of moisture of the atmosphere.

Measuring instrument for measuring the relative humidity of the atmosphere