psychrometric hygrometer
Instrument by which the @[email protected] of the atmosphere may be determined. It is generally composed of two temperature sensors, one of which measures the temperature of the air; the other sensor is moistened with water and senses the cooling due to @[email protected] of water. The temperature difference between the two sensors is a function of @[email protected]; sometimes referred to as a 'wet-and-dry bulb' thermometer.
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2196 [Terms] [Paper]