noun
humidity meter; hygrometer
Technical term for an instrument that measures humidity, often used in meteorology, agriculture, or indoor climate control.
温室の乾湿計が壊れてしまった。
The humidity meter in the greenhouse broke.
気象観測には乾湿計が欠かせない。
A hygrometer is essential for meteorological observation.
Compound of 乾 (dry), 湿 (wet), and 計 (meter). The exact historical derivation is uncertain, but the spelling is conventionally associated with a device that measures humidity by comparing dry and wet bulb temperatures.