hygrometer
/haɪˈɡrɑːmɪtər/
noun
- An instrument used to measure the amount of moisture (humidity) in the air or in a gas.
- We use a hygrometer in the greenhouse to make sure the plants get enough humidity.
- Meteorologists rely on hygrometers to predict rain and fog.
- The digital hygrometer showed that the indoor humidity was too low.