What is a Hygrometer?

• A. A humidity analyzer that measures the physical and electrical changes that occurs in materials as they release and absorb moisture
• B. A humidity sensor used for weather
• C. Hygrometer
• D. A moisture meter

Answer: (C)

A hygrometer is the instrument used to measure humidity in the air, typically reporting relative humidity. It encompasses different sensing methods, from hair-based expansions to capacitive or resistive sensors, all aimed at quantifying how much water vapor is in the surrounding air.

This is the best fit because the word describes the device itself—an instrument dedicated to humidity measurement. The other descriptions refer to devices or concepts related to moisture but not the standard instrument for ambient humidity: measuring moisture content in materials (moisture meters) or describing a sensor used for weather without naming the instrument.