Which one of the following instruments is used for measuring moisture content of air ?

A hygrometer is the scientific instrument specifically designed to measure the moisture content or humidity of the air [3]. It functions by recording evaporation rates, tension adjustments, or environmental changes to track water vapor levels. One common type is the psychrometer, which utilizes wet-bulb and dry-bulb thermometers to determine relative humidity [1]. In contrast, a hydrometer is used to measure the specific gravity or density of liquids. A hypsometer is an instrument used to determine altitude by measuring the boiling point of liquids, and a pycnometer is used for measuring the density of solids or liquids. Measuring humidity is critical in meteorology, industrial food processing, and museum preservation to maintain specific environmental conditions [2].

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 13: Weather > Notes > p. 120
2. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 24: Hydrological Cycle (Water Cycle) > Water Vapour In Atmosphere > p. 325
3. [2] Exploring Society:India and Beyond ,Social Science-Class VII . NCERT(Revised ed 2025) > Chapter 2: Understanding the Weather > THINK ABOUT IT > p. 38