Which of the following instruments is used to measure relative humidity?

A hygrometer is used to measure relative humidity. Relative humidity is the amount of moisture in the air compared to the maximum amount of moisture the air can hold at a given temperature. It is expressed as a percentage. A hygrometer works by measuring the difference between the temperature of the air and the temperature of a substance, such as a wet bulb, that is in contact with the air. The difference between the two temperatures is used to calculate the relative humidity of the air. In simple terms, a hygrometer helps us determine the level of moisture in the air, which can affect comfort and health, as well as preservation of certain items.