The instrument used to measure relative humidity is called

The instrument used to measure relative humidity is called a hygrometer.
A hygrometer is a device that helps us determine the amount of moisture or water vapor present in the air. It measures the relative humidity, which is the percentage of moisture in the air compared to the maximum amount of moisture the air can hold at a given temperature.
There are different types of hygrometers, but one common type is the "dry and wet bulb" hygrometer. It consists of two thermometers: one thermometer with a dry bulb and another with a wet bulb.
To measure relative humidity, the wet bulb thermometer is wrapped with a moistened cloth. As the moisture on the cloth evaporates, it causes the wet bulb temperature to decrease. The dry bulb thermometer remains unaffected.
By comparing the temperatures of the dry and wet bulbs, we can calculate the relative humidity using a formula. The difference between the two temperatures helps us understand how much moisture is in the air.
So, in summary, a hygrometer is used to measure relative humidity by comparing the temperatures of a dry bulb and a wet bulb thermometer. It helps us understand how much water vapor is present in the air.