Humidity measurement refers to the process of determining the amount of moisture present in the air. This is typically expressed as a percentage, known as relative humidity, which indicates how much water vapor is in the air compared to the maximum amount it can hold at a given temperature. Instruments like hygrometers and psychrometers are commonly used for this purpose. Accurate humidity measurement is important in various fields, including meteorology, agriculture, and HVAC (heating, ventilation, and air conditioning). High humidity can affect comfort levels, while low humidity can lead to dryness and health issues. Understanding humidity helps in making informed decisions in these areas.