What is the primary characteristic measured by a hygrometer?

A hygrometer is an instrument specifically designed to measure humidity, which is the amount of moisture present in the air. Humidity is typically expressed in terms of relative humidity, a percentage that indicates how much moisture is in the air compared to the maximum amount the air can hold at a given temperature.

Understanding humidity is crucial in various applications, including weather forecasting, HVAC systems, and even agriculture, as it affects comfort levels, product preservation, and plant growth. While temperature, pressure, and airflow are important parameters in environmental and building management, a hygrometer focuses solely on quantifying humidity levels, making it an essential tool for maintaining optimal conditions in any space.