What is a characteristic of a psychrometer?

A psychrometer is specifically designed to measure humidity in the air. It consists of two thermometers—one that measures the regular air temperature (the dry bulb) and another that has a wet wick and measures the cooling effect of evaporation (the wet bulb). By comparing the readings of these two thermometers, it’s possible to determine the relative humidity of the air.

This measurement is crucial in various applications, including HVAC (heating, ventilation, and air conditioning), because humidity directly affects air comfort and system performance. Understanding the moisture content in the air helps professionals make informed decisions regarding ventilation and climate control. While the other options involve different measurements—like pressure, temperature, and airflow—a psychrometer is unique in its focused capability to assess humidity levels.