Which instrument is often used to measure humidity in underground mines?

The instrument commonly used to measure humidity in underground mines is the psychrometer. This device consists of two thermometers: a dry bulb thermometer, which measures the air temperature, and a wet bulb thermometer, which has a moist wick over its bulb. By comparing the temperatures recorded by the two thermometers, the psychrometer can determine the humidity levels in the air.

In underground mining environments, managing humidity is critical for maintaining worker comfort and safety, as excessive humidity can lead to issues such as heat stress and increased risk of mold and bacterial growth. The psychrometer is particularly useful in these confined spaces where ventilation conditions can significantly affect moisture levels.

While a barometer is used for measuring atmospheric pressure and a hydrometer measures the specific gravity of liquids, these instruments are not suited for accurately monitoring humidity in the air. An anemometer measures air velocity, which is also not related to humidity measurement. Therefore, the psychrometer is the appropriate choice for assessing humidity in the underground mine environment.