Thermometers Dry & Wet

The dry and wet bulb thermometers are essential instruments used together to measure both temperature and relative humidity in the air, commonly employed in meteorology and HVAC applications. The dry bulb thermometer measures the ambient air temperature directly, while the wet bulb thermometer has a cloth wick soaked in water wrapped around its bulb, which cools by evaporation, indicating the lowest temperature achievable by evaporative cooling.

By comparing the temperatures from the dry and wet bulb thermometers, users can calculate relative humidity—the amount of moisture present in the air compared to the maximum it can hold at that temperature. The wet bulb temperature is always equal to or lower than the dry bulb temperature, and the difference between them helps determine air moisture content using psychrometric charts or formulas.

These thermometers typically feature clear, graduated scales for easy reading and precise measurements. The design includes sturdy glass bulbs and protective casing to withstand regular use in laboratory or field environments. The paired use of dry and wet bulb thermometers provides a simple, cost-effective method for assessing air humidity and temperature, vital for understanding weather patterns, climate control, and industrial processes.