Wet & Dry Bulb Hygrometer

Wet & Dry Bulb Hygrometer

Catalogue No. – 19083
mounted on plastic base, range -10 to
50 [table “19083” not found /]


A lab wet & dry bulb hygrometer, also known as a psychrometer, is a type of instrument used to measure relative humidity in the air. It consists of two thermometers mounted side by side, one with a wet wick and the other dry. The wet wick thermometer has a cotton wick that is soaked in distilled water and exposed to the air. The dry bulb thermometer measures the temperature of the surrounding air.

To use the instrument, the wet wick is first moistened and then both thermometers are whirled in the air for a few minutes until the readings stabilize. The difference in temperature readings between the wet and dry bulb thermometers, called the wet bulb depression, is used to calculate the relative humidity of the air using a psychrometric chart or formula.

Wet & dry bulb hygrometers are widely used in laboratories, as well as in meteorology, HVAC systems, and industrial applications to measure and control humidity levels.