Description

A whirling psychrometer is a device used to measure the relative humidity of the air. It consists of two thermometers: a dry-bulb thermometer and a wet-bulb thermometer. The dry-bulb thermometer measures the ambient air temperature, while the wet-bulb thermometer measures the temperature of a wetted wick as air passes over it. Here's how a whirling psychrometer works: Wet the wick of the wet-bulb thermometer with distilled water. Attach the dry-bulb and wet-bulb thermometers side by side on a handle or a frame. Rapidly spin the psychrometer in the air for a few minutes. This spinning motion helps evaporate water from the wetted wick, causing the wet-bulb temperature to drop. After spinning, observe and record the temperature readings from both thermometers. The difference between the dry-bulb and wet-bulb temperatures is used to calculate the relative humidity of the air using a psychrometric chart or equation. The evaporation of water from the wet-bulb thermometer causes the temperature to decrease, and the rate of evaporation is influenced by the humidity of the surrounding air. The lower the relative humidity, the greater the evaporation and the greater the temperature difference between the dry-bulb and wet-bulb thermometers. By using the psychrometric chart or equation, the temperature readings from the whirling psychrometer can be used to determine the relative humidity, dew point temperature, and other properties of the air. This information is valuable in various applications, such as weather forecasting, HVAC systems, and industrial processes where humidity control is important.