This calculator shows the inter-relationship of air temperature and moisture content with dew point and wet-bulb temperature as measured by a psychrometric thermometer. The Relative Humidity and Mixing Ratio are calculated from the values input.

# Relative Humidity Calculator

Temperature

OR
Atmospheric Pressure

Enter temperature values and atmospheric pressure then press the Compute button to display the output here.

## Explanation about Dry-bulb temperature, Wet-bulb temperature, and Dew point

The temperature and pressure of the air affect how much moisture it can contain. The amount of water vapour that an atmosphere can hold increases with temperature. The Dry-Bulb reading is obtained by using a conventional thermometer to measure the air temperature.

The mixing ratio, or real moisture content, is expressed in grams of water per kilogram of dry air. At a particular temperature, air becomes saturated and cannot hold any more moisture. The proportion of real moisture in the air to fully saturated moisture is known as the relative humidity of the air.

Evaporation can be used to gauge the air's moisture content. When a wet cloth is placed over a thermometer's bulb, and the air is blown over it, the water dries up. The thermometer will cool to a lower temperature than a thermometer with a dry bulb at the same time and location because evaporation absorbs heat.

It is possible to calculate the humidity thanks to the drop in Wet-Bulb temperature. Both the wet and dry bulb temperatures are the same if the air is completely saturated (100 percent relative humidity).

The point at which air becomes saturated is attained if partially saturated air is cooled without affecting its pressure or water vapor content. Dew or ice crystals will be released as a result of the moisture. The Dew Point is at this temperature. Because the air around a bottle of cold beer has been cooled below its dew point, condensation will form on the bottle. In addition to station pressure, meteorological data frequently include the temperature and dew point. These numbers can be used to compute relative humidity and moisture content.

An instrument with a wet and dry bulb thermometer is known as a "psychrometer." This might be a stationary meteorological instrument or a portable sling psychrometer, frequently employed in air conditioning applications.