Humidity sensors

Besides temperature, humidity, i.e., the water vapor content of the air, is a meteorologically important factor. This becomes clear when one considers that water in its various forms is involved in a large number of meteorological phenomena. This applies not only to clouds, fog, and the many types of precipitation, in whose formation and evaporation enormous amounts of energy are transferred, but also to the emission and absorption of long-wave radiation, for which the water vapor content of the air is essential.