Psychrometer Constant

Psychrometer constant is used in the study of evapotranspiration and thermodynamics, particularly in meteorology and agriculture.  It relates the rate of evaporation from a wet surface to atmospheric conditions such as air temperature and humidity.  The psychrometer constant helps in understanding how quickly water evaporates under given environmental conditions.  It is used for modeling water balance in ecosystems, agricultural planning, and irrigation scheduling.

Key Concepts about Psychrometer Constant

Psychrometer  -  A device used to measure humidity. It consists of two thermometers one with a dry bulb and the other with a wet bulb.  The difference in temperatures between these two thermometers can help determine humidity.
Evapotranspiration  -  The process by which water is transferred from land to the atmosphere by evaporation from soil and transpiration from plants.

 

Psychrometer Constant Formula
\( \lambda \;=\;  Q \;  p_a  \;/\; \lambda \; M \)
Symbol	English	Metric
\( \gamma \)   (Greek symbol gamma) = Psychrometer Constant	-	\(kPk\;/\;C\)
\( Q \) = Specific Heat Capacity of air	-	\(kJ\;/\;kg-K\)
\( p_a \) = Atmospheric Pressure	-	\(kPk\)
\( \lambda \) = Latent Heat of Vaporization of Water	-	\(kJ\;/\;kg\)
\( M \) = Ration of Molecular Weight of Water Vapor to Dry Air	-	\(dimensionless\)