What is "psychrometrics"

n. (context meteorology English) The study of the physical and thermodynamic properties of the atmosphere and its water vapour.

Psychrometrics or psychrometry or hygrometry are terms used to describe the field of engineering concerned with the determination of physical and thermodynamic properties of gas-vapor mixtures. The term derives from the Greek psuchron (ψυχρόν) meaning "cold" and metron (μέτρον) meaning "means of measurement".