Numerical calculation of psychrometric properties on a calculator

Simple and precise equations for calculation of saturation vapour pressure in three di2erent temperature ranges are presented in the paper. Input parameters required for calculation of psychrometric properties are wet- and dry-bulb temperatures, dew point and dry-bulb temperatures and relative humidity and dry-bulb temperature. In this paper, the equations used for computing saturation vapour pressure may also be used for determining dew point temperature for the entire pressure range.