The Computation of Saturation Vapor Pressure

The physical rationale of the concept of saturation vapor pressure is briefly discussed. Several procedures for the computation of saturation vapor pressure and its derivatives with respect to temperature are examined and evaluated with reference to accuracy relative to currently accepted standards and with reference to computational speed. It is demonstrated that it is possible to devise a set of 6th order polynomial approximations with better than satisfactory accuracy and, further, that these formulas require considerably less computation time than other currently used procedures. Polynomials are derived for various temperature ranges for both ice and water references.