A COMPARISON OF IDEAL AND REAL MOIST AIR MODELS FOR CALCULATING HUMIDITY RATIO AND RELATIVE-HUMIDITY IN THE 213.15 TO 473.15K RANGE AND UP TO A PRESSURE OF 1-MPA

This study evaluates how the ideal mixture model of moist air approxim ates a real mixture model when determining both humidity ratio and rel ative humidity for the 0.1- to 1-MPa pressure range and the -60 to 200 -degrees-C temperature range. The relevant thermodynamic properties ar e calculated using, among others, a specific algorithm based on the re lationships proposed by Hyland and Wexler corrected for the new ITS-90 temperature scale.