A formula and tables for the pressure of saturated water vapor in the range 0 to 374 C

Recent experimental determinations of the vapor pressure of water have enriched our knowledge of this property sufficiently to justify revision of the accepted values.A formulation has been developed which by a single equation represents an adjusted composite appraisal of the available data; and defines concisely and explicitly the relation of saturation pressure to temperature between the freezing point and the critical region.Graphical comparisons of the original data with the formula indicate the degree of accord, and the confidence which may be given to the adjusted values.Comprehensive tables of pressures, derivatives, and boiling points, computed by use of the formula are given in several customary units for convenience in compiling complete tables of thermal properties of steam.A table of conversion factors is given. CONTENTSPage I. Introduction 1 II.The formula 2 III.Discussion of the accord of pressure values 3 IV.Discussion of the accord of derivatives 6 V. Steam condensation temperatures for thermometric calibration 8 VI.Tables of saturation pressures, saturation temperatures, and conversion factors 10 I. INTRODUCTIONSeveral determinations of the relation between the temperature and pressure of saturated water vapor have recently been made in the range between the normal boiling point and the critical region.These recent determinations have contributed substantially to the knowl- edge of this property of steam, and have prompted a study of the available data with the object of deducing a single definitive formula that will represent a composite adjusted appraisal and serve for the numerical calculation of explicit values.The advantage of such an interpretation of the vapor pressure data is that it provides a simple and complete method of fixing reliable definitive values of the pressure and its derivative, and furnishes a basis for coordinating other thermodynamic data.