Reduced density correlation for hydrogen: Liquid and gaseous states

The available experimental density data for hydrogen have been complied to produce a reduced density correlation for the liquid and gaseous states. This investigation has utilized fifty‐seven sources of data, extending from the early studies of Amagat (1880) to the recent contributions of Johnston, Keller, and Friedman (1954). Based on the concept of a reduced density, a correlation for hydrogen has been developed ranging in temperature from the melting point (14°K.) to 3,300°K. and in pressure as high as 2,550 atm. This correlation provides continuity between the liquid and gaseous phases; whereas existing equations of state fail to describe the experimental behavior in the transitional region, particularly near the critical point. Four hundred and eighty‐five experimental points covering the entire region were checked to establish the reliability of this correlation, which reproduced the experimental data to within 0.49%.