Liquid—Vapor Equilibrium in the System Equilibrium Hydrogen—Helium

Liquid—vapor equilibrium-phase compositions for the binary system 20.40° equilibrium hydrogen—helium have been determined for six isotherms in the range 20.40°—31.50°K and at pressures up to 500 psia. The vapor recirculation method of obtaining equilibrium was used in conjunction with a liquid-hydrogen vapor-pressure-controlled cryostat. Analyses were made on a mass spectrograph. The results are presented in both tabular and graphical form, and comparisons with those reported previously for the system normal hydrogen—helium have also been made.