A practical density equation for saturated vapor of helium-3 from 0.01 K to the critical point

摘要

Based on the ideal gas state equation and the saturated vapor pressure equation of helium-3, a saturated vapor density equation is proposed, which can be applied for calculating the saturated vapor density of helium-3 from 0.01 K to the critical temperature. Above 1.4 K, the average deviation between the results by this equation and experimental data is about 0.66 percent and the maximum is 2 percent. Below 1.4 K, the results of this work show a comfortable agreement with those by virial state equation (the deviations are generally within 0.1 percent). Based on this new vapor density equation, the compressibility factor of saturated vapor is determined and the vaporization heat is calculated.