Density Equation for Saturated 3He

A density equation for saturated vapor and liquid 3He is preseInted based on 205 experimental measurements for temperatures greater than 0.2K collected after a careful survey of the literature. The average deviation of the densities predicted by the equation against the experimental values is 0.39%. There are only 16 points with deviations larger than 1%. This equation is valid for both liquid and vapor densities of 3He up to the critical temperature of 3.3157 K. The form of the equation satisfies known scaling laws approaching the critical point, with β =0.3653. In the low-density limit, the vapor curve of our equation matches smoothly to the published virial equation density at a temperature of 1.62K and at the saturation pressure. The rectilinear density deviates from the critical density by less than 0.28% down to 0.48 K.