Critical parameters for propane determined by the image analysis

The (p, ρ, T) measurements and visual observations of the meniscus for propane were carried out carefully in the critical region over the range of temperatures: −60 mK ⩽ (T − Tc) ⩽  40 mK and of densities: −4 kg · m−3 ⩽ (ρ − ρc) ⩽ 6 kg · m−3 by a metal-bellows volumometer with an optical cell. Vapour pressures were also measured at T = (320.000, 343.132, 369.000, and 369.625) K. The critical point of Tc, ρc, and pc was determined by the image analysis of the critical opalescence. Comparisons of the critical parameters with values given in the literature are presented.