Key words: saturation line, density, sulfur hexafluoride, order parameter, rectilinear diameter
Information on the behavior of the SF6 density on the binodal in the asymptotic vicinity of the critical point 3·10-6 < τ < 2 · 10 -4, where τ = (Tc - T)/Tc , — relative temperature is presented. The densities of the liquid (ρl) and vapor (ρg) phases were calculated based on the experimental data of Garrabos et al. (2018) about the height h at which the meniscus is located separating the two phases of the sample in a horizontal cell with a diameter d at a temperature T under conditions of Earth gravity. As the second component of the method, the order parameter fs(τ) is considered in analytical form, which corresponds to the scale theory (ST) of critical phenomena and is based on (ρl, ρg,T -data from Funke et al. (1998) for SF6 in the range 10-3 < τ <0,3. Several problems are formulated, including the construction of dependencies ρl(τ) и ρg(τ), corresponding to ST and correlating with (h,T)-data for 10-6 < τ < 10-3. The relationship between (h,T) data and the functions fs(τ) и fd(τ) (where fd is the average or rectilinear diameter) is investigated. The dependences of ρl(τ) and ρg(τ) on temperature in the range 10-6 < τ < 10-3 were calculated. The dependences ρl(τ) and ρg(τ) that correspond to ST and working satisfactorily in the range 10-6< τ < 10-3 were constructed.
doi:10.34984/SCFTP.2023.19.1.002