Some thermodynamic properties of SF6 on the binodal in the vicinity of the critical point

The presented paper considers a number of problems, with the first of them concerning the analysis of experimental (ρ_l, ρ_g, T)-data of SF₆ at relative temperatures (1.5·10⁻⁸ < τ < 0.3). The second task is to develop combined models (ρ_l (D, C, τ), ρ_g (D, C, τ), …) that agree with a number of boundary conditions, including the requirements of the scale theory of critical phenomena. The third task deals with the calculation of (D, C)-parameters included in the combined models; at this stage, a basic array of (ρ_l, ρ_g, T)-data is formed. It contains: a) experimental results obtained in the laboratory of Prof. Funke (Germany) and b) (ρ_l, ρ_g, T)-data obtained by recalculating some values in the laboratory of Prof. Garrabos (France). The models ρ_l (D, C, τ) and ρ_g (D, C, τ) serve as the basis for computing some thermodynamic functions of SF₆ in the critical region; among them there are complexes, which consist of several properties (the average diameter of a binodal, the order parameter etc.).