Densities of two binary (Helium + Neon) mixtures were measured along six isotherms in the temperature range from (100 to 233.15) K and at pressures of up to 10 MPa, using a low-temperature single-sinker magnetic suspension densimeter. The mixtures were prepared gravimetrically yielding molar Helium fractions of approximately 0.50 and 0.25, respectively. The measurements were carried out at T = (100, 120, 140, 170, 200, and 233.15) K in the homogenous gas region. In total, densities at 72 (T, p) state points were determined. The relative expanded combined uncertainties (k = 2) of the experimental densities were estimated to be within (0.023 and 0.055)%. The largest uncertainty contributions result from the weighing of the sinker and the composition of the prepared mixtures. The experimental results were compared with available experimental literature data as well as with a preliminary mixture model of Lemmon and with a fundamental equation of state of Tkaczuk et al.
Keywords Cryogenic state, density measurement, magnetic suspension coupling, noble gas mixtures, single-sinker densimeter, hydrogen liquefaction