Multi-property evaluation for a gas sample based on the acoustic and electromagnetic resonances measurement in a cylindrical cavity

Abstract This study proposes a multi-property evaluation method for a gas sample on the basis of sound speed and relative permittivity measurements by using a cylindrical acoustic-electromagnetic resonator. Validity and reliability of the present apparatus were confirmed from the measurement result for Ar with the relative standard uncertainties of 2×10–4 for the sound speed and 4×10–6 for the relative permittivity. The sound speed and the relative permittivity measurements for trans-1-chloro-3,3,3-trifluoropropene, which is known as R1233zd(E), were carried out in the wide temperature and pressure ranges to demonstrate the multi-property evaluation for a polar molecular sample. Firstly, specific heat capacity and molar polarization in the ideal-gas state were derived from the sound speed and the relative permittivity data, respectively, based on the acoustic- and the dielectric-virial equations. Secondly, linear regression of the ideal-gas molar polarization and temperature data leaded information of dipole moment and molecular polarizability in accordance with Debye equation. The density-virial coefficients were deduced by use of an empirical correlation with the determined dipole moment on the basis of the corresponding states principle so that the acoustic- and the dielectric-virial coefficients were separately determined from polynomial regression analysis of the sound speed and the relative permittivity data, respectively. Finally, the relative permittivity data in combination with the determined dielectric-virial coefficients yield the value of density. The acquired multi-property data for R1233zd(E) were compared with the existing equation of state or reference model.