Virial acoustic

The resonant frequencies of an acoustic resonator are determined by the dimension of the cell and by the physical properties of the gas sample determining the sound velocity such as molecular mass, heat capacity, and virial coefficient. 

The acoustic virial coefficient ofQH was determined from the pressure dependence of the sound velocity in the temperature range of 270 K-380 K The second virial coefficient B(T) was calculated from these acoustic virial coefficients and literature values available for B(T) n r 270 K. The resulting temperature dependence and a comparison with data reported by Douslin and Harrison and by Waxman and Davis is shown in Fig. 16. The maximum deviation is 0,8cm /mole at 373 K. 

---