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The velocity of sound with derived state properties in helium at -175 to 150°C with pressure to 150 atm.
J Chem Phys 1976 Mar; 64(6):2556-2568
The velocity of sound was determined in helium on 14 equally spaced isotherms from -175 deg to 150 deg c and at pressures from 10 to 150 atm. The results were correlated with an abbreviated perturbation equation of state which employs both the Lennard-Jones (n,6) and the exponential repulsion potentials. Six parameters in the equation of state were adjusted to fit the velocity data within the experimental precision of about 0.0001%. The derived results reliably predict literature (p, V, t) values and other velocity-of-sound data for pressures as high as 7,000 atm and for temperatures from -223 deg to 577 deg c. A value of the gas constant was derived, r=8,314.79+/- 0.35 Jk-1 lmpl-1, which is statistically consistent with the accepted value. The results also support a recent gas thermometry result that indicates the 1968 temperature scale may be in error by 0.012 K at -183 deg c.
B. E. Gammon, Bartlesville Energy Research Center, Energy Research and Development Administration, Bartlesville, Oklahoma 74003
OP; Journal Article
Issue of Publication
The Journal of Chemical Physics