Thermodynamic Properties of Helium

Temperature K Pressure MPa Density mol/dm3 Volume dm3/mol Int. energy kj/mol Enthalpy kj/mol Entropy kJ/(mol K) c, kJ/(mol K) Q kJ/(mol-K) Sound speed m/s Joule-Thomson K/MPa Therm, cond. mW/(m K) Viscosity TPa s 

The values in these tables were generated from the NIST REFPROP software (Lemmon, E.W., McLinden, M.O., and Huber, M.L., NIST Standard Reference Database 23 Reference Fluid Thermodynamic and Transport Properties—REFPROP, National Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, Md., 2002, Version 7.1). The primary source for the thermodynamic properties is McCarty, R.D., and Arp, V D., A New Wide Range Equation of State for Helium, Adv. Cryo. Eng. 35 1465-1475,1990. The source for viscosity is Arp, V. D., McCarty, R. D., and Friend, D. G., Thermophysical Properties of Helium-4 from 0.8 to 1500 K with Pressures to 2000 MPa, NIST Technical Note 1334, Boulder, Colo., 1998. The source for thermal conductivity is Hands, B. A., and Arp, V D., A Correlation of Thermal Conductivity Data for Helium, Cryogenics, 21(12) 697-703,1981. 

The uncertainties of the equation of state range from 1% at low temperatures ( 20 K) to 0.1% at temperatures between 200 and 400 K, and from 3% in the speed of sound in the liquid phase to 0.1% in the speed of sound between 100 and 500 K. The uncertainty in heat capacities is about 5%. The uncertainty in viscosity is 10%. The uncertainty in thermal conductivity is 5%, except at low temperatures where it increases to 10%. 

Temperature Pressure Density Volume Int. energy Enthalpy Entropy Cp Sound speed Joule-Thomson Therm, cond. Viscosity 

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Table 1. Physical and Thermodynamic Properties of Helium-Group Gas Fluorides, Oxofluorides, and Oxides...

McCarty, R. D., Thermodynamic Properties of Helium, /. Phys. Chem. 

Douglas B. Mann, The Thermodynamic Properties of Helium from 3 to 300°K Between 0.5 and 100 Atmospheres, National Bureau of Standards Technical Note 154, U.S. Government Printing Office, Washington, D.C., 1962,95 pp. 

Lick and Emmons publication on the thermodynamic properties of helium at temperatures up to 50 000 K does not include data for the liquid... 

W. J. Lick and H. W. Emmons, Thermodynamic Properties of Helium to 50,000 K Harvard University Press, Cambridge, Mass., 1962. 

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