**R124**

R124 provides thermodynamic properties for R124 (1-chloro-1,2,2,2-tetrafluoroethane) using the fundamental equation of state described by Reiner Tillner-Roth in ** Fundamental Equations of State,** Shaker, Verlag, Aachan, 1998. Ancillary routines for vapor pressure and saturated liquid and vapor densities are provided by Dr. Steve Penoncello at the Center for Applied Thermodynamic Studies, University of Idaho, Moscow, Idaho. The equation of state is valid for temperatures between 100K and 440 K at pressures lower than 40 MPa.

The values of specific enthalpy and entropy are, by default, referred to 200 kJ/kg and 1.00 kJ/kg-K, respectively for the state of saturated liquid at 273.15 K. The reference state can be changed using the $Reference directive.

__Liquid phase viscosity and conductivity data are from the generalized correlation described by:__

M.J. Assael, N.K. Dalaouti, A.A. Griva, and J.H. Dymond,

"Viscosity and Thermal Conductivity of Halogenated Methane and Ethane Refrigerants",

IJR, Vol. 22, pp. 525-535, 1999.

These property correlations are applicable over the same range as the equation of state.

__Transport properties for the gas phase were fit to data from data obtained from REFPROP 7:__

(E.W. Lemmon, M.O. McLinden, and M. Huber, Physical and Chemical Properties Division, National Institute of Standards and Technology, Boulder, CO 80303, 2002)

__Surface tension data are from: __

Okada, M. and Higashi, Y.,

"Experimental Surface Tensions for HFC-32, CFC-124, HFC-125, HCFC-141b, CFC-142b, and HFC-152a",

*Int. J. of Thermophysics*, Vol. 16, No.3, (1995).