**R23**

Thermodynamic properties for R23 are determined from the fundamental equation of state developed by:

S.G. Penoncello, Z. Shan, and R.T. Jacobsen,

"A Fundamental Equation for the Calculation of the Thermodynamic Properties of Trifluoromethane",

ASHRAE Transactions Paper DA-00-10-1 (RP997), Vol. 106, Pt. 1, 2000

The correlation is valid for temperatures between the triple point (118.02 K) and 475 K for pressures up to 120 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.

**Transport Properties**:

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.

Gas-phase viscosity: 140 K to 475 K

Gas-phase thermal conductivity: 140 K to 475 K

Gas phase viscosity and thermal conductivity and surface tension data were fit to data obtained from the NIST REFPROP 6 program (M.O. McLinden, S.A. Klein, E.W. Lemmon and A.P. Peskin, Physical and Chemical Properties Division, National Institute of Standards and Technology, Boulder, CO 80303, 1995.