NIST logo
Dr. Eric W. Lemmon


Dr. Lemmon received his Ph.D. at the University of Idaho in 1996.  The dissertation introduced a new Helmholtz energy model for mixtures of hydrocarbons, cryogens, and refrigerants based on a generalized excess Helmholtz energy concept.  His current work focuses on the Refprop program ( and on national and international standards for the properties of natural gas.  

Google Scholar Citation Page

Research Interests:

He is the chair of the ISO committee that will publish the next standard for the equation of state for these mixtures.  Dr. Lemmon has developed many equations of state and a new nonlinear fitting technique that allows operations that are not available in linear methods.  This has resulted in much smaller equations that extrapolate without limits in all directions.

Representative Publications: 

Lemmon, E.W., Jacobsen, R.T, Penoncello, S.G., and Friend, D.G., "Thermodynamic Properties of Air and Mixtures of Nitrogen, Argon, and Oxygen from 60 to 2000 K at Pressures to 2000 MPa," J. Phys. Chem. Ref. Data, 29(3):331-385, 2000.

Lemmon, E.W. and Goodwin, A.R.H., "Critical Properties and Vapor Pressure Equation for Alkanes CnH2n+2: Normal Alkanes with n <= 36 and Isomers for n = 4 Through n = 9," J. Phys. Chem. Ref. Data, 29(1):1-39, 2000.

Lemmon, E.W. and Jacobsen, R.T, "Equations of State for Mixtures of R-32, R-125, R-134a, R-143a, and R-152a," J. Phys. Chem. Ref. Data, 33(2):593-620, 2004.

Lemmon, E.W. and Jacobsen, R.T, "Viscosity and Thermal Conductivity Equations for Nitrogen, Oxygen, Argon, and Air," Int. J. Thermophys., 25(1):21-69, 2004.

Lemmon, E.W. and Jacobsen, R.T, "A New Functional Form and New Fitting Techniques for Equations of State with Application to Pentafluoroethane (HFC-125)," J. Phys. Chem. Ref. Data, 34(1):69-108, 2005.

Lemmon, E.W. and Span, R., "Short Fundamental Equations of State for 20 Industrial Fluids," J. Chem. Eng. Data, 51:785-850, 2006.

Lemmon, E.W., McLinden, M.O., and Wagner, W., "Thermodynamic Properties of Propane.  III.  A Reference Equation of State for Temperatures from the Melting Line to 650 K and Pressures up to 1000 MPa," J. Chem. Eng. Data, 54:3141-3180, 2009.

Dr. Eric W. Lemmon


University of Idaho: Ph.D., Mechanical Engineering


Theory and Modeling of Fluids
Thermophysical Properties Division
Boulder, CO 80305-3337

phone: 303-497-7939
fax: 303-497-5044