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Eric W. Lemmon


These tables give thermodynamic and transport properties of a variety of fluids, as generated from the equations of state presented in the references below. The properties tabulated are pressure (P), density (ρ), enthalpy (H), entropy (S), isochoric heat capacity (Cv), isobaric heat capacity (Cp), speed of sound (u), viscosity (η), thermal conductivity (λ), and dielectric constant (D). All extensive properties are given on a mass basis. Not all properties are included for every substance. The references should be consulted for information on the uncertainties and the reference states for E, H, and S. Values are first given along the saturation line. The first two points are the properties at the triple point. The final line gives the properties at the critical point. Two lines are given for each temperature (except at the critical point); the first line gives the values of the liquid phase (note the high density) and the second line gives the values of the vapor phase (at low densities). Following the saturation tables, values are given as a function of temperature for several isobars. A duplicate entry in the isobar section indicates a phase transition (liquid-vapor) at that temperature; property values are then given for both phases. The phase can be determined by noting the sharp decrease in density between two successive temperature entries; all lines above this point refer to the liquid phase, and all lines below refer to the gas phase. If there is no sharp discontinuity in density, all data in the table refer to the supercritical region (i.e., the isobar is above the critical pressure). If the first temperature in the isobars is not an integer, this state point refers to the properties of the liquid at the melting line. All temperatures are given on ITS-90 except those for oxygen and helium, where the equations of state still use the IPTS-68 temperature scale. Nitrogen, oxygen, and argon use a reference state based on zero enthalpy in the gas phase at 0 K, parahydrogen, helium, methane, and ethane use a reference state of zero enthalpy and entropy at the saturated liquid state at the normal boiling point, and propane and carbon dioxide use a reference state of 200 kJ/kg and 1 kJ/(kg-K) at –40 °C. Additional calculations at state points not listed below and for fluids not contained here can be obtained for free at the NIST Chemistry WebBook website (, or by using the more comprehensive NIST program REFPROP (
CRC Handbook
Publisher Info


Air, Argon, Carbon Dioxide, Density, Ethane, Heat Capacity, Methane, Nitrogen, Oxygen, Propane, Speed of Sound, Thermal ConductivityViscosity


Lemmon, E. (2009), THERMOPHYSICAL PROPERTIES OF FLUIDS, CRC, CRC, CO (Accessed May 26, 2024)


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Created January 1, 2009, Updated June 2, 2021