Properties of Pure Fluids - NIST Pure Fluids
Appendix A: FLUIDS IN THE NIST PURE FLUIDS DATABASE
| Ammonia | Neon |
| Argon | Nitrogen |
| Butane | Nitrogen trifluoride |
| Carbon dioxide | Oxygen |
| Carbon monoxide | Parahydrogen |
| Deuterium | Pentane |
| Ethane | Propane |
| Ethylene | R-123 (2,2-dichloro-1,1,1-trifluoroethane) |
| Fluorine | R-124 (1-chloro-1,2,2,2-tetrafluoroethane) |
| Helium | R-125 (pentafluoroethane) |
| Heptane | R-134a (1,1,1,2-tetrafluoroethane) |
| Hexane | R-143a (1,1,1-trifluoroethane) |
| Hydrogen (normal) | R-152a , (1,1-difluoroethane) |
| Isobutane | R-22 (chlorodifluoromethane) |
| Krypton | R-32 (difluoromethane) |
| Methane | Xenon |
The bolded fluids are considered primary standards with typical uncertainties of 0.02% in density, 0.5% in heat capacities and the liquid speed of sound, and 0.02% in the vapor speed of sound. The italicized fluids are also high accuracy equations with typical uncertainties in density of 0.1%, 0.5% in heat capacities and the liquid speed of sound, and 0.1% in the vapor speed of sound. The uncertainties of all of the equations can be found in the information screen described in Section 4.2.1.