A new fundamental equation of state expressed as a function of the Helmholtz energy is presented for 3,3,3-trifluoroprop-1-ene (R-1243zf). The equation is valid from the triple-point temperature (122.35 K) to 430 K at pressures up to 35 MPa. The expected uncertainties ( \(k = 2\) ) in calculated properties from the equation of state are 0.1 % for vapor pressures, 0.1 % for liquid densities, 1 % for vapor densities, 0.3 % for saturated liquid densities, 1 % for saturated vapor densities, 0.06 % for vapor-phase sound speeds, and 2 % for liquid-phase isobaric heat capacities. Differences between experimental and calculated vapor pressures are within 2 kPa in most cases. Uncertainties for caloric properties are particularly improved from the former equations of state. Various plots of constant-property lines demonstrate that not only does the equation exhibit correct behavior over all temperatures and pressures within the range of validity, but also that it shows reasonable extrapolation behavior at extremely low and high temperatures, and at high pressures.
