Reference data on the viscosity of rarefied steam at a temperature of $2000$ to $2500$ K

An extensive array of experimental data on the coefficients of viscosity and self-diffusion of rarefied steam at temperatures ranging from $280$ to $1773$ K is fitted using relations of molecular kinetic theory and the generalized four-parameter Stockmayer potential. The parameters are found, namely, the collision diameter $d=2.495\mathring{A}$, the depth of potential well $\varepsilon=689.7$ K, the exponent of the repulsion branch $m=9$, the dipole moment $\mu=1.803$ D, and their error matrix. The tables of reference data are calculated up to $2500$ K. The estimates are suggested of their confidence errors, as well as the upper limit of the model validity with respect to temperature.