Density Dependence of Experimental Transport Coefficients of Gases

We analyze experimental transport data for several gases as a function of density and temperature. Necessary conditions are proposed to check if the data are consistent with a given density function at fixed temperature. It is found that the theoretically suggested density function, which involves terms logarithmic in the density, satisfies the conditions for the data examined in the temperature and pressure ranges considered. Based on the analyses, first density coefficients of thermal conductivity and viscosity are reported, together with an assessment of their precision, at reduced temperatures up to $\text{T*\hspace{0.17em}≈\hspace{0.17em}30}$ .