[en] The transport coefficients (the drift velocity and the lateral diffusion coefficient to mobility ratio) have been measured in mixtures of 0.5% and 4% hydrogen in argon. All measurements were made at 293K. It is shown that for these mixtures the use of the solution of the Boltzmann equation based on the two-term Legendre expansion of the velocity distribution function introduces no significant error in the analysis of the transport data. All the experimental data have been predicted to within +-3.5% using previously published cross section data