[en] From Collis' law and the direction sensitivity relation proposed by Hinze it is possible to derive the following relation between the voltage over the wire, the velocity and the angle of incidence of the flow: (V² - V²₀)/R(R-R_a) = b(ρu)^c (sin²ψ + k²cos²ψ)^c/2. T values of the exponent c and the direction sensitivity coefficient k were determined experimentally in the range 20 < ρu < 180 kg/sm². It was found that, if V₀ is the voltage measured with no net flow past the wire, c and k are decreasing with increasing values of ρu. In order to check these calibration experiments, shear stress and turbulence measurements were made in a circular channel. For this geometry the shear stress distribution can be estimated theoretically and several earlier experiments can be used for comparisons. These experiments were made at Reynolds numbers 3 x 10⁵ - 10⁶, Mach numbers 0.1 - 0.3 and a channel length of 61 diameters. Excellent agreement with the theoretical shear stress distribution (corrected for compressibility effects) and earlier data for the axial and radial turbulence components was obtained when the results of the calibration experiments were used for the evaluation of these measurements Evaluation with a constant value of c or with k² equal to zero (as often recommended) gave less good agreement