Mean velocity and Reynolds‐stress profiles were measured in the incompressible turbulent boundary layer with zero pressure gradient on the aerodynamically smooth sidewall of the German–Dutch windtunnel. Data were taken at Reynolds numbers Re&dgr;2, based on momentum thickness &dgr;2of 2×104, 4×104, and 6×104by means of four different types of hot‐wire probes (three‐wire probes, X wire, and normal‐wire probes). There are also measurements of skin friction and of spectra. The data compare well with the few available other measurements, and all profiles show independence of Reynolds number in the outer region of the boundary layer when plotted againsty/&Dgr;, where &Dgr; is the Rotta–Clauser length. ©1995 American Institute of Physics.