Abstract
Biplane wind vanes with four interplane angles and a box wind. vane of the German Fuess type are tested in the wind tunnel concerning the time constant of their damped oscillation in the tunnel current. The observation is carried out in four steps of wind speed up to 20 m/s. The time constants are investigated with respect to the interplane angle and compared with that of the Fuess type which is rather inferior to the biplane type, contrary to the declaration given by the manufacturer.
