Vorrichtung zur Richtungsanzeige von Luftstroemungen

摘要

An airflow direction indicator has a hollow shaft mounted for sealed rotation into an enclosure and supporting an inner shaft carrying a vane which is located in the airstream. A seal is provided between the inner shaft and the hollow shaft which allows their relative rotation through a limited angle. A servo system is provided which operates to maintain the hollow shaft and the inner shaft within the limited angle relative to one another, and output means indicate the angular position of the hollow shaft relative to a datum position.