Dwyer Instruments, Inc.

Robert W Butts

Steven O Buchanan

Air velocity gauge

An air velocity gauge for direct measurement of low air flow or draft rates in the range of 20-400 feet per minute comprising a generally flat housing of quadrilateral shape defining a draft way therethrough and a set of opposed draft way inlet and outlet openings that are aligned with the plane of the housing that approximate the size and general shape of the way. A vane formed from a strip of Mylar polyester film is suspended pendulum fashion from the upper portion of the housing adjacent the draft way inlet and is creased longitudinally of same to rigidify the vane to act as such rather than as a flexible flap. The housing itself is in the form of an open centered center frame with open sides, to each side of which is applied a transparent side plate held in place by an adhesively backed opaque scale or scale plate that adheres to lands defined by the housing center frame for this purpose. The scale plates are formed with mirror image windows struck on the arc of movement of the vane that are calibrated to directly read air flow velocity in proportion to the vane deflection about its pivot axis. The housing end plates are formed with cooperating ports for housing a level bubble vial for leveling the gauge; the housing side plates are also formed to define fastener receiving sleeves for mounting the gauge in use.

Growing community of inventors

Lakeville, IN, United States of America

Robert W Butts