摘要 |
<p>360-77-0070 DRAG FLOW METER A drag-type flow meter is disclosed of the type having a drag plate disposed in the fluid flow stream, the velocity of which is to be measured, The drag plate is mounted on a cantilevered arm which is pivotally mounted externally of the fluid flow passage, with a tensioned wire counteracting the drag force tending to pivot the arm. The tensioned wire is disposed in a magnetic field and an electrical current is passed through the wire to cause vibration of the wire, the frequency of which varies linearly with the drag force exerted on the drag plate due to the corresponding change in wire tension. Varying frequency of the current provides a digital electrical signal which varies linearly with fluid flow velocity. Embodiments are described enclosing the wire mounting components in a vacuum housing in order to minimize the air damping of the wire vibration, and a mounting arrangement minimizing the effects of temperature variation on the output signal,</p> |