| 摘要 |
<p>The flowmeter delivers an output signal depending on the flow. It consists of a vane wheel in a housing chamber, operated tangentially by the flow. The vane wheel drives a movable element of an electric signal generator. The medium whose flow is to be measured operates the vane wheel (4) by a jet from a narrow nozzle (5). The housing chamber is surrounded by a coil (7), part of an oscillator (9) oscillating circuit. It generates in the chamber (6) an alternating magnetic field perpendicular to a plane passing through the vane wheel (4) axis. The movable element of the signal generator is a small metal plate or a short-circuiting winding (10) on the vane wheel (4). When the wheel rotates, this movable element is at times perpendicular and at times parallel to the coil (7) magnetic field. When the plate etc. is perpendicular to the magnetic field, oscillating circuit is so strongly damped, that oscillations periodically stop. They restart when the plate etc. nears its parallel position.</p> |
