| 摘要 |
<p>The disclosed apparatus for sensing the flow of fluid along a passage includes a turbine-type rotor formed of high-resistivity insulation and supported coaxially in the passage. The rotor has spiral vanes distributed about a core. A stator upstream of the rotor provides a spiralling flow pattern in the zone of the rotor. The stator has vanes that spiral in the same direction as the rotor's vanes but as a lower pitch. An electrical sensor provides a varying signal representing the rotation of the rotor. The output signal waves are accurately proportional to the flow over an unusually wide range of flow rates. The electrical sensor includes electrodes exposed to the flow passage, a sensing electrode that is wider than the thickness of a rotor vane and a metal pipe that serves as a companion electrode. Successive pairs of rotor vanes span the sensing electrode at intervals as the rotor turns, periodically acting as barriers that reduce conduction through the fluid in the passage.</p> |
