Capacitance-type electromagnetic flowmeter.

摘要

Capacitance-type electromagnetic flowmeter capable of measuring flow rates of fluid without being affected by the flow velocity distribution. If the flowtube of the flowmeter is an open conduit, the measurement is made without being affected by variations in the liquid level. The flowmeter comprises the flowtube insulated at least on its inner surface, an exciting means for applying a magnetic field to the fluid perpendicularly to the axis of the flowtube, and a pair of detecting electrodes mounted in the flowtube. The electrodes are electrically insulated from the fluid and extend at right angles to the axis of the flowtube and also to the magnetic field. The length of each electrode taken axially of the flowtube is in proportion to the cosine of an angle made between a normal to the wall of the flowtube and an axis that is perpendicular to both axes of the flowtube and magnetic field. Where the flowmeter comprises a conduit having a free liquid surface, current signals produced from the detecting electrodes are converted by current-to-voltage converter means into voltage signals and taken out.