| 摘要 |
A flowmeter measuring rate of fluid flow comprises a vortex generator of an elongated bluff body disposed generally perpendicular to the flow direction and a vortex detector of an elongated planar member disposed generally parallel to and downstream of the vortex generator on a plane generally parallel to the flow direction, wherein the vortex sensor is fixedly secured to the wall of flow passage at one extremity and coupled to the force receiving member of an impulse detector at the other extremity. The volume flow is determined from the frequencies of vortex shedding and the mass flow is determined from the amplitude of alternating lift forces on the vortex detector exerted by the vortices, which are obtained by processing and analyzing the electric signals from the impulse detector. As an option, the vortex detector may include an electromagnet exerting a testing force of known magnitude in pulses or alternating modes, from which the proportionality relationship between the lift force on the vortex detector and the amplitude of the output from the impulse detector is calibrated on a real time basis.
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