Oscillation compensating apparatus for vortex flow meter.

摘要

In a vortex flow meter for measuring a varying flow rate of a fluid through a conduit, an oscillation compensating apparatus (10) is constructed to remove undesirable externally derived oscillation noise which is applied to the flow meter. An elongate vortex shedding member (12) extends into the conduit (14) through part of its wall. The shedding member (12) forms a shedding portion inside the conduit (14) and a compensating portion outside the conduit. The shedding portion carries a first oscillation sensor (22) therewith and the compensating portion, a second oscillation sensor (24). The first sensor (22) is sensitive to an oscillation component caused in the shedding portion by a vortex train shed in the conduit, and an externally derived oscillation noise component. The second sensor (24) is sensitive to the noise component only. All these sensed components are combined to cancel the oscillation noise so that only the oscillation component in the shedding portion is picked up.