A torsional vortex sensor comprises an extended member disposed across a flow passage extending through a flowmeter body and experiencing a fluctuating fluid dynamic force associated with vortex shedding occurring in a stream of fluid moving through the flow passage wherein the extended member is supported by the flowmeter body in a relationship allowing at least a minute amount of pivotal movement of the extended member about a pivot axis perpendicular to the center line of the flow passage and offset from the geometrical center line of the extended member defined by a line connecting the geometrical center of every cross section of the extended member taken parallel to a plane including the center line of the flow passage, and at least one lateral extension member disposed exteriorly to the flow passage and extending from the extended member wherein the lateral extension member is connected to two force transmitting members respectively extending from two piezo electric transducers disposed respectively on two opposite sides of a plane including the pivot axis; wherein the two piezo electric transducers respectively generate two electrical signals which are combined into an alternating electrical signal representing the vortex shedding.
