There is provided a Karman vortex flowmeter including: a body inside which a flow passage and a Karman vortex generation column are formed; and a flow rate measurement unit that measures Karman vortexes generated by the Karman vortex generation column to thereby obtain a flow rate of a fluid, in which the flow rate measurement unit includes: a piezoelectric element; a piezoelectric element holder that is attached to the body so that the piezoelectric element is arranged in a flow passage; and a thin film part that is formed of a material with higher corrosion resistance than an electrode of the piezoelectric element, the piezoelectric element holder houses the piezoelectric element in a state where the piezoelectric element is sandwiched by a pair of plate-shaped parts integrally formed by a resin material, and in which the thin film part is arranged between the plate-shaped parts and the electrode.

A vortex flowmeter has first and second process connections with a meter inlet and outlet, respectively, therein. The first and second process connections are configured to connect, respectively, to upstream and downstream segments of a fluid pipeline. A fluid conveyance system conveys fluid from the inlet to the outlet and divides the fluid into separate fluid streams that flow through separate passages. Each of the passages has its own vortex metering unit configured to generate and detect vortices in the respective fluid stream. A processing system is configured to calculate a sum of the flow rates through all of the fluid streams.

A capacitive fluid flow sensor and methods for measuring fluid flow are disclosed herein. An exemplary capacitive fluid flow sensor includes an airfoil having a flexible surface, and a capacitive sensor disposed within the airfoil. A capacitance of the capacitive sensor modulates as the flexible surface deflects in response to fluid flow. The fluid flow sensor may be secured within a cooled equipment enclosure, where the flexible surface of the airfoil deflects in response to fluid flow, such as airflow, within the cooled equipment enclosure.

A method for operating a measuring apparatus, comprising the steps as follows: ascertaining a flow velocity comparing the ascertained flow velocity with a threshold value, which corresponds to a critical loading, especially to a resonant frequency, of a measuring apparatus immersion body protruding into the flow; and outputting a report, which signals reaching of a critical flow and/or frequency.

A vortex flowmeter may utilize a ring-shaped bluff body as the vortex generator or shedder. The ring shape and size of the vortex ring generator may be optimized to produce linear and stable toroidal vortex outputs that may outperform the conventional shedder bar. In comparison to the conventional vortex shedder bar, the ring may have a slimmer configuration and a higher K-factor, and hence, a higher resolution.

The sensor comprises: a flat deformation element including first and second planar surfaces; a sensor lug extending starting from the first surface; a connection sleeve extending from the deformation element; a transducer element, which is arranged within the connection sleeve and contacts the first surface with a contact surface, for generating an electrical sensor signal representing temporally changing movements of the sensor lug and/or temporally changing deformations of the deformation element; and a fastener positioned within the connection sleeve and mechanically connected thereto, for fixing the transducer element in the connection sleeve, wherein the fastener includes a spring assembly with at least two stacked disk springs, which are elastically deformed by exerting a pressing force which holds the transducer element against the deformation element.