Vortex flowmeters are used to measure the flow of gases, vapors and liquids in completely filled pipes. The measuring principle is based on the principle of the Karman vortex street. Inside the measuring sensor vortices are shed from a bluff body and are detected by a sensor located behind. The frequency f of the vortex shedding is proportional to the flow velocity v.

The nondimensional Strouhal number S describes the relationshipbetween vortex frequency f, width b of the bluff body andthe mean flow velocity v:

f = (S . v) / b

The vortex frequency is recorded at the sensor and evaluated at the converter.

Functional principle