The SIKA VVX LowFlow is used for the flow measurement in Heatpumps.
Behind a flowed-around bluff body, counter-rotating and mutually offset vortices arise. The vortices detach at the edges of the bluff body and form a Kármán vortex street in the flow. The distance between the individual vortices is constant. The frequency at which the vortices flow past a sensor depends on the flow velocity and is proportional to the flow rate. The sensor detects the vortices, which are converted into an electrical frequency signal.