Appliance for determining and/or monitoring filling level of liquids in container based on oscillating prongs induced to oscillate by piezoelectric membrane

摘要

The appliance has a pair of prongs subjected to controlled oscillation, the change in frequency when in contact with the liquid indicating the filling level. A piezoelectric membrane induces the prongs to oscillate and also monitors the change in frequency. On one side the membrane (15) is quartered to provide electrodes (18,19) for inducing oscillation and electrodes (20,21) for detecting change in frequency. Each pair is diametrically opposed