Patent ID: 7102528

Claim:
A device for establishing and/or monitoring a predetermined fill level in a container, comprising: a mechanical oscillatory structure mounted to the container at the height of the predetermined fill level, said mechanical oscillatory structure having a membrane and two mutually separated oscillation bars formed thereon; an electromechanical transducer associate with and adapted to excite said mechanical oscillatory structure to oscillate with oscillations such that said oscillation bars execute oscillations perpendicular to their longitudinal axis; and a receiver and evaluation unit connected to said electromechanical transducer, which uses the oscillations to establish and/or monitor whether the predetermined fill level has been reached, or not, wherein: said oscillation bars are immersed in and moved in a liquid quantity in the container; and said oscillation bars have a shape in which a mass moment of inertia of a liquid quantity is as large as possible and greater than 0.2 times the mass moment of inertia of said oscillation bars.