Patent ID: 7191638

Claim:
A device for determining and/or monitoring at least one physical parameter of a medium having: at least one mechanically oscillatable unit; and at least one drive/receive unit, wherein: said drive/receive unit excites said mechanically oscillatable unit to oscillate, or said drive/receive unit receives the oscillations of said oscillatable unit; said drive/receive unit is provided with at least one piezo-drive, which has at least one exterior surface, said at least one pieze-drive which is composed of at least two segments having different polarizations with the directions of polarization being directed essentially opposite to one another; said mechanically oscillatable unit is directly or indirectly connected with said exterior surface, so that said mechanically oscillatable unit is excited to a movement, or so that a movement of said mechanically oscillatable unit is received, with the movement in each case being composed of at least two different force components, and the force components are ones of push and pull, and the movement is a wagging movement or rotary movement in a plane which is perpendicular to said at least one exterior surface of said piezo-drive.