ATTACHABLE GAGE FOR MEASURING LIQUID LEVEL Russian patent published in 2003 - IPC

FIELD: chemical engineering. SUBSTANCE: device has body, piezo-electric element and magnetic ring. The piezo-electric element is inside the device body tightly sealed with cover and has gland inlet for receiving connection cable. The magnetic ring is enclosed into metal box screwed on over gage body. Movable piston from non-magnetic material is mounted inside of the magnetic ring. Piezo-electric element is glued into the recess on the movable piston end face along its lateral surface so that anterior surface of the piezo- electric element is acoustically bound to external reservoir surface and the posterior piezo-electric element surface remains free with damping applied. The piezo-electric element is pressed to wall surface with a spring opened over the piston. Chip having radio elements is fixed on the other piston end face. Two outputs of the chip are connected to the piezo-electric element and the other two are connected to connection cable. The piezo- electric element thickness is selected from the condition that the natural resonance frequency of the piezo-electric element oscillations is to be close to resonance of wall of the reservoir under control on thickness. The piezo-electric element radius is to satisfy to the condition that the wall thickness be within the limits of the nearest zone of the piezo-electric element radiation field. EFFECT: enhanced effectiveness in non-invasively controlling liquid level in reservoir. 3 dwg