Abstract: The vibration motor comprises a concentrator of torsional vibrations, whose end face is in close contact with a rotor, and a piezoelectric cell unit adjoining the concentrator of torsional vibrations. Besides, the vibration motor is provided with a magnetic field source arranged under the rotor at the side of the concentrator of torsional vibrations and having a power sufficient to hold the rotor firmly against the concentrator end face, and with magnetic circuit. One part of the latter is movable, being fashioned as a disk with circumferentially spaced slots and rigidly connected to the rotor. The other part of the magnetic circuit separated from the first one by an air gap is stationary. It surrounds the magnetic field source and has peripheral slots identical to those of the movable disk and arranged opposite to them.

Abstract: A method of measuring properties of a fluid in a container, wherein acoustic oscillation pulses are periodically applied to said fluid through the container wall and normally thereto, is disclosed. The acoustic signals are received in the zone of application of the acoustic oscillation pulses as envelopes of the pulse acoustic reverberation produced between the outer surface of the container wall and the fluid, said envelopes being used to form an electrical signal carrying information on the properties of the fluid. A device for measuring properties of a fluid in a container comprises an acoustic transducer positioned directly on the outer surface of the container wall and a series-connected circuit, composed of an electric pulse time delay unit, a gating pulse generator and a gating acoustic signal amplifier, coupled to the acoustic transducer.