Abstract: A method of controlling gas-liquid or liquid-liquid interface in monolayer reservoirs, wherein mechanical vibrations are excited within a section of the reservoir wall by means of a wave of acoustic vibrations, the velocity of propagation of mechanical vibrations being approximately equal to that of the wave wake of acoustic vibrations along this wall, the interface being ascertained from the amplitude of the acoustic wave transformed from said mechanical vibrations which propagate along said reservoir wall. A device for performing said method consists of two sound conductors with effective areas, an emitter of the wave of acoustic vibrations and a receiver of an acoustic wave being established on said effective areas respectively.

Abstract: Disclosure is made of a method for checking the thickness of sheet materials, whereby acoustic oscillation is sent in the form of a traveling wave through a material being checked roughly perpendicularly to its surface. The amplitude of the acoustic oscillations that have passed through the material being checked is measured and compared to that of a reference signal, whereby the thickness of the sheet material is determined. The proposed device for checking the thickness of sheet materials comprises an acoustical radiator and an acoustical receiver. The working surface of the radiator and receiver are roughly parallel to the surface of a material being checked, which material is placed between the radiator and receiver. The distance between the radiator and receiver is selected to be in excess of the spatial extension of the traveling wave during each measurement period.

Abstract: A method of controlling physical characteristics of a fluid medium by transmitting ultrasonic vibrations to the medium under control through a sound conducting medium and through a pipe wall at an angle .alpha., acute or obtuse, to the pipe exterior, said angle being determined by the relationship:.alpha. = arcsin C.sub.o /(.sqroot.2.multidot.C)where:C.sub.o is the velocity of propagation of ultrasonic vibrations in the sound conducting medium; andC is the velocity of propagation of transverse ultrasonic vibrations in the material of the pipe wall.Therewith, the frequency f of the ultrasonic vibrations being transmitted is selected according to the relationship:f = (n .multidot. C)/(.sqroot.2 .multidot. d)where:n is an integer (such as 1, 2 or 3); andd is the thickness of the pipe wall.Parameters of the ultrasonic vibrations, passed through the medium under control, are then measured and their value is used to determine the value of a parameter being controlled.

Abstract: An apparatus and method for controlling liquid pressure in pipelines wherein the apparatus comprises an ultrasonic measuring converter including an ultrasonic emitter and an ultrasonic receiver mounted on the outer surface of the pipeline; a measuring unit incorporated in the apparatus having a driving pulse generator connected to the emitter and connected via a time delay unit to a reference pulse shaper; the output of the reference pulse shaper is connected to one input of an information pulse shaper which has its other input connected, via a signal pulse shaper and an amplifier to the ultrasonic receiver; the output of the information pulse shaper is connected to an input of an information pulse control unit and to an input of a control pulse shaper which has an output connected to the other input of the information pulse control unit; an output of the information pulse control unit is connected to an information pulse converter which is connected to a recording instrument.