Patent ID: 8640529

Claim:
An apparatus for determining properties of a multiphase fluid comprising a liquid having at least one component and a gas, comprising: a first hollow piezoelectric cylinder having a first axis, an inside wall and an outside wall, wherein the inside wall comprises a first electrode and the outside wall comprises a second electrode; a first signal generator for providing a first chosen electrical signal to one of said first electrode or said second electrode, the other of said first electrode and said second electrode being grounded, whereby said gas is separated from said multiphase fluid flowing through said first hollow piezoelectric cylinder; a second hollow piezoelectric cylinder having a second axis collinear with the axis of said first hollow piezoelectric cylinder, wherein the inside wall of said second cylinder comprises a grounded third electrode, and the outside wall of said second cylinder comprises at least two diametrically opposed fourth electrodes; and a second signal generator for providing a second chosen electrical signal to one of said at least two fourth electrodes, wherein resonant acoustic vibrations are generated in said at least one component; and a gain-phase measurement circuit for comparing the signal from said first signal generator to a signal received by the other of said at least two fourth electrodes, wherein the phase difference between the generated signal and the received signal, and the amplitude of the received signal are determined; whereby the speed of sound in said at least one component and sound attenuation in said at least one component are determined, from which the composition of said at least one component from which the gas has been separated is determined by acoustic interferometry.