Abstract: The method for measuring the flow rate of a multi-phase liquid determines the speed of sound and the density of each phase, and determining the speed of sound in each of the phases of the liquid within a working temperature range. The amplitudes of the vibrations of the pipe along which the multi-phase liquid flows and the frequencies corresponding thereto are determined A range of frequencies with maximum amplitude values is selected. The measured range of frequencies is divided into three parts—the low frequencies corresponding to the gas phase, the mid-frequencies corresponding to the oil phase, the high frequencies corresponding to the water phase. In each of the parts of said frequencies the maximum values of the amplitude are isolated after the use of fast Fourier transforms. Then the volumetric flow rate of each phase of the liquid is calculated on the basis of a given formula.

Abstract: The method for measuring the flow rate of a multi-phase liquid determines the speed of sound and the density of each phase, and determining the speed of sound in each of the phases of the liquid within a working temperature range. The amplitudes of the vibrations of the pipe along which the multi-phase liquid flows and the frequencies corresponding thereto are determined A range of frequencies with maximum amplitude values is selected. The measured range of frequencies is divided into three parts—the low frequencies corresponding to the gas phase, the mid-frequencies corresponding to the oil phase, the high frequencies corresponding to the water phase. In each of the parts of said frequencies the maximum values of the amplitude are isolated after the use of fast Fourier transforms. Then the volumetric flow rate of each phase of the liquid is calculated on the basis of a given formula.