Abstract: An apparatus is provided that determines a characteristic of a multiphase fluid, such as an aerated oil and water fluid, flowing within a pipe. The apparatus includes a fluid flow meter, a water cut meter, and a density meter, wherein the density meter determines the density of the fluid flow to determine the gas volume (or void) fraction of the multiphase fluid flow. The output signal of each of the meters is provided to a multiphase flow model to provide a plurality of multiphase parameters, such as phase fraction, volumetric flow, mass flow of each of the phases of the multiphase mixture, optimized for various flow conditions. Each of the meters may be secured to the outer surface of the pipe using various means, such a clamping means.