Apparatus for measuring multiphase fluid flows comprising first and second sections each comprising a flow passage having means for making a dynamic pressure measurement on the multiphase fluid flow therethrough, the geometry of the first and second sections differing so as to affect a relationship between void fraction and velocity for the phases in a known manner. The difference in geometry between the two sections can be in the area of the flow passages or in the direction of flow relation to gravity. A method of measuring multiphase flows comprising the steps of: a) directing the flow through a first flow passage including means for making a dynamic pressure measurement; b) measuring a pressure drop across said means; c) directing the flow through a second flow passage including means for making a dynamic pressure measurement; d) measuring a pressure drop across said means; and e) calculating the composition and flow rates of the phases from the measured pressure drops. The method optionally includes the further steps of directing the flow through a pair of passages and f) intermittently isolating one or other of said pair of passages to prevent flow therethrough; g) measuring at least one property of the fluid as the phases separate in the isolated passage.
