The invention relates to a method and a device for determining mass flow and/or flow velocity in fluid flows by means of correlation measurement techniques. The aim of the invention is to provide a method for universal application in conjunction with reduced cost and a corresponding device. It is the object of the invention to construct a method and a device in such a way that the determination of mass flow is performed without material marking and independently of the flowing fluid. According to the invention, the object is achieved when discontinuities in the flow which affect the mass are used as physical quantities, and the detection of the fluctuations is performed using mass-sensitive sensors.
