Patent ID: 8714029

Claim:
A method for determining a flow rate of a fluid through a pipe, wherein first measurement devices are provided which determines a first flow velocity profile of the fluid by means of a Doppler frequency shift, and second measurement devices are provided which determines a second flow velocity profile of the fluid in the pipe by means of a travel time measurement method, comprising the steps of: determining the first flow velocity profile in a first region of said pipe by means of said first measurement devices; determining the second flow velocity profile in a second region of said pipe by means of said second measurement devices; and combining said first and second flow velocity profiles to a total flow velocity profile from which the flow rate of the fluid through the pipe is calculated, wherein the first region of the pipe is a border region and the second region of the pipe is a middle region in a cross section plane of the pipe, wherein at least two first measurement devices are arranged diametrically face-to-face or laterally displaced in a bottom region and an upper region in a cross section plane of said pipe, and wherein the second measurement devices are arranged in said middle region between said bottom and upper region, such that velocity is detectable in several planes.