A measurement arrangement comprising a device for determining a flow velocity of a fluid or a fluid component in a pipeline, the device comprising - a transmitter adapted to be placed inside the pipeline and arranged to transmit an ultrasound signal into the fluid or fluid component in a first direction; - a receiver adapted to be placed inside the pipeline and arranged to receive a dispersed ultrasound signal, generated by dispersion of the ultrasound signal by the fluid or the fluid component in a second direction, the second direction being different from the first direction, and to provide a receiver signal representing the dispersed ultrasound signal; and, - a processing unit arranged to receive said receiver signal and to determine a frequency difference between the transmitted ultrasound signal and the dispersed ultrasound signal and determining the flow velocity of the fluid or the fluid component based on said difference, characterized in that: - the fluid comprises a first fluid component and a second fluid component and wherein the processing unit is further arranged to determine a fraction of a volume of the first fluid component with respect to a volume of the fluid; - wherein the processing unit further comprises a discriminator arranged for splitting the receiver signal in a low-level signal and a high-signal based on a predetermined threshold level; and - wherein the processing is arranged to determine said fraction based on said high-level signal; and wherein the processing unit is arranged to determine said frequency difference based on said high-level signal; - wherein the measurement arrangement further comprises a first pipeline segment connected to a second pipeline segment comprising the device, whereby, in use, the first pipeline segment extends in a substantially horizontal direction and the second pipeline segment extends in a substantially vertical direction; and - wherein the first pipeline segment is arranged to receive the fluid or fluid component and provide the fluid or fluid component to the second segment. - a transmitter adapted to be placed inside the pipeline and arranged to transmit an ultrasound signal into the fluid or fluid component in a first direction; - a receiver adapted to be placed inside the pipeline and arranged to receive a dispersed ultrasound signal, generated by dispersion of the ultrasound signal by the fluid or the fluid component in a second direction, the second direction being different from the first direction, and to provide a receiver signal representing the dispersed ultrasound signal; and, - a processing unit arranged to receive said receiver signal and to determine a frequency difference between the transmitted ultrasound signal and the dispersed ultrasound signal and determining the flow velocity of the fluid or the fluid component based on said difference, characterized in that: - the fluid comprises a first fluid component and a second fluid component and wherein the processing unit is further arranged to determine a fraction of a volume of the first fluid component with respect to a volume of the fluid; - wherein the processing unit further comprises a discriminator arranged for splitting the receiver signal in a low-level signal and a high-signal based on a predetermined threshold level; and - wherein the processing is arranged to determine said fraction based on said high-level signal; and wherein the processing unit is arranged to determine said frequency difference based on said high-level signal; - wherein the measurement arrangement further comprises a first pipeline segment connected to a second pipeline segment comprising the device, whereby, in use, the first pipeline segment extends in a substantially horizontal direction and the second pipeline segment extends in a substantially vertical direction; and - wherein the first pipeline segment is arranged to receive the fluid or fluid component and provide the fluid or fluid component to the second segment. - the fluid comprises a first fluid component and a second fluid component and wherein the processing unit is further arranged to determine a fraction of a volume of the first fluid component with respect to a volume of the fluid; - wherein the processing unit further comprises a discriminator arranged for splitting the receiver signal in a low-level signal and a high-signal based on a predetermined threshold level; and - wherein the processing is arranged to determine said fraction based on said high-level signal; and wherein the processing unit is arranged to determine said frequency difference based on said high-level signal; - wherein the measurement arrangement further comprises a first pipeline segment connected to a second pipeline segment comprising the device, whereby, in use, the first pipeline segment extends in a substantially horizontal direction and the second pipeline segment extends in a substantially vertical direction; and - wherein the first pipeline segment is arranged to receive the fluid or fluid component and provide the fluid or fluid component to the second segment.