US Patent 7942070 Flow rate sensor

The invention relates to a flow sensor having a measuring chamber to which a fluid whose volume and/or rate of flow is to be measured is supplied and then drawn off. Inside the measuring chamber elements of a measuring mechanism are mounted so as to freely rotate. The sensor is also provided with a magnet which produces a magnetic field inside the measuring chamber and in close proximity thereto. At least one sensor device measures the magnetic field and/or changes in the magnetic field. The sensor device for measuring the magnetic field is provided with at least one giant magnetoresistance sensor.