Electromagnetic flowmeter with multiple poles and electrodes

Electromagnetic flowmeters using Faraday's law have been one of the standard meters to measure liquid flowrate in industry. It has been proved that there are no designs of the exciting magnetic fields that induce the flow signal proportional to volumetric flowrate free from the flow profile. Conversely, it is possible to measure and/or to evaluate flow profiles through the proper design of the magnetic field. This paper describes the theoretical analysis and the experimental results of the flow profile measurement under the rotating magnetic field. Two-dimensional case is treated for the simplicity. In the experiment eight magnetic poles and eight signal pick-up electrodes were used, and a displacement of the pipe position in the x-y plane was compared with concentric position which was occupied by center of poles.