JPS6488217A - Electromagnetic flowmeter - Google Patents

Abstract

PURPOSE:To accurately measure a flow rate by simple constitution without raising cost, by providing a magnetic flux route altering means for bringing the magnetic flux generated between magnetic poles closer to the center of a flow passage. CONSTITUTION:In order to measure the flow rate of the fluid flowing through a flowmeter duct 1, one set of flow rate measuring magnets 30 are arranged at positions not opposed to each other outside of a flow passage and magnetic flux route altering magnets 31 for arranging the shapes of the magnetic fluxes generated by the magnets 30 are provided. Electrodes 5a, 5b and 5c, 5d are arranged outside the circular arc connecting the respective N- and S-poles of the magnets 30, 31 so as to have an angle right-angled to the magnetic flux generated by the segment connecting two electrodes. In order to pass the magnetic fluxes generated by the magnets 30 through the duct 1, said magnetic fluxes are pushed in the duct 1 by the magnets 31 having mutually repulsing magnets poles and the intensities and positions of the magnets 31 are adjusted so as to more push the magnetic fluxes to the central part of the dust in order to perform accurate measurement. By this method, electromotive force is generated in each electrode pair to obtain the output necessary for measurement and the flow rate of a large caliber pipe can be measured by a small-sized lightweight flowmeter.