Patent ID: 9599494
Date: 2017-03-21
CPC Classifications: G01F

Claim:
1. Method for operating a magnetic-inductive flowmeter for measuring the flow velocity of a flowing medium, having a magnetic field generator with an electric magnet arrangement and a permanent magnet arrangement for generating a magnetic field with varyingly large magnetic flux densities in the flowing medium, and having a measuring device including a measuring electrode arrangement for measuring the measuring voltage induced by the magnetic field in the flowing medium and superimposed by an interfering voltage, wherein a measuring cycle comprising a compensation measurement sequence and a work measurement event is carried out, wherein at least one first measurement event, at least one second measurement event and at least one third measurement event are carried out during the compensation measurement sequence, wherein a first magnetic flux density is generated in the medium and a first measuring voltage is determined during the first measurement event, wherein a second magnetic flux density is generated in the medium and a second measuring voltage is determined during the second measurement event, wherein a third magnetic flux density is generated in the medium and a third measuring voltage is determined during the third measurement event, wherein the flow velocity is determined using the first magnetic flux density, the second magnetic flux density, the first measuring voltage and the second measuring voltage, wherein the interfering voltage is determined using the third magnetic flux density, the third measuring voltage and the determined flow velocity, wherein the work measurement event is carried out after the compensation measurement sequence and the work measurement event comprising at least one fourth measurement event, wherein the third magnetic flux density is generated in the medium and a fourth measuring voltage is determined during the fourth measurement event, and wherein the flow velocity is determined anew using the third magnetic flux density, the fourth measuring voltage and the determined interfering voltage.