Patent ID: 6937943

Claim:
A method for system and process monitoring with an electromagnetic sensor wherein a medium flows through a flow tube essentially in the direction of the flow-tube axis, wherein a magnetic field passes through the flow tube in a direction essentially perpendicular to the flow-tube axis, wherein a measurement voltage is induced in at least one measuring electrode disposed essentially perpendicular to the flow-tube axis, and wherein the induced measurement voltage or the measurement data provide information about the volume flow of the medium in the flow tube, the method comprising the steps of: determining over a predetermined period of time the measurement data, digitizing and storing same as actual measurement data; comparing the actual measurement data with predetermined, desired data; and outputting a message when a deviation is detected between the actual measurement data and the desired data wherein: the frequency spectrum (U(f)) of the voltage values induced in the measuring electrode is used for the system and/or process monitoring.