Magnetic-inductive flowrate measuring method with periodic switching of magnetic field polarity when difference between sampled flowrate values exceeds threshold value

摘要

The measuring method uses a pair of measuring electrodes spaced perpendicular to the axis of a measuring pipe for the flow medium and a magnetic axis applied perpendicular to both the measuring pipe axis and the line between the measuring electrodes, with detection of the voltage at one or both measuring electrodes relative to a reference potential, for determination of the flowrate. The latter is measured at a defined sampling rate for a constant magnetic field, the sampled flowrate values compared with one another for periodic switching of the magnetic field polarity when a given difference threshold is exceeded.