Patent ID: 11441931

Abstract:
The disclosure relates to a magnetoinductive flowmeter. In order to detect gas bubbles in a measuring tube, and thus an incompletely filled measuring tube, the control signal with which the magnetic field generating device is actuated is designed as an alternating rectangular pulse with time delays. A first pulse time delay is provided after a positive rectangular pulse and a second pulse time delay is provided after a negative rectangular pulse during one period, wherein no magnetic fields are provided during the pulse time delays. The measurement signal is evaluated during the duration of the rectangular pulses (MB+, MB−) in order to ascertain the flow speed of the medium and during the duration of the time delays (Mess1 , Mess2) in order to monitor the functionality, wherein the impedence between the two measurement electrodes is ascertained via the noise level of the measurement signal during the time delays (Mess1 , Mess2), and the noise level of the measurement signal during the time delays (Mess1 , Mess2) is a measurement of a malfunction, the impedance between the two measurement electrodes being influenced by air bubbles or foreign particles in the measurement medium.