Magnetic flowmeter with ultrasonically cleaned electrodes

In a magnetic flowmeter comprising a body adapted to be connected in a flow system for measuring the flow of a fluid therethrough, means for generating a magnetic field in the fluid flowing through the body, a pair of electrodes in said body for producing a voltage dependent on the electric field generated in the fluid flowing through the magnetic field, signal processing means for converting the output voltage to an output signal, ultrasonic transducers associated with the electrodes for cleaning the faces of the electrodes when activated, and ultrasonic generator means for periodically activating the transducers, the improvement comprising sequencing means for placing at least a part of said signal processing means in a hold state during activation of said transducers so as to hold said output signal at an instantaneous level, thereby eliminating interference with said output signal by said ultrasonic generator.