MAGNETIC FLOWMETER

A magnetic flowmeter comprises a flow tube assembly, an electromotive force EMF sensor, a power amplifier, a current sampling circuit and a controller. The flow tube assembly accommodates the fluid flow and includes a coil for receiving a coil current and initiating an EMF proportional to the flow rate in the fluid flow. The EMF sensor generates an output indicative of the initiated EMF. The poweramplifier is used for generating an unfiltered current pulse of a first frequency. The power amplifier includes a low pass filter that attenuates the unfiltered current pulse to form a coil current pulse of a second frequency, the coil current pulse forming a coil current. The current sampling circuit samples the coil current pulse at a sampling frequency. The controller is configured to change arelationship between the sampling frequency and a first frequency and adjust the coil current based on the sample.