Magnetic flowmeter with saturation detection and/or prevention

A method for measuring flow of a process fluid in a pipe, comprising:

• applying a magnetic field to process fluid flowing through the pipe with a magnetic coil;
• sensing an electromotive force (EMF) induced in the pipe due to the applied magnetic field and flow of the process fluid using first and second electrodes;
• measuring the EMF with input circuitry, the measured EMF indicative of flow of the process fluid;
• and
• monitoring the input circuitry, identifying a saturation related condition and responsively providing a diagnostic output.

A magnetic flowmeter for measuring flow of a process fluid in a pipe, the flowmeter comprising:

• a magnetic coil disposed adjacent to the pipe configured to apply a magnetic field to the process fluid;
• first and second electrodes disposed within the pipe which are electrically coupled to the process fluid and configured to sense an electromotive force (EMF) induced in the process fluid due to the applied magnetic field and flow of the process fluid;
• input circuitry electrically coupled to the first and second electrodes having an output related to the sensed EMF;
• and
• saturation prevention circuitry configured to prevent saturation of the input circuitry due to a offset voltage between the first and second electrodes.

A method for measuring flow of a process fluid in a pipe, comprising:

• applying a magnetic field to process fluid flowing through the pipe with a magnetic coil;
• sensing an electromotive force (EMF) induced in the pipe due to the applied magnetic field and flow of the process fluid using first and second electrodes;
• measuring the EMF with input circuitry, the measured EMF indicative of flow of the process fluid;
• and
• preventing saturation of the input circuitry due to an offset voltage between the first and second electrodes.