Magnetic flowmeter

A method of measuring flow of process fluid using a magnetic flowmeter, comprising:

• receiving the flow of process fluid through a flow tube;
• applying a magnetic field to the flow of process fluid through the flow tube using a first magnetic coil carried by the flow tube;
• sensing a voltage generated in the process fluid which is related to the applied magnetic field and a flow rate of the process fluid through the flow tube;
• determining the flow rate of the process fluid based upon the sensed voltage;
• spreading the magnetic field which emanates from the first magnetic coil and directing a spread magnetic field into the flow tube using a first magnetic field spreader positioned proximate to the magnetic coil;
• and
• completing a magnetic circuit with a tube exterior housing magnetically coupled to the magnetic coil.

A flow tube assembly for use with a magnetic flowmeter for measuring flow rate of a process fluid, comprising:

• a flow tube arranged to receive a flow of the process fluid therethrough;
• a first magnetic coil arranged proximate the flow tube to apply a magnetic field to the process fluid flowing through the flow tube;
• a pair of electrodes electrically coupled to the process fluid in the flow tube and arranged to sense a voltage induced in the process fluid related to the applied magnetic field and a flow rate of the process fluid;
• a first magnetic field spreader positioned proximate the first magnetic coil arranged to spread the magnetic field from the first magnetic coil and direct the magnetic field into the flow tube;
• and
• a tube exterior housing which extends around the flow tube and forms a portion of a magnetic circuit with the first magnetic coil.