Magnetically inductive flowmeter

Magnetically inductive flowmeter (1) for measuring volume flow or flow velocity of a medium flowing through a measuring tube (10), comprising:

• the measuring tube (10) having a measuring tube axis (11) and a measuring tube wall (12);
• a magnet system (20) for producing a magnetic field, which extends perpendicularly to the measuring tube axis, wherein the magnet system is placed on an outside of the measuring tube;
• at least one pair of measuring electrodes (30), which are coupled capacitively or galvanically with the medium located in the measuring tube, wherein the measuring electrodes are adapted to sense an electrical voltage induced in the medium by the magnetic field, wherein a first measuring electrode (31) of the pair of measuring electrodes is arranged on a first side of the measuring tube and a second measuring electrode (32) of the pair of measuring electrodes is arranged on a second side of the measuring tube;
• an electronic measuring/operating circuit (40) for operating the magnet system and the measuring electrodes,
• wherein the magnet system (20) comprises:
• a coil system (21) having at least one coil (21.1) having a coil core (21.2);
• two pole shoes (22), which are arranged on opposite sides of the measuring tube, wherein the pole shoes are adapted to transfer the magnetic field produced by the coil system into the measuring tube as well as to receive the magnetic field, which has passed through the measuring tube, and to lead the magnetic field back to the coil system;
• wherein the coil system (21) has a means for field guide-back (21.3), which is adapted to lead the magnetic field outside of the measuring tube between the pole shoes,
• characterized in that a tangential fraction of the magnetic field in the coil relative to the measuring tube axis amounts to at least 90% of the total magnetic field,
• wherein the means for field guide-back (21.3) has at least one guide-back part (21.4), which extends through at least one coil and forms the coil core (21.2) of the at least one coil (21.1).