Inductive conductivity sensor

A conductivity sensor for measuring conductivity of a medium surrounding the conductivity sensor, comprising:

• a multi-ply circuit board;
• a first toroidal coil bounding a medium-receiving passageway and serving for inducing an electrical current in the medium;
• and
• a second toroidal coil also bounding the passageway and serving for registering a magnetic field produced by the electrical current, wherein:
• at least one of the toroidal coils has a plurality of first conductor segments, which extend in a plane of said multi-ply circuit board, a plurality of second conductor segments, which extend in a second plane of said circuit board, and a plurality of through contacts, which connect said first conductor segments with said second conductor segments;
• said first conductor segments, said second conductor segments and said through-contacts form, together, the winding of a toroidal coil;
• said first toroidal coil comprises a first ring-core and said second toroidal coil comprises a second ring-core;
• and
• said first ring-core and said second ring-core are arranged coaxially and axially shifted relative to one another.

A conductivity sensor for measuring conductivity of a medium surrounding the conductivity sensor, comprising:

• a multi-ply circuit board;
• a first toroidal coil bounding a medium-receiving passageway and serving for inducing an electrical current in the medium;
• and
• a second toroidal coil also bounding the passageway and serving for registering a magnetic field produced by the electrical current, wherein:
• at least one of said toroidal coils has a plurality of first conductor segments, which extend in a plane of said multi-ply circuit board, a plurality of second conductor segments, which extend in a second plane of said circuit board, and a plurality of through-contacts, which connect said first conductor segments with said second conductor segments;
• said first conductor segments, said second conductor segments and said through-contacts form, together, the windings of a toroidal coil;
• said first toroidal coil comprises a first ring-core and said second toroidal coil comprises a second ring-core, said first toroidal coil and said second toroidal coil are arranged coaxially and coplanarly;
• and
• between said first ring-core and said second ring-core said plurality of through-contacts are arranged.