Inductive conductivity sensor

• US 20080218302A1
• Filed: 01/31/2008
• Published: 09/11/2008
• Est. Priority Date: 05/29/2006
• Status: Active Grant

• Current Assignee: Endress + Hauser Conducta Gesellschaft Fur Mess- Und Regeltechnik Mbh + Co. Kg
• Original Assignee: Endress + Hauser Conducta Gesellschaft Fur Mess- Und Regeltechnik Mbh + Co. Kg
• Inventors: Eberheim, Andreas, Pechstein, Torsten, Volker, Marco
• Granted Patent: US 7,965,167 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: G01N 27/025 a current being generated within the material by induction

Abstract

A conductivity sensor for measuring conductivity of a medium surrounding the conductivity sensor includes 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. At least one of the toroidal coils has a plurality of first conductor segments, which extend in a plane of a multi-ply circuit board, a plurality of second conductor segments, which extend in a second plane of the circuit board, and a plurality of through-contacts, which connect the first conductor segments with the second conductor segments, wherein the first conductor segments, the second conductor segments and the through-contacts form, together, the windings of a toroidal coil.

Claims

1. 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; and

said first conductor segments, said second conductor segments and said through-contacts form, together, the windings of a toroidal coil.

2. The conductivity sensor as claimed in claim 1, wherein:

said through-contacts extend essentially perpendicularly to the plies of said circuit board.

3. The conductivity sensor as claimed in claim 1, wherein:

said first and said second, conductor segments are, in each case, embodied as conductive traces on an outer surface of said circuit board or on an intermediate ply in said circuit board.

4. The conductivity sensor as claimed in claim 1, wherein:

at least one of the toroidal coils comprises an air coil.

5. The conductivity sensor as claimed in claim 1, wherein:

at least one of the toroidal coils comprises a ring-core coil.

6. The conductivity sensor as claimed in claim 5, wherein:

said ring-core is arranged in a cavity in said circuit board between the first and second planes.

7. The conductivity sensor as claimed in claim 5, wherein:

said ring-core comprises one of;

a solid ring-core, a wound-tape ring-core and a plastic ring-core with magnetic particles.

8. The conductivity sensor as claimed in claim 1, wherein;

both toroidal coils have a plurality of first conductor segments, which extend in a plane of said multi-ply conductor 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 together, in each case, form the windings of the respective, two toroidal coils.

9. The conductivity sensor as claimed in claim 1, wherein:

said first and said second toroidal coils are arranged coaxially and axially shifted relative to one another.

10. The conductivity sensor as claimed in claim 1, wherein:

said first and said second toroidal coils are arranged coaxially and coplanarly.