Inductive conductivity sensor

• US 7,965,167 B2
• Filed: 01/31/2008
• Issued: 06/21/2011
• Est. Priority Date: 05/29/2006
• Status: Expired due to Fees

• Current Assignee: Endress + Hauser Conducta Gesellschaft Fur Mess- Und Regeltechnik Mbh + Co. Kg
• Original Assignee: Endress+Hauser GmbH+Co (ENDRESS)
• Inventors: Völker, Marco, Eberheim, Andreas, Pechstein, Torsten
• Primary Examiner(s): Mai; Anh T
• Assistant Examiner(s): BAISA, JOSELITO SASIS
• Application Number:
  US12/010,915
• Publication Number:
  US 20080218302A1
• Time in Patent Office: 1,237 Days
• Field of Search: 336/229, 324/445, 324/654
• US Class Current: 336/229
• 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;

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

when said first toroidal coil and said second toroidal coil are surrounded by the medium, said first toroidal coil can be operated as an exciter coil, inducing an electric current in the medium, the current being registered by said second 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 said toroidal coils comprises an air coil.

5. The conductivity sensors claimed in claim 1, wherein:

at least one of said 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 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 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 toroidal coil and said second toroidal coil are arranged coaxially and axially shifted relative to one another.

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

said first and said second toroidal coil are separated from one another by at least a shielding ply for magnetically and capacitively decoupling the coils.

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

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

12. The conductivity sensor as claimed in claim 1,

wherein said first toroidal coil and said second toroidal coil annularly bound said medium-receiving passageway, said passageway comprising a bore in the multi-ply circuit board running essentially perpendicularly to said plane and said second plane of said circuit board.

13. 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.

14. The conductivity sensor as claimed in claim 13, wherein:

said first ring-core and said second ring-core are separated from one another by at least one ply of the multi-ply circuit board; and

a plurality of conductor segments are arranged between said first ring-core and said second ring-core.

15. The conductivity sensor as claimed in claim 13, wherein:

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

16. The conductivity sensor as claimed in claim 13, 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.

17. The conductivity sensor as claimed in claim 13, wherein:

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

18. The conductivity sensor as claimed in claim 13, wherein:

said ring cores comprise one of;

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

19. The conductivity sensor as claimed in claim 13, wherein:

both toroidal coils have 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 together, in each case, form the windings of the respective, two toroidal coils.

20. The conductivity sensor as claimed in claim 19, wherein:

said first and said second toroidal coil are separated from one another by at least a shielding ply for magnetically and capacitively decoupling the coils.

21. The conductivity sensor as claimed in claim 19, further comprising:

electronic circuits on said multi-ply circuit board for operation of the sensor.

22. The conductivity sensor as claimed in claim 13,

wherein said first toroidal coil and said second toroidal coil annularly bound said medium-receiving passageway, said passageway comprising a bore in the multi-ply circuit board running essentially perpendicularly to said plane and said second plane of said circuit board.

23. 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.

24. The conductivity sensor as claimed in claim 23, wherein:

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

25. The conductivity sensor as claimed in claim 23, 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.

26. The conductivity sensor as claimed in claim 23, wherein:

said ring cores are arranged in a cavity in said circuit board between the first and second planes.

27. The conductivity sensor as claimed in claim 23, wherein:

said ring cores comprise one of;

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

28. The conductivity sensor as claimed in claim 23, wherein:

both toroidal coils have 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 together, in each case, form the windings of the respective, two toroidal coils.

29. The conductivity sensor as claimed in claim 28, further comprising:

electronic circuits on said multi-ply board for operation of the sensor.