Electrochemical electrode assembly

• US 4,466,878 A
• Filed: 01/12/1983
• Issued: 08/21/1984
• Est. Priority Date: 01/12/1983
• Status: Expired due to Fees

• Current Assignee: Il Holding SpA (Werfen SA)
• Original Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Inventors: Maciel, Robert F., Harris, John C., DiNitto, Robert G.
• Primary Examiner(s): Andrews, R. L.
• Assistant Examiner(s): Chapman, Terryence
• Application Number:
  US06/457,509
• Time in Patent Office: 587 Days
• Field of Search: 204/297 R, 204/415, 204/416, 204/417, 204/418, 204/419, 204/420, 204/1 P, 204/286, 128/635
• US Class Current: 204/415
• CPC Class Codes: G01N 27/404 Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid , e.g. Clark-type oxygen sensors

Abstract

A replaceable cartridge assembly for use with electrochemical analysis apparatus includes a housing of electrically insulating material that defines an annular electrolyte chamber with coupling structure at one end of the housing and a chamber port at the other end of the housing. A selectively permeable membrane extends across the port in sealing relation thereto. An elongated guide channel within the housing is surrounded by the electrolyte chamber and receives a cooperating connector stem that carries a socket-temperature sensor assembly. A cathode electrode projects coaxially upwardly from the end wall of the guide channel into the stem socket and the lower portion of the cathode electrode extends through the guide channel end wall such that its tip is exposed to the membrane. An anode electrode is disposed in the electrolyte chamber with an external contact surface adjacent the coupling structure. Electrolyte in the annular chamber extends through the chamber port into the region between the membrane and the tip of the cathode electrode to provide an electrically conductive path between the anode and cathode electrodes.

Claims

1. A replaceable cartridge assembly for use with electrochemical analysis apparatus comprising

housing structure of electrically insulating material that defines an annular electrolyte chamber, coupling structure at one end of said housing structure, an electrolyte chamber port at the other end of said housing structure,

a selectively permeable membrane extending across said port in sealing relation thereto,

an elongated cavity within said housing structure that has an open port adjacent said coupling structure through which the projecting stem of a cooperating connector component is adapted to be inserted, said cavity being bounded by an end wall remote from said coupling structure and by side wall structure of electrically insulating material extending between said port and said end wall that defines the inner wall of said annular electrolyte chamber,

a cathode electrode extending through said cavity end wall with a cathode electrode contact surface exposed at the base of said cavity for engagement with an electrical contact member carried at the end of said projecting stem, said cathode electrode having a tip at its end opposite said cathode electrode contact surface in juxtaposed relation to said membrane,

an anode electrode extending through a wall of said housing with an anode electrode contact surface exposed adjacent said coupling structure and a major portion of said anode electrode disposed in said electrolyte chamber, and

electrolyte in said annular chamber such that said electrolyte is disposed annularly around said cathode electrode and extends through said port into the region between said membrane and the tip of said cathode electrode to provide an electrically conductive path between said anode and cathode electrodes.

2. The assembly of claim 1 wherein said housing structure includes a tubular housing of electrically insulating material that defines a through passage, said coupling structure being at one end of said tubular housing and said electrolyte chamber port being at the other end of said tubular housing, and an insert subassembly that is secured in said tubular housing, said subassembly including flange structure at one end for coupling to said tubular housing through passage and a stem portion of electrically insulating material extending axially from said flange structure, said stem portion defining said elongated cavity and said electrolyte chamber being defined between said stem portion and said tubular housing.

3. the assembly of claim 2 wherein said flange structure has a planar surface and said anode electrode is a metal wire and an end of said anode electrode wire projects above said planar surface of said flange structure and defines said anode contact surface.

4. The assembly of claim 3 wherein said cathode and anode electrodes are silver wires.

5. The assembly of claim 2 wherein said coupling structure is of the screw-type and said flange structure of said insert subassembly is coupled to said tubular housing by means of said screw-type coupling structure.

6. The assembly of claim 1 wherein said elongated cavity is of cylindrical configuration and has a length to diameter ratio of at least four, said coupling structure is of the screw type, said housing includes an annular surface that is recessed below said screw type coupling structure, said planar surface defining said cavity port and extending radially thereabout, said anode electrode has a portion that projects through and above said annular surface that defines said anode contact surface, and said cathode electrode has a portion that extends coaxially upwardly from the end wall of said cylindrical cavity and defines said cathode electrode contact surface.

7. A replaceable cartridge assembly for use with electrochemical analysis apparatus comprising

housing structure of electrically insulating material that defines an annular electrolyte chamber, coupling structure at one end of said housing structure, an electrolyte chamber port at the other end of said housing structure,

a selectively permeable membrane extending across said port in sealing relation thereto,

an elongated cavity within said housing structure that has an open port adjacent said coupling structure through which the projecting stem of a cooperating connector component is adapted to be inserted, said cavity being bounded by an end wall remote from said coupling structure and by side wall structure extending between said port and said end wall that defines the inner wall of said annular electrolyte chamber,

a cathode electrode extending through said cavity end wall with a cathode electrode contact surface exposed at the base of said cavity for engagement with an electrical contact member carried at the end of said projecting stem, said cathode electrode contact structure being in the form of a coaxially projecting length of said cathode electrode that extends upwardly from said cavity end wall and said cathode electrode having a tip at its end opposite said cathode electrode contact surface in juxtaposed relation to said membrane,

an anode electrode extending through a wall of said housing with an anode electrode contact surface exposed adjacent said coupling structure and a major portion of said anode electrode disposed in said electrolyte chamber, and

electrolyte in said annular chamber such that said electrolyte is disposed annularly around said cathode electrode and extends through said port into the region between said membrane and the tip of said cathode electrode to provide an electrically conductive path between said anode and cathode electrodes.

8. A connector assembly for use with a replaceable cartridge unit in an electrochemical electrode apparatus, said cartridge unit including coupling structure, structure defining an electrolyte chamber, a port at one end of said electrolyte chamber, a selectively permeable membrane extending across said port in sealing relation thereto, structure defining a recess within said cartridge unit, a cathode electrode supported in said recess with the tip of said cathode electrode in juxtaposed relation to said membrane and a cathode electrode contact surface in said recess, an anode electrode with an anode electrode contact surface exposed adjacent said coupling structure and a major portion of said anode electrode disposed in said electrolyte chamber, and electrolyte in said chamber such that said electrolyte extends through said port into the region between said membrane and the tip of said cathode electrode to provide an electrically conductive path between said anode and cathode electrodes;

said connector assembly including a fixed projecting stem of electrically insulating material,

a first electrical contact member at the end of said stem for electrically engaging said cathode electrode contact surface,

an electrical conductor extending through said stem from said first contact member,

a temperature sensor in said stem in intimate thermal association with said first contact member,

a second electrical contact member at the end of said stem remote from said first contact member for electrically engaging said anode electrode contact surface,

coupling structure for engagement with said coupling structure of said cartridge unit to interconnect said cartridge unit and said connector assembly with said second contact member in electrical engagement with said anode contact and said first contact member in electrical engagement with said cathode contact; and

means for electrically connecting said contact members to a remote location to conduct the electrical signal provided by said electrodes to said remote location.

9. The assembly of claim 8 wherein first electrical contact member and said temperature sensor are embedded in thermally conductive material at the end of said stem.

10. The assembly of claim 8 wherein said projecting stem is of cylindrical configuration and has a length to diameter ratio of at least four, said first electrical contact member is of the resilient socket type with an opening coaxially disposed at the end of said stem, said second electrical contact member is an annular contact that surrounds said stem at the end of said stem adjacent said coupling structure, and said coupling structure is of the screw type.

11. The assembly of claim 8 wherein thermal insulation is provided in said projecting stem between said temperature sensor and said coupling structure.

12. The assembly of claim 11 wherein said thermal insulation is a sealed air gap region.

13. The assembly of claim 12 wherein said first electrical contact member is of the resilient socket type, said temperature sensor has a first lead extending through said stem and a second lead electrically connected to said conductor;

and said second electrical contact member is an annular contact that surrounds said stem at the end remote from said socket.

14. An electrochemical electrode assembly comprising

a detachable cartridge component and a cooperating connector component,

said cartridge component comprising housing structure of electrically insulating material that defines an annular electrolyte chamber, coupling structure at one end of said housing, an electrolyte chamber port at the other end of said housing,

a selectively permeable membrane extending across said port in sealing relation thereto,

an elongated cylindrical cavity within said housing bounded by an end wall remote from said coupling structure and by wall structure of electrically insulating material that defines the inner wall of said annular electrolyte chamber,

a cathode electrode extending through said cavity end wall with the tip of said coaxially projecting length of said cathode electrode in juxtaposed relation to said membrane and a coaxially projecting length of said cathode electrode in said elongated cavity,

an anode electrode extending through a wall of said housing with an anode electrode contact surface exposed adjacent said coupling structure and a portion of said anode electrode disposed in said electrolyte chamber, and

electrolyte in said annular chamber such that said electrolyte is disposed annularly around said cathode electrode and extends through said port into the region between said membrane and the tip of said cathode electrode to provide an electrically conductive path between said anode and cathode electrodes;

said connector component including a fixed projecting cylindrical stem of electrically insulating material,

a first electrical contact member at the end of said stem for electrically engaging said coaxially projecting length of said cathode electrode,

an electrical conductor extending through said stem from said contact structure,

a temperature sensor in said stem in intimate thermal association with said first contact member,

a second electrical contact member at the end of said stem remote from said first contact member for electrically engaging said anode electrode contact surface, and

coupling structure for engagement with said coupling structure of said cartridge component to interconnect said cartridge component and said connector component with said stem disposed in said elongated cavity so that an annular air gap is provided therebetween, said second contact member is in electrical engagement with said anode contact and said first contact member is in electrical engagement with said cathode contact; and

means for electrically connecting said electrode assembly to a remote location to conduct the electrical signal provided by said electrode assembly to said remote location.

15. An electrochemical electrode assembly comprising

a detachable cartridge component and a cooperating connector component,

said cartridge component comprising housing structure of electrically insulating material that defines an annular electrolyte chamber, coupling structure at one end of said housing, an electrolyte chamber port at the other end of said housing,

a selectively permeable membrane extending across said port in sealing relation thereto,

an elongated cavity within said housing bounded by an end wall remote from said coupling structure and by wall structure that defines the inner wall of said annular electrolyte chamber,

a cathode electrode wire extending through said cavity end wall with the tip of said cathode electrode wire in juxtaposed relation to said membrane and a coaxially projecting length of said cathode wire extending upwardly from said cavity end wall to provide a cathode electrode contact surface in said elongated cavity,

an anode electrode extending through a wall of said housing with an anode electrode contact surface exposed adjacent said coupling structure and a portion of said anode electrode disposed in said electrolyte chamber, and

electrolyte in said annular chamber such that said electrolyte is disposed annularly around said cathode electrode and extends through said port into the region between said membrane and the tip of said cathode electrode wire to provide an electrically conductive path between said anode an cathode electrodes;

said connector component incuding a projecting stem,

a first electrical contact member at the end of said stem for electrically engaging said cathode electrode contact surface, an electrical conductor extending through said stem from said first contact member,

a temperature sensor in said stem in intimate thermal association with said first contact member,

a second electrical contact member at the end of said stem remote from said first contact member for electrically engaging said anode electrode contact surface, and

coupling structure for engagement with said coupling structure of said cartridge component to interconnect said cartridge component and said connector component with said stem disposed in said elongated cavity so that an annular air gap is provided therebetween, said second contact member is in electrical engagement with said anode contact and said first contact member is in electrical engagement with said cathode contact; and

means for electrically connecting said electrode assembly to a remote location to conduct the electrical signal provided by said electrode assembly to said remote location.

16. An electrochemical electrode assembly comprising

a detachable cartridge component and a cooperating connector component,

said cartridge component comprising housing structure of electrically insulating material that defines an annular electrolyte chamber, coupling structure at one end of said housing, an electrolyte chamber port at the other end of said housing,

a selectively permeable membrane extending across said port in sealing relation thereto,

an elongated cylindrical cavity within said housing bounded by an end wall remote from said coupling structure and by wall structure that defines the inner wall of said annular electrolyte chamber, said cavity having a length to diameter ratio of at least four,

a cathode electrode extending through said cavity end wall with the tip of said cathode electrode in juxtaposed relation to said membrane and a cathode electrode contact surface in said elongated cavity,

an anode electrode extending through a wall of said housing with an anode electrode contact surface exposed adjacent said coupling structure and a portion of said anode electrode disposed in said electrolyte chamber, and

electrolyte in said annular chamber such that said electrolyte is disposed annularly around said cathode electrode and extends through said port into the region between said membrane and the tip of said cathode electrode to provide an electrically conductive path between said anode and cathode electrodes;

said connector component including a projecting cylindrical stem, said stem having a length to diameter ratio of at least four,

a first electrical contact member at the end of said stem for electrically engaging said cathode electrode contact surface, an electrical conductor extending through said stem from said first contact member,

a temperature sensor in said stem in intimate thermal association with said first contact member,

a second electrical contact member at the end of said stem remote from said first contact member for electrically engaging said anode electrode contact surface, and

coupling structure for engagement with said coupling structure of said cartridge component to interconnect said cartridge component and said connector component with said stem disposed in said elongated cavity so that an annular air gap is provided therebetween, said second contact member is in electrical engagement with said anode contact and said first contact member is in electrical engagement with said cathode contact; and

means for electrically connecting said electrode assembly to a remote location to conduct the electrical signal provided by said electrode assembly to said remote location.

17. The assembly of claim 16 wherein first electrical contact member is of the resilient socket type, said temperature sensor has a first lead extending through said stem and a second lead electrically connected to said conductor;

and said second electrical contact member is an annular contact that surrounds said stem at the end remote from said socket.

18. The assembly of claim 17 wherein said housing structure incudes a tubular housing of electrically insulating material that defines a through passage, said coupling structure being at one end of said tubular housing and said electrolyte chamber port being at the other end of said tubular housing, and an insert subassembly secured in said tubular housing, said subassembly including flange structure at one end sealingly attached to said tubular housing through passage and a tubular stem portion of electrically insulating material extending axially from said flange structure, said tubular stem portion defining said elongated cavity and said electrolyte chamber being defined between said stem portion and said tubular housing.

19. The assembly of claim 18 wherein said cathode electrode is a metal wire and said cathode electrode contact surface is a coaxially projecting length of said cathode wire that extends upwardly from said cavity end wall, said flange has a planar surface and said anode electrode is a metal wire and an end of said anode electrode wire projects above said planar surface of said flange structure and defines said anode contact surface.

20. The assembly of claim 19 wherein said coupling structure is of the screw-type and said resilient socket wipingly engages said coaxially upwardly projecting cathode wire and said annular contact wipingly engages said anode wire to complete electrical circuits when the threads of the screw type coupling structures are engaged and helically threaded together.