Miniature probe containing multifunctional electrochemical sensing electrodes

Claim 2

A MINIATURE PROBE COMPRISING A CARBON DIOXIDE SENSOR AND A PH ELECTRODE, THE CARBON DIOXIDE SENSOR COMPRISING A FLEXIBLE, ELONGATED FIRST ELECTRODE WIRE, A FIRST ELECTROCHEMICALLY ACTIVE MATERIAL ADHERING TIGHTLY TO AND IN ELECTRICAL CONTACT WITH AT LEAST A PORTION OF THE FIRST ELECTRODE LEAD WIRE, THE FIRST ELECTROCHEMICALLY ACTIVE MATERIAL RESSPONSIVE TO CHANGES IN PH, A SECOND ELECTRODE LEAD SURROUNDING AT LEAST PARTIALLY AND SPACED FROM THE FIRST ELECTRODE LEAD WIRE, A SECOND ELECTROCHEMICALLY ACTIVE REGION OF SILVER AND A SILVER HALIDE EXCEPT FLUORIDE ON A PORTION OF THE SECOND ELECTRODE LEAD, A LAYER OF ELECTRICAL INSULATING DISPOSED BETWEEN THE FIRST ELECTRODE LEAD WIRE AND THE SECOND ELECTRODE LEAD, AND ELECTROLYTE CONTACTING BOTH ELECTROCHEMICALLY ACTIVE MATERIALS, AND AN OUTER SHEATH OF CARBON DIOXIDE PERMEABLE, ION-IMPERMEABLE DIFFUSION BARRIER MATERIAL ENCAPSULATING AT LEAST THE ELECTROCHEMICALLY ACTIVE REGIONS AND THE ELECTROLYTE; AND A SECOND PH ELECTRODE COMPRISING A SEPARATE SECOND PORTION OF THE FIRST ELECTRODE LEAD WIRE WHICH IS EXPOSED EXTERIORLY OF THE OUTER SHEATH FOR CONTACT WITH A SAMPLE TO BE TESTED FOR CARBON DIOXIDE CONTENT AND HYDROGEN ION ACTIVITY, A THIRD ELECTROCHEMICALLY ACTIVE REGION ADHERING TIGHTLY TO AND IN ELECTRICAL CONTACT WITH THE EXPOSED PORTION OF THE FIRST ELECTRODE LEAD WIRE, THE THIRD ELECTROCHEMICALLY ACTIVE MATERIAL RESPONSIVE TO CHANGES IN PH, AND THE THIRD ELECTROCHEMICALLY ACTIVE REGION INSULATED ELECTRICALLY FROM THE SECOND ELECTROCHEMICALLY ACTIVE REGION.

Claim 3

A miniature probe as in claim 1, in which the first electrode lead wire comprises a base member, an exterior surface of a metal selected from the class consisting of palladium and iridium on the base member, and the first electrochemically active material is the respective oxide of the exterior surface metal.

Claim 4

A miniature probe as is claim 1, in which the outer sheath is a silicone-polycarbonate block copolymer.

Claim 5

A miniature probe as in claim 1, in which the electrolyte is an immobilized aqueous solution.

Claim 6

A miniature probe as in claim 1, in which the electrolyte is an anion exchange resin material of quaternized polystyrene partially in its bicarbonate form and partially in its chloride form.

Claim 7

A miniature sensor device comprising a carbon dioxide sensor and a pH sensor, the carbon dioxide sensor comprising a flexible, elongated first electrode lead wire, a first electrochemically active material adhering tightly to and in electrical contact with at least a portion of the first electrode lead wire, the first electrochemically active material responsive to changes in pH, a second electrode lead surrounding at least partially and spaced from the first electrode lead wire, a second electrochemically active region of silver and a silver halide except fluoride on a portion of the second electrode lead, a layer of electrical insulation disposed between the first electrode lead wire and the second electrode lead, an electrolyte contacting both electrochemically active materials, and an outer sheath of carbon dioxide permeable, ion-impermeable diffusion barrier material encapsulating at least the electrochemically active regions and the electrolyte; and a pH sensor comprising a separate second portion of the first electrode lead wire which is exposed exteriorly of the outer sheath for contact with a sample to be tested for carbon dioxide content and hydrogen ion activity, a third electrochemically active region adhering tightly to and in electrical contact with the exposed portion of the first electrode lead wire, the third electrochemically active material responsive to changes in pH, the third elelctrochemically active region insulated electrically from the second electrochemically active region, and a second reference electrode having an electrochemically active portion in insulating spaced relationship to and adapted for electrolytic connection to the third electrochemically active region.

Claim 8

A miniature sensor device comprising a carbon dioxide sensor and a pH sensor, the carbon dioxide sensor comprising a flexible, elongated first electrode lead wire, a first electrochemically active material adhering tightly to and in electrical contact with at least a portion of the first electrode lead wire, the first electrochemically active material responsive to changes in pH, a second electrode lead surrounding at least partially and spaced from the first electrode lead wire, a second electrochemically active region of silver and a silver halide except fluoride on a portion of the second electrode lead, a layer of electrical insulation disposed between the first electrode lead wire and the second electrode lead, an electrolyte contacting both electrochemically active materials, and an outer sheath of carbon dioxide permeable, ion-impermeable diffusion barrier material encapsulating at least the electrochemically active regions and the electrolyte; and a pH sensor comprising a separate second portion of the first electrode lead wire which is exposed exteriorly of the outer sheath for contact with a sample to be tested for carbon dioxide content and hydrogen ion activity, a third electrochemically active region adhering tightly to and in electrical contact with the exposed portion of the first electrode lead wire, the third electrochemically active material responsive to changes in pH, the third elelctrochemically active region insulated electrically from the second electrochemically active region, and a second reference electrode having an electrochemically active portion in insulating spaced relationship to and adapted for electrolytic connection to the third electrochemically active region.

Claim 9

A miniature probe as in claim 6, in which the first electrode lead wire comprises a base member, an exterior surface of a metal selected from the class consisting of palladium and iridium on the base member, and the first electrochemically active material is the respective oxide of the exterior surface metal.

Claim 10

A miniature sensor device as in claim 6, in which the second reference electrode is of silver-silver halide except fluoride and is spaced from the other elements of the device.