Oxygen sensor

Claim 2

A CHEMICALLY BIASED OXYGEN SENSOR COMPRISING OF A FIRST ELECTRODE OF PLATINUM, AN ELECTRICAL LEAD CONNECTED TO THE FIRST ELECTRODE, A SECOND ELECTRODE SPACED FROM THE FIRST ELECTRODE, A SECOND ELECTRODE COMPRISING SILVER WITH AT LEAST A PARTIAL LAYER OF SILVER HALIDE THEREON, AN ELECTRICAL LEAD CONNECTED TO THE SECOND ELECTRODE, AN AQUEOUS PH 5 BUFFERED ELECTROLYTE SOLUTION CONTAINING A HALIDE SALT AND 0.5 TO 5.0 WEIGHT PERCENT OF AN OXIDIZABLE FUEL SELECTED FROM THE CLASS CONSISTING OF ALCOHOLS, ETHYLENE GLYCOL, GYLCEROL, AND POLYMERS CONTANING COH GROUPS CONTACTING AT LEAST A PORTION OF BOTH ELECTRODES, AND A HIGH IMPEDANCE VOLTMETER CONNECTED TO THE OPPOSITE ENDS OF THE ELECTRICAL LEADS.

Claim 3

A chemically biased oxygen sensor comprising of a first electrode of platinum, an electrical lead connected to the first electrode, a second electrode surrounding at least a portion of the first electrode, the second electrode comprising silver with at least a partial layer of silver halide thereon, an electrical lead connected to the second electrode, a first layer of electrical insulation deposited between the first and the second electrodes, a second layer of electrical insulation deposited over the second electrode, an aqueous pH 5 buffered electrolyte solution containing a halide salt and 0.5 to 5.0 weight percent of a oxidizable fuel selected from the class consisting of alcohols, ethylene glycol, glycerol, and polymers containing COH groups contacting at least a portion of the first electrode and the silver halide layer of the second electrode, an outer sheath of oxygen permeable, ion-impermeable diffusion barrier material encapsulating at least the aqueous buffered solution, at least a portion of the first electrode, and the silver halide layer of the second electrode in contact with the aqueous solution and a high impedance voltmeter connected to the opposite ends of the electrical leads.

Claim 4

A chemically biased oxygen sensor comprising of a first electrode of platinum, an electrical lead connected to the first electrode, a second electrode surrounding at least a portion of the first electrode, the second electrode comprising silver with at least a partial layer of silver halide thereon, an electrical lead connected to the second electrode, a first layer of electrical insulation deposited between the first and the second electrodes, a second layer of electrical insulation deposited over the second electrode, an aqueous pH 5 buffered electrolyte solution containing a halide salt and 0.5 to 5.0 weight percent of a oxidizable fuel selected from the class consisting of alcohols, ethylene glycol, glycerol, and polymers containing COH groups contacting at least a portion of the first electrode and the silver halide layer of the second electrode, an outer sheath of oxygen permeable, ion-impermeable diffusion barrier material encapsulating at least the aqueous buffered solution, at least a portion of the first electrode, and the silver halide layer of the second electrode in contact with the aqueous solution and a high impedance voltmeter connected to the opposite ends of the electrical leads.

Claim 5

An oxygen sensor as in claim 2, in which the first electrode is a platinum wire, the second electrode is silver with a partial layer of silver chloride thereon, the aqueous solution contains potassium chloride, 0.67 weight percent ethylene glycol, and a pH 5.0 phosphate buffer, the first insulation is of polyester resin lacquer, and the second insulation and the diffusion barrier are of silicone polycarbonate copolymer.