Portable oxygen sensor with shortened break-in time

Claim 1

A method of forming a preconditioned oxygen sensor cell which comprises providing a porous body of copper metal having a large surface area for its volume, distributing through said body of copper a quantity of cuprous oxide to constitute 0.1 to 5.0 percent of the weight of the body of copper, maintaining a level of porosity of said body of at least 15 percent by volume, and disposing said porous body in an oxygen sensor cell.

Claim 2

A method of forming a preconditioned oxygen sensor cell which comprises providing a porous body of copper metal having a large surface area for its volume, distributing through said body of copper a quantity of cuprous oxide to constitute 0.1 to 5.0 percent of the weight of the body of copper, maintaining a level of porosity of said body of at least 15 percent by volume, and disposing said porous body in an oxygen sensor cell.

Claim 4

A method of forming a preconditioned oxygen sensor cell which comprises providing a porous copper counter electrode, heating the counter electrode to a temperature between 100° and 200° C. in an atmosphere containing oxygen in an inert gas at a partial pressure well below that of air, continuing the heating until the porous copper counter electrode contains between 0.1 and 5.0% by weight of cuprous oxide, and installing the oxide-bearing counter electrode in an oxygen sensor cell.

Claim 5

A method of forming a preconditioned oxygen sensor cell which comprises providing a porous copper counter electrode, heating the counter electrode to a temperature between 100° and 200° C. in an atmosphere containing oxygen in an inert gas at a partial pressure well below that of air, continuing the heating until the porous copper counter electrode contains between 0.1 and 5.0% by weight of cuprous oxide, and installing the oxide-bearing counter electrode in an oxygen sensor cell.

Claim 8

The method of forming a preconditioned oxygen sensor cell which comprises providing a copper powder to be sintered, admixing with said powder between 0.1 and 5% by weight of cuprous oxide powder, hot-pressing the mixed powders at a temperature between 100° and 250° C. at a pressure of 1000 to 5000 psi for a period of about five minutes, sintering the hot pressed powder mixture at a temperature of 600° to 800° C. for a period of ten to twenty minutes and incorporating the counter electrode so formed into an oxygen sensor cell.

Claim 9

The method of forming a preconditioned oxygen sensor cell which comprises providing a copper powder to be sintered, admixing with said powder between 0.1 and 5% by weight of cuprous oxide powder, hot-pressing the mixed powders at a temperature between 100° and 250° C. at a pressure of 1000 to 5000 psi for a period of about five minutes, sintering the hot pressed powder mixture at a temperature of 600° to 800° C. for a period of ten to twenty minutes and incorporating the counter electrode so formed into an oxygen sensor cell.

Claim 11

A method of forming a preconditioned oxygen sensor cell which comprises providing a porous copper counter electrode, introducing the counter electrode into an electrochemical cell containing KOH solution, surrounding the counter electrode in said cell by a cylindrically wound sheet metal electrode and spacing said sheet metal uniformly from the counter electrode by a distance of one to two centimeters, connecting the counter electrode to the positive pole of a constant current source to make the counter electrode the anode of the electrochemical cell and connecting the sheet metal electrode as cathode of the electrochemical cell, passing a current of less than one milliampere through the cell for a period of time to produce from 0.1 to 5 weight percent cuprous oxide uniformly on the counter electrode, and inserting the oxide-bearing counter electrode into an oxygen sensing electrode.

Claim 12

A method of forming a preconditioned oxygen sensor cell which comprises providing a porous copper counter electrode, introducing the counter electrode into an electrochemical cell containing KOH solution, surrounding the counter electrode in said cell by a cylindrically wound sheet metal electrode and spacing said sheet metal uniformly from the counter electrode by a distance of one to two centimeters, connecting the counter electrode to the positive pole of a constant current source to make the counter electrode the anode of the electrochemical cell and connecting the sheet metal electrode as cathode of the electrochemical cell, passing a current of less than one milliampere through the cell for a period of time to produce from 0.1 to 5 weight percent cuprous oxide uniformly on the counter electrode, and inserting the oxide-bearing counter electrode into an oxygen sensing electrode.