Patent ID: 6099708
Filing Date: 2000-08-08
Classification: G01N

Abstract:
A three-electrode electrochemical sensor for detection of a gas in an atmosphere containing the gas, said sensor comprising a housing having an electrochemical gas sensor cell with an electrolyte and three electrodes bonded to conductive plastic, said electrodes being a sensing electrode, a reference electrode and a counter electrode, said electrodes being in an aligned, spaced apart, parallel relationship with the reference electrode located between the sensing and counter electrodes and separated therefrom by an electrically-insulating material, said reference electrode having a central orifice, each of said electrodes being a membrane formed from a fluoropolymer film having a layer adhered thereto of a fluoropolymer-impregnated catalyst, each of said layers of said electrodes being ultrasonically welded to conductive plastic, said layers of said electrodes being separated by absorbent material having an electrolyte absorbed therein, the absorbent material on opposed sides of the reference electrode being in contact through said orifice, the absorbent material between electrodes being partly hydrophilic and partly hydrophobic, the conductive plastic ultrasonically welded to said electrodes being connected to electrical connection means for detection of current passing through said electrodes, said housing being a leak-proof sealed housing and the electrical connection means connected to said conductive plastic being external to said housing.