Patent ID: 6558519
Filing Date: 2003-05-06
Classification: G01N

Abstract:
A gas sensor, comprising:a housing having disposed therein: at least one sensing electrode; at least one counter electrode; at least one test electrode; and at least one electrolyte in contact with at least one of said at least one sensing electrode, said at least one counter electrode and said at least one test electrode; wherein said housing permits at least a gas to be sensed to flow from an environment to said at least one sensing electrode; wherein said gas sensor is operable in a normal mode of operation in which said gas sensor detects whether said gas to be sensed is present at said at least one sensing electrode, and in a test mode of operation in which said at least one test electrode generates a test gas which flows to said at least one sensing electrode to enable an indication whether said gas sensor is operating correctly; wherein at least two of said at least one sensing electrode, said at least one counter electrode and said at least one test electrode are mounted side-by-side on a same side of a common porous gas permeable substrate to define a planar electrode assembly; and wherein said at least one sensing electrode and said at least one test electrode are mounted side-by-side on the same side of said common porous gas permeable substrate and are in contact with a common electrolyte.