Oxygen sensor particularly useful in exhaust system of automotive engine

Abstract From the Canadian patent

A solid electrolyte tube closed at one end and two porous electrode layers respectively coated on the outer and inner surfaces of the electrolyte tube constitute a known oxygen concentration cell. A tubular metal shell encloses the electrolyte tube partly such that a closed end portion of the tube protrudes from the shell and that the outer electrode coating is locally in contact with the inside of the shell. To protect the open end of the electrolyte tube against splashing of water during use without interrupting the admission of atmospheric air as a reference gas into the inside of the electrolyte tube, a tubular cap member of a metal is coaxially fixed to and electrically connected at …