Patent ID: 8597481
Filing Date: 2013-12-03
Classification: G01N

Abstract:
1. A gas sensor element comprising: a solid electrolyte body having ion conductivity characteristics and a cylindrical shape with a bottom part; a reference electrode formed on an inner surface of the solid electrolyte body; a detection electrode formed on an outer surface of the solid electrolyte body; an electrode protection layer covering the outer surface of the solid electrolyte body with the detection electrode, supporting noble metal catalyst, and through which a target detection gas passes; and a heater inserted in the inside of the solid electrolyte body and generating heat energy when receiving electric power, wherein a front part of the gas sensor element has a leg part and a bottom part, the leg part is formed in parallel to an axial direction of the gas sensor element and an outer profile of a cross section of the leg part which is perpendicular to the axial direction of the gas sensor has a straight line shape, and an outer profile of a cross section of the bottom part has a curved shape, the detection electrode is one of a full-surface electrode and a partial electrode, the full-surface electrode is formed on the entire of the outer surface of the solid electrolyte body, and the partial electrode is formed on the leg part of and not formed on the bottom part of the outer surface of the solid electrolyte body, and the bottom part of the electrode protection layer has a first temperature rising speed when the heater generates heat energy, the bottom part of the electrode protection layer having the first temperature rising speed has a first quantity of noble metal catalyst, and the leg part of the electrode protection layer has a second temperature rising speed when the heater generates heat energy, and the leg part of the electrode protection layer having the second temperature rising speed has a second quantity of noble metal catalyst, and the first temperature rising speed is higher than the second temperature rising speed, and the first quantity of noble metal catalyst is larger than the second quantity of the noble metal catalyst, wherein the electrode protection layer has a multi layer structure composed of at least a coating layer and a catalyst layer, and the coating layer is formed so that the coating layer is in contact with the detection electrode, and the catalyst layer is formed on the coating layer, and the thickness (T