Electrochemical oxygen sensor, particularly for use in the exhaust system of automotive-type internal combustion engines

US4277323A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Klaus Muller · Tamm, DE
• Helmut Maurer · Rodenbach, DE
• Ernst Linder · Mühlacker, DE
• Franz Rieger · Aalen, DE
• Bodo Ziegler · Stuttgart, DE

Key dates

• Filing date: Feb 14, 1980
• Grant date: Jul 7, 1981
• Expiry date: Feb 14, 2000

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E60/50
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To improve the response speed of an electrochemical oxygen sensor, particularly for automotive use, to sense the oxygen content in exhaust gases, and which can be operative either as a polarographic sensor (requiring application of a voltage thereto), or as a potentiometric sensor (having one catalytically active electrode and another which is less catalytically active), an elongated insulating carrier plate (29), for example of a ceramic, has layer electrodes (30, 31) applied to one major surface thereof and a layer of solid electrolyte material (32) over the electrodes, so that the electrodes will be embedded in the solid electrolyte material. The carrier plate (29) is of a material pervious to oxygen molecules. A gas-impervious insulating cover (33), for example of a ceramic glass, covers the layer of solid electrolyte material (32). A heating element (34) protected by a protective cover (35), for example of aluminum oxide, can be applied against the gas-impervious cover layer (33).