Electrochemical oxygen sensor, particularly for use with exhaust gases of internal combustion engines, and especially for polarographic application

US4334974A · 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
• Karl-Hermann Friese · Leonberg, DE
• Harald Reber · Gerlingen, DE
• Hermann Dietz · Gerlingen, DE
• Hermann Ziener · Asperg, DE
• Friedrich Esper
• Gerhard Holfelder · Ditzingen, DE

Key dates

• Filing date: Feb 14, 1980
• Grant date: Jun 15, 1982
• Expiry date: Feb 14, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4067
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To permit a layer construction, which is inexpensive and lends itself to mass production manufacture, a solid electrolyte body, in plate-like construction, with electrodes at either thereof is positioned in a housing with a portion thereof extending in the region where it is exposed to gases to be sensed; a porous cover is applied on one of the electrodes, the porous cover having a predetermined diffusion resistance to oxygen molecules. A flat insulating plate of approximately the same dimension as the solid electrolyte plate is positioned flat thereagainst, and a flat layer-like electrical heating element is secured on the flat insulating plate or, in other embodiments, against another insulating covering on the other side of the heating element as well, close to the electrodes and adjacent the plane surfaces of the body. The heating element and the electrodes of the sensing element are carried out as conductive tracks for connection to respective sources of operating or biassing potential and, with respect to the sensing electrodes, to an evaluation circuit.