Resistance probe for determining gas compositions and method of producing it

US5334350A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl-Hermann Friese · Leonberg, DE
• Werner Gruenwald · Gerlingen, DE
• Hans-Martin Wiedenmann · Stuttgart, DE
• Gerhard Hoetzel · Stuttgart, DE

Key dates

• Filing date: Jun 19, 1992
• Grant date: Aug 2, 1994
• Expiry date: Jun 19, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A resistance probe is proposed for detecting gas compositions, particularly in the exhaust gases of internal combustion engines. This resistance probe has the advantage over prior art resistance probes that, with a short response time, it is considerably more aging resistant. This is accomplished in that the resistance layer configured as a semiconductor layer is introduced or sintered into recesses or slits provided for this purpose in the prefabricated sensor carrier body and above it is applied a porous, electrically non-conductive engobe or a protective layer structure in the form of a grid or raster. These measures enable the measuring gas to gain access to the semiconductor layer, but the semiconductor layer is simultaneously protected against corrosive, erosive and/or cavitative attacks from the exhaust gas.