Exhaust gas sensor and circuit configuration for the exhaust gas sensor

US5767386A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Bertrand Lemire · Schierling, DE
• Willibald Schuerz · Pielenhofen, DE

Key dates

• Filing date: Nov 22, 1996
• Grant date: Jun 16, 1998
• Expiry date: Nov 22, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

An exhaust gas sensor has first and second sensor elements. Exhaust gas surroundings of the first sensor element are catalytically activated, so that an oxygen partial pressure which is in equilibrium will always be measured by the first sensor element, regardless of the conversion capability of a catalytic converter. The exhaust gas surroundings of the second sensor element are separate from the exhaust gas surroundings of the first sensor element, so that the exhaust gas surroundings of the second sensor element are not catalytically active. As a function of the conversion capability of the catalytic converter, the second sensor element measures either an equilibrium oxygen partial pressure or a free oxygen partial pressure, which are of different magnitudes. A malfunction of the catalytic converter is detected by comparing measurement signals of the first and second sensor elements.