Arrangement for detecting the oxygen content in the exhaust gas of an internal combustion engine

US5549804A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gerhard Hotzel · Stuttgart, DE
• Harald Neumann · Lambach, DE
• Walter Strassner · Schorndorf, DE
• Johann Riegel · Bietigheim-Bissingen, DE

Key dates

• Filing date: Sep 30, 1994
• Grant date: Aug 27, 1996
• Expiry date: Sep 30, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4065
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention is directed to an arrangement for detecting the oxygen content in the exhaust gas of an internal combustion engine. The arrangement includes a concentration measuring cell operating pursuant to the Nernst principle. The concentration measuring cell has a measuring electrode, a solid electrolyte and a reference electrode and a series circuit which includes a direct voltage source and a series resistor. The series circuit connects the measuring electrode to the reference electrode. The measuring electrode communicates with the exhaust gas of the internal combustion engine and is connected to the reference electrode via the solid electrolyte. The reference electrode communicates with the reference gas volume. The reference gas volume is partitioned from the exhaust gas and from the ambient air so that a particle exchange between the reference gas volume and the exhaust gas as well as between the reference gas volume and the ambient air is at least made more difficult. The output voltage of the concentration measuring cell defines a measure for the difference of the oxygen concentrations in the exhaust gas of the engine and the reference gas volume. The output voltage of …