Method and arrangement for monitoring the operation of a gas probe

US6034610A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Eberhard Schnaibel · Hemmingen, DE
• Erich Junginger · Stuttgart, DE
• Lothar Raff · Waiblingen, DE

Key dates

• Filing date: Jul 13, 1998
• Grant date: Mar 7, 2000
• Expiry date: Jul 13, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4175
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention is directed to a method for monitoring the operation of a gas probe, such as a .lambda.-probe for an internal combustion engine. The .lambda.-probe has a probe ceramic (Nernst cell) and a probe heater. The internal resistance (x) of the probe ceramic is measured and a desired value (y) is determined in dependence upon the temperature of the gas to be detected and the heating power of the probe heater. The internal resistance (x) is then compared to the desired value (y) and, when the measured value of the internal resistance (x) exceeds the desired value (y), then a fault signal is generated and/or the fault signal is outputted and/or the fault signal is stored.