Process for the determination of the exhaust gas temperature and of the air/fuel ratio lambda and a sensor arrangement for execution of the process

US6085575A · kind A · utility

Assignee

• Heraeus Electro-Nite International N.V. · BE

Inventors

• Karlheinz Wienand · Aschaffenburg, DE
• Edelbert Hafele · Karlsruhe, DE

Key dates

• Filing date: Sep 28, 1998
• Grant date: Jul 11, 2000
• Expiry date: Sep 28, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/407
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

According to the state of the art, either two separate sensor elements are generally used to determine the exhaust gas temperature and the air/fuel ratio, lambda, or the temperature and lambda readings are not taken simultaneously, at least at temperatures of less than 250.degree. C. In addition, sufficiently precise simultaneous measurement is only possible during stationary operation. The process according to the invention and the corresponding sensor arrangement now make it possible to obtain a precise temperature and lambda reading at a minimal degree of metrological complexity, especially under non-stationary conditions, in that a heated sensor, which exhibits a temperature-sensitive and oxygen-sensitive element on a carrier element, is used to measure the exhaust gas temperature, even at low temperatures with the heating system switched off, while a lambda reading is obtained simultaneously, with the latter being possible only at higher temperature ranges.