Sensor element for limiting current sensors for determining the .lambda. value of gas mixtures

US5098549A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl-Hermann Friese · Leonberg, DE
• Werner Grunwald · Gerlingen, DE

Key dates

• Filing date: Feb 27, 1990
• Grant date: Mar 24, 1992
• Expiry date: Feb 27, 2010

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4072
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor element for limiting current sensors for determining the .lambda. value of gas mixtures is proposed which has two interconnected inner pump electrodes (8 and 8') disposed opposite each other in a diffusion channel (7). The resulting increase of the effective surface at the beginning of the inner electrodes markedly reduces the disadvantageous electrode polarization which occurs in sensor elements having only one inner pump electrode. At the same time, a better utilization of the noble metal required to form the pump electrodes is achieved.