Sensor element for limiting current sensors to determine the lambda value of gas mixtures

US5310472A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hermann Dietz · Gerlingen, DE
• Werner Grunwald · Gerlingen, DE
• Claudio De La Prieta · Stuttgart, DE

Key dates

• Filing date: May 16, 1991
• Grant date: May 10, 1994
• Expiry date: May 16, 2011

Classification

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

Abstract

Sensor element for limiting current sensors to determine the lambda value of gas mixtures, in particular of exhaust gases of internal combustion engines, having inner and outer pump electrodes disposed on a ceramic substrate, the inner pump electrode of which is accessible for the measurement gas supplied through a diffusion layer acting as a diffusion barrier; having a gas-tight cover layer above the diffusion layer and having conductor tracks for the pump electrodes is described, in which the diffusion layer is adjustable, to calibrate the sensor element. This adjustability is advantageously attained by embodying the side of the diffusion layer 5 oriented toward the measurement gas inlet opening as a zigzag-shaped adjustment zone 8, from which parts can be separated mechanically or by laser cuts. The invention makes comparatively simple calibration of sensor elements possible.