Unheated planar sensor element for determining the concentration of a gas component in a gas mixture

US6940287B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Helmut Weyl
• Jens Schneider · Anderson, US
• Detlef Heimann · Gerlingen, DE
• Thomas Wahl · Pforzheim, DE
• Hans-Joerg Renz · Echterdingen, DE
• Norman Hahn · Evergreen, US
• James Richard Waldrop · Belton, US
• Damien Barnes · Anderson, US
• Mike McCormick · Anderson, US
• John Day · Iowa City, US

Key dates

• Filing date: Mar 10, 2004
• Grant date: Sep 6, 2005
• Expiry date: Mar 10, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4071
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An unheated planar sensor element for determining the concentration of a gas component in a gas mixture, in particular the oxygen concentration in the exhaust gas of an internal combustion engine, has a sensor foil made of a solid electrolyte with an outer electrode exposed to the measuring gas, and an inner electrode exposed to a reference gas, as well as a reference-gas channel, which is covered by the sensor foil on one side and accommodates the inner electrode. To produce a small-volume, cost-effective unheated sensor element for use in small combustion engines having low power output yet sufficiently satisfactory measuring accuracy, the reference-gas channel is sealed on the underside by an additional sensor foil made of a solid electrolyte, and covered by an inner electrode lying inside the reference-gas channel and an outer electrode exposed to the measuring gas.