Polarographic sensor

US5507174A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl-Hermann Friese · Leonberg, DE
• Hermann Dietz · Gerlingen, DE
• Werner Gruenwald · Gerlingen, DE

Key dates

• Filing date: Aug 2, 1994
• Grant date: Apr 16, 1996
• Expiry date: Aug 2, 2014

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B1/04
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A polarographic sensor for determining concentration of certain components including oxygen or combustible fractions, such as hydrocarbons, hydrogen and carbon monoxide, in the exhaust gas of an internal combustion engine, includes a pump cell having an anode, a cathode, and an oxygen ion-conducting solid electrolyte provided between the anode and the cathode, wherein the cathode is provided with a diffusion barrier, wherein the anode is provided with a diffusion barrier, and wherein the concentration of the certain components is determined by measurement of a limiting current through the electrolyte and across one of the diffusion barriers to the corresponding anode or cathode.