Planar polarographic probe for determining the .lambda. value of gas mixtures

US5169512A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hans-Martin Wiedenmann · Stuttgart, DE
• Gerhard Schneider · Kirkland, US
• Kurt Bayha · Oberriexingen, DE

Key dates

• Filing date: Sep 18, 1990
• Grant date: Dec 8, 1992
• Expiry date: Sep 18, 2010

Classification

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

Abstract

A planar polarographic probe for determining the .lambda. value of gas mixtures, in particular of exhaust gases of internal combustion engines, having at least the following units: a pumping cell (A), a diffusion unit (B) with a diffusion resistance preceding a pumping electrode of the pumping cell (A) and, if necessary, a heating unit (C) is proposed in which the diffusion resistance of the diffusion unit (B) is formed by a preshaped body which becomes porous on sintering and which is inserted into the unsintered probe. Such a polarographic probe enables a sensor to be constructed in a simple manner which is particularly suitable for production, with increased reproducibility of the diffusion resistance.