Capacitive sensor for measurement of a fuel wall film, particularly in an intake duct of an internal combustion engine

US5175505A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Horst Magenau · Gerlingen, DE
• Nikolaus Simon · Gerlingen, DE
• Heins-Erdam Bollhagen · Leonberg, DE
• Siegbert Steinlechner · Leonberg, DE
• Berthold Wocher · Gaiberg, DE

Key dates

• Filing date: Sep 26, 1991
• Grant date: Dec 29, 1992
• Expiry date: Sep 26, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B7/08
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A capacitive sensor includes a plurality of individual condenser elements, each of which consist of a first, preferably circular, electrode and a second, preferably surrounding ring-shaped, electrode, which are mounted on one side of a nonconducting support. A common conductor is connected to each of the first electrodes of condenser elements. A signal can be detected separately from each of the condenser elements via conductors connected separately to the individual second electrodes. To increase the sensitivity and to avoid interference, the remote side of the support opposite to the one side is provided with a third additional electrode, which is at ground potential and also acts as a shield for interfering couplings. The sensor is used for measurement of the fuel film thickness in the intake of an internal combustion engine.