Electrochemical exhaust gas oxygen sensor construction

US4187163A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Leo Steinke · Waiblingen, DE
• Helmut Weyl

Key dates

• Filing date: Dec 23, 1977
• Grant date: Feb 5, 1980
• Expiry date: Dec 23, 1997

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4062
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To prevent ingress of moisture, water, dirt, or other contamination into the interior of an exhaust gas sensor having an opening to provide for communication with ambient air to establish an oxygen reference level, a cover cap, preferably of metal, but which may be of plastic if extreme heat resistance is not required, is placed over the sensor, the cover cap being formed with a labyrinth which provides for communication between ambient air and the interior of the sensor, the labyrinth preferably being formed as a groove, especially a spiral groove, in the interior of the cap and having access to outside ambient air, the cap preferably being secured by means other than friction, such as a spot weld, an engagement catch or the like to the sensor housing.