Electrochemical sensor construction

US4019974A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Helmut Weyl
• Leo Steinke · Waiblingen, DE

Key dates

• Filing date: Dec 23, 1975
• Grant date: Apr 26, 1977
• Expiry date: Dec 23, 1995

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4078
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To provide for insulation between the conductors of a solid electrolyte ion-conductive oxygen measuring tube and a steel housing thereof, for introduction into the exhaust system of an automotive vehicle, the housing is formed with a shoulder against which a ceramic ring is seated, the tube passing through the ring, and likewise being formed with a shoulder seating against the ring. The outer conductor along the tube extends beyond the ring. A resilient electrically conductive mass such as graphite is packed around the tube, and spaced from the inner walls of the housing by a resilient mass of an insulating powder, such as talcum. The tube is held in position by a second insulating ring, the aperture of which is lined with a metallic sleeve contacting the electrically conductive powder and providing a contact connection to a terminal located in an end insulator secured to the housing; the interior of the tube is likewise connected to another terminal located in the insulator.