Electro-chemical measuring sensor with a potential-free sensor element and method for producing it

US5670032A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl-Hermann Friese · Leonberg, DE
• Helmut Weyl
• Siegfried Nees · Lauffen am Neckar, DE
• Hans-Martin Wiedenmann · Stuttgart, DE

Key dates

• Filing date: Jan 25, 1996
• Grant date: Sep 23, 1997
• Expiry date: Jan 25, 2016

Classification

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

Abstract

An electro-chemical measuring sensor (10) for determining the oxygen content of gases, in particular for determining the oxygen content in exhaust gases of internal combustion engines, with a potential-free disposed sensor element (14). The sensor element (14) has an oxygen-ion-conducting solid electrolyte body (23), preferably in the shape of a pipe or tube closed at one end, which has an exterior electrode (25) disposed on the exterior surface with a strip conductor (27) on the side toward the contact and also extending on the exterior surface, and which is inserted by means of a sealing ring (20) in a metal housing (11). The sensor element (14) has an electrically insulating layer (21) at least in the area of the sealing ring (20), which covers at least the strip conductor (27) in the direction toward the housing (11). The insulating layer (21) is formed from a mixture of a crystalline, non-metallic material and a glass-forming material. In the course of production the insulating layer (21) is subjected to a thermal treatment above the melting temperature of the glass-forming material, in the course of which the insulating layer (21) forms a glaze filled with the crystalline, no…