The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 23, 1983
Filed:
Apr. 12, 1982
Roland Stahl, Freiberg, DE;
Hans-Martin Wiedenmann, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
To extend temperature range of solid electrolyte ion conductive-type gas sensors, particularly for the exhaust gases from internal combustion engines, and to prevent leakage currents between a heater element and the solid electrolyte body at temperatures just above the response temperature of the sensor, but below its normal operating temperatures, that is, even in the range of between 250.degree. C. to 400.degree. C., a layer-like shielding electrode (18,29) is provided, positioned between the solid electrolyte body (11,25) and the insulating layer (17,31). The shielding electrode is galvanically connected to the return line (21,33) of the heating element. In accordance with one embodiment, the shielding electrode and one of the operating electrodes, for example, the sensing electrode (29), can be the same metallic film or element applied to the sensor, with an additional electrical insulation layer (32) interposed in the region between the film electrode (29) and the solid electrolyte body (25), the heater element (16,30) being positioned with the interposition of the electrical insulating layer over the film electrode in that region. Preferably, the width of the respective insulating layers decreases in a direction away from solid electrolyte body. The system is applicable both to potentiometric, as well as polarographic-type sensors, of, selectively, closed tubular or plate-like construction, with electrodes exposed either to a reference gas or having, respectively, different catalytic activity.