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:
Jan. 29, 1985
Filed:
Apr. 27, 1984
Ernst Linder, Muhlacker, DE;
Helmut Maurer, Vaihingen, DE;
Klaus Muller, Tamm, DE;
Franz Rieger, Aalen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The linearity of response of a polarographic sensor, of the diffusion-limited current type, having a solid electrolyte (1) and being particularly adapted for measuring oxygen content in exhaust gases from combustion processes, is improved by providing the anode (2b) of the sensor's first, measuring cell with a constant, internal supply of reference oxygen. Preventing the oxygen concentration at the anode (2b) from fluctuating eliminates a non-linearity which would otherwise occur in the plot of oxygen concentration versus diffusion-limited current, as the fuel/air ratio of the mixture being combusted passes 1. The oxygen supply takes the form of a second, pumping cell (3a,3b) which can utilize the same solid electrolyte layer (1) as the first cell, and which pumps oxygen ions across the electrolyte to the second cell's anode (3b), where they become oxygen molecules and are directed through a duct (8) to the measuring cell's anode (2b). Excessive pressure in the duct (8) is prevented by providing small pores (10) in the surrounding glass cover (9) for outward diffusion of excess oxygen. A constant voltage is applied to both cells.