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:
Mar. 02, 2004
Filed:
May. 28, 2002
Bertrand Lemire, Schierling, DE;
Tim Walde, Regensburg, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A thick-film measurement sensor includes two measurement cells and is used to measure the NOx concentration in the exhaust gas from an internal combustion engine. The 1/&lgr; value of the exhaust gas is determined from an oxygen ion pump current flowing in the first measurement cell, for example, by a characteristic diagram, and, a measurement error, which can be used to correct the measured NOx concentration, is determined from this 1/&lgr; value, for example, by a characteristic curve that has previously been determined in a calibration measurement. The invention is based on the discovery that the measurement error is dependent on the air ratio in the exhaust gas. If this is expressed by the 1/&lgr; value, there is no need for a complex division calculation during the correction.