06699383 is referenced by 170 patents and cites 3 patents.

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.

Title
Method for determining a NOx concentration
Application Number
10/156483
Publication Number
6699383 (B2)
Application Date
May 28, 2002
Publication Date
March 2, 2004
Inventor
Tim Walde
Regensburg
US
Bertrand Lemire
Schierling
US
Agent
Ralph E Locher
US
Werner H Stemer
US
Laurence A Greenberg
US
Assignee
Siemens Aktiengesellschaft
US
IPC
G01N 27/407
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