2025 SMSI Bannerklein

B2.3 Impedimetric NOx Sensor for Exhaust Applications with Internal Lambda Correction

Event
SMSI 2021
2021-05-03 - 2021-05-06
digital
Band
SMSI 2021 - Sensors and Instrumentation
Chapter
B2 Gas Sensors II
Author(s)
J. Herrmann, G. Hagen, J. Kita, R. Moos - University of Bayreuth, Bayreuth (Germany), F. Noack, D. Bleicker - CPK Automotive GmbH&Co. KG, Münster (Germany)
Pages
115 - 116
DOI
10.5162/SMSI2021/B2.3
ISBN
978-3-9819376-4-0
Price
free

Abstract

Due to current developments in the automotive industry, more attention has to be paid to exhaust aftertreatment. Robust and cost-effective sensors for monitoring and controlling the exhaust aftertreatment systems are required, especially for NOx detection. We suggest an impedimetric NOx sensor which is fully manufactured in planar thick film technology. The impedance of a functional layer (KMnO4 supported on Al2O3) reacts selectively to the NOx concentration in the exhaust. However, this mechanism depends on the air-fuel-ratio (Lambda). For this reason, a resistive O2-sensitive functional layer (BFT) is additionally applied to the sensor element. Using this signal of the O2-sensitive functional layer, the existing lambda can be determined and thus the lambda dependency of the NOxsensitive
functional layer can be corrected.

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