Impedimetric NOx sensor for exhaust applications with internal lambda correction

Titelangaben

Herrmann, Julia ; Hagen, Gunter ; Kita, Jaroslaw ; Noack, Frank ; Bleicker, Dirk ; Moos, Ralf:
Impedimetric NOx sensor for exhaust applications with internal lambda correction.
2021
Veranstaltung: SMSI Sensor and Measurement Science International, Virtual Conference , 03-06 May 2021 , Nuremberg, Germany.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Vortrag )
DOI: https://doi.org/10.5162/SMSI2021/B2.3

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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 NOx-sensitive functional layer can be corrected.