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.