Multi-gas sensor to detect simultaneously nitrogen oxides and oxygen

Title data

Herrmann, Julia ; Hagen, Gunter ; Kita, Jaroslaw ; Noack, Frank ; Bleicker, Dirk ; Moos, Ralf:
Multi-gas sensor to detect simultaneously nitrogen oxides and oxygen.
In: Journal of Sensors and Sensor Systems. Vol. 9 (2020) Issue 2 . - pp. 327-335.
ISSN 2194-878X
DOI: https://doi.org/10.5194/jsss-9-327-2020

Project information

Abstract in another language

Due to tightened emission limits, the efficiency of exhaust gas aftertreatment systems has to be further enhanced. Therefore, inexpensive and robust NOx sensors are required to be installed not only in automotive exhausts, but also in any other kind of combustion-based application. In this contribution, an impedimetric NOx sensor is presented. The impedance of a functional thick film (KMnO4, manufactured in a screen-printing technique on planar alumina substrates) depends selectively on the NOx concentration in the exhaust but shows a dependency on the oxygen concentration. Therefore, an additional temperature-independent resistive oxygen sensor structure was integrated on the same sensor platform. BFAT (BaFe0.74Al0.01Ta0.25O3−δ (BaFe0.74Al0.01Ta0.25O3−δ) was used for this purpose, and the measurement was conducted in the dc resistance mode. It serves not only to determine the oxygen concentration in the exhaust, but also to correct the oxygen dependency of the NOx sensor.