NO Detection by Pulsed Polarization of LambdaProbes–Influence of the Reference Atmosphere

Sensors

Maximilian Fleischer¹  Roland Pohle¹  Ralf Moos²  Sabine Fischer²  Daniela Schönauer-Kamin² 

[1] Corporate Technology, Siemens AG, Munich 81739, Germany;Department of Functional Materials, University of Bayreuth, Bayreuth 95440, Germany;

关键词: lambda probe;    UEGO;    NO sensor;    NOx sensor;    mixed potential;    YSZ;    pulsed polarization;    reference atmosphere;   

DOI  :  10.3390/s131216051

来源: DOAJ

【 摘 要 】

The pulsed polarization measurement technique using conventional thimble type lambda probes is suitable for low ppm NOx detection in exhaust gas applications. To evaluate the underlying sensor mechanism, the unknown influence of the reference atmosphere on the NO sensing behavior is investigated in this study. Besides answering questions with respect to the underlying principle, this investigation can resolve the main question of whether a simplified sensor element without reference may be also suitable for NO sensing using the pulsed polarization measurement technique. With an adequate sensor setup, the reference atmosphere of the thimble type lambda probe is changed completely after a certain diffusion time. Thus, the sensor response regarding NO is compared with and without different gas atmospheres on both electrodes. It is shown that there is still a very good NO sensitivity even without reference air, although the NO response is reduced due to non-existing overlying mixed potential type voltage, which is otherwise caused by different atmospheres on both electrodes. Considering these results, we see an opportunity to simplify the standard NOx sensor design by omitting the reference electrode.

【 授权许可】

Unknown