at Google ScholarTitle data
Geupel, Andrea ; Kubinski, David J. ; Mulla, Shadab ; Ballinger, Todd H. ; Chen, Hai-Ying ; Visser, Jacobus H. ; Moos, Ralf:
Integrating NOx Sensor for Automotive Exhausts : a Novel Concept.
2009
Event: The 8th Asian Conference on Chemical Sensors (ACCS 2009)
, 11.-14.11.2009
, Daegu, Korea.
(Conference item: Conference
,
Other
Presentation type)
Abstract in another language
In order to meet the future emissions regulations, NOx sensors with a high sensitivity and a low ppm detection range will be required. For that purpose, we propose a novel sensor concept: an integrating NOx sensor to accurately measure the very low NOx concentrations found downstream of the NOx after-treatment systems in modern diesel and lean-burn gasoline vehicles. The integrating sensor concept is especially suited for the challenging demands posed by the On-Board Diagnostics (OBD) requirements because it is measuring the accumulated NOx in the exhaust during a measurement period instead of the instantaneous low NOx concentration. Applied on an interdigitated electrode structure, the electrical impedance of a lean NOx trap (LNT) material is measured. The sensitive layer changes its impedance when the amount of NOx stored increases. The resistance is calculated using an RC equivalent circuit. The functionality of the integrating sensor concept is shown. The sensor signal increases uniformly during seven periods with equal NO while the resistance remains constant when no NO is present in the gas. This means that the stored NOx is not desorbed. The correlation between the total offered NOx amount (NO concentration multiplied with the duration of the NO steps) and the sensor response is linear at low loadings and becomes saturated at higher loadings. After NO exposition, the LNT-film has to be regenerated and a novel measurement cycle starts. Some cross effects towards other components present in the exhaust were also investigated and found out to be negligible.
Further data
| Item Type: | Conference item (Other) |
|---|---|
| Refereed: | Yes |
| Institutions of the University: | Faculties > Faculty of Engineering Science Faculties > Faculty of Engineering Science > Chair Functional Materials > Chair Functional Materials - Univ.-Prof. Dr.-Ing. Ralf Moos Faculties Faculties > Faculty of Engineering Science > Chair Functional Materials Profile Fields > Advanced Fields > Advanced Materials Research Institutions > Research Centres > Bayreuth Center for Material Science and Engineering - BayMAT Profile Fields Profile Fields > Advanced Fields Research Institutions Research Institutions > Research Centres |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 600 Technology, medicine, applied sciences > 620 Engineering |
| Date Deposited: | 26 May 2015 06:39 |
| Last Modified: | 11 Apr 2016 09:22 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/14250 |