Sensors, Vol. 19, Pages 3559: Catalyst State Diagnosis of Three-Way Catalytic Converters Using Different Resonance Parameters —A Microwave Cavity Perturbation Study

Sensors, Vol. 19, Pages 3559: Catalyst State Diagnosis of Three-Way Catalytic Converters Using Different Resonance Parameters—A Microwave Cavity Perturbation Study Sensors doi: 10.3390/s19163559 Authors: Carsten Steiner Vladimir Malashchuk David Kubinski Gunter Hagen Ralf Moos Recently, radio frequency (RF) technology was introduced as a tool to determine the oxygen storage level of a three-way catalyst (TWC) for gasoline vehicles. Previous studies on the investigation of commercial catalysts mostly use only the resonant frequency to describe the correlation of oxygen storage level and RF signal. For the first time this study presents a comparison under defined laboratory conditions considering both, resonance frequency and also the quality factor as measurands. Furthermore, various advantages over the sole use of the resonant frequency in the technical application are discussed. Experiments with Ø4.66’’ catalysts and Ø1.66’’ catalyst cores with alternating (rich/lean) gas compositions showed that the relative change in signal amplitude due to a change in oxygen storage is about 100 times higher for the inverse quality factor compared to the resonant frequency. In addition, the quality factor reacts more sensitively to the onset of the oxygen-storage ability, and delivers precise information about the necessary temperature, which is not possible when evaluating the resonant...
Source: Sensors - Category: Biotechnology Authors: Tags: Article Source Type: research