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Differences in Pre- and Post-Converter Lambda Sensor Characteristics
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1996 by SAE International in United States
Annotation ability available
The two characteristics of wide-range air/fuel ratio sensors when located in front of and behind a three-way catalytic converter are investigated. Input as well as output gas concentration measurements and sensor readouts are presented. Behind a new converter almost no oxygen can be measured for rich air/fuel ratios.
The wide-range sensor's signal is sensitive to changes in the gas composition when keeping the air/fuel ratio constant at a rich value. Since the gas compositions up- and down-stream of the converter differ, the sensor signals are not identical for the same rich air/fuel ratio before and after the converter.
The various diffusion coefficients of the exhaust gas species flowing through the porous coating of the sensor combinded with the different up- and downstream gas compositions are responsible for the different sensor characteristics.
CitationGermann, H., Taglaiferri, S., and Geering, H., "Differences in Pre- and Post-Converter Lambda Sensor Characteristics," SAE Technical Paper 960335, 1996, https://doi.org/10.4271/960335.
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