1996-02-01

Differences in Pre- and Post-Converter Lambda Sensor Characteristics 960335

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.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Application of Vehicle Equipped with Ionic Current Detection System for the Engine Management System

970032

View Details

TECHNICAL PAPER

Observations of Trans-stoichiometric AFR Spikes in UEGO Sensors

2000-01-2837

View Details

TECHNICAL PAPER

Evaluation of an UV-Analyzer for the Simultaneous NO and NO2 Vehicle Emission Measurement

2004-01-1830

View Details

X