Page 48 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

30 Methods for Monitoring and Diagnosing the Efficiency of Catalytic Converters

A few elements of theory are presented in the beginning of each chapter to contribute to
better understanding of the described methods.

The original patent and non-patent literature available at the European Patent Office (EPO) i
Rijswijk, Netherlands was the main source of information used in this book. For the Japanes
patent literature the technical abstracts published in English by the Japanese Patent Office wer
used.

I Chapter I I Chapter2 I Chapter3
Method I Dual O2 I Temperature 1 HC, CO, NO,
I Sensor sensors I measurement

A-sensor Surface ionization, sensors. Calorimetric
Variable resistance sensors
Diagnosis Measurement of 02 Detection of HC or CO oxidation,
principle storage capacity exothermic heat NO, reduction
Suitable Hot engine. Variable, also All modes
operation Most of the times at transient operation
mode steady state operation

Table 7: Overview of on-board efficiency diagnosis methods of catalytic converters