Page 6 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

Methods for Monitoriw and Diamosiw the Efficiencv of Catalvtic
Converters

Summary

The evolution of methods concerned with on-board (OBD) and non-OBD monitoring and
diagnosing of efficiency of catalytic converters of internal combustion engines is described
based on patents and published patent applications. Non-patent references are also used.

The basic principles of modem catalytic converters are described in an extensive Introduction,
where the importance of monitoring and diagnosing the efficiency of catalytic converters is
demonstrated.

The book is divided into four parts. The first part describes methods involving the use of
oxygen or airhel ratio exhaust gas sensors to determine the oxygen storage capacity of a
catalytic converter. The second part describes methods involving the use of temperature
sensors to determine the exothermic reaction capacity of a catalytic converter. The third part
describes all other methods existing in patent literature that monitor and diagnose the efficiency
of catalytic converters. The great majority of the methods of the third part involves exhaust gas
concentration measurements. The fourth part comprises a general discussion of all methods
described.
In the beginning of each part, a short introduction is given to explain the problem that the
methods attempt to solve. The methods in each part are presented in chronological order per
patent applicant. This helps to evaluate how the patent applicant has improved his methods
over time.

A patent number index with information about the patent applicants, inventors, priorities and
patent-families, an inventor index, a company index and a subject index can be found at the end
ofthe book.