System and method for measuring hydrocarbon conversion efficiency of a catalytic converter

摘要

A system and method measures hydrocarbon conversion efficiency of a catalytic converter (501). Total-combustible sensors (511, 521) are positioned to measure exhaust gas on both sides of the catalytic converter (501). Signals from these sensors (511, 521) have a magnitude comprised of a first portion, dependent on a concentration of the hydrocarbon gas in the gas stream, and a second portion, dependent on a concentration of the other combustible gasses in the gas stream, where a magnitude relationship between the first portion and the second portion is variable when the gas stream transitions into a region on the rich side of stoichiometry. The signals from these sensors (511, 521) are filtered so that a magnitude relationship between a first and second portion of the filtered signals is constant when the gas stream (506) transitions into the region on the rich-side of stoichiometry. Hydrocarbon conversion efficiency (529) is computed dependent on the filtered signals (515, 525).