초록 ▼

A calorimetric sensor for sensing hydrocarbon emissions in an exhaust gas emission monitoring system is provided with at least first and second areas coated with different first and second catalysts so that one catalyst coated area produces oxidation with HC, CO and H.sub.2 and the other catalyst pr

A calorimetric sensor for sensing hydrocarbon emissions in an exhaust gas emission monitoring system is provided with at least first and second areas coated with different first and second catalysts so that one catalyst coated area produces oxidation with HC, CO and H.sub.2 and the other catalyst produces oxidation with CO and H.sub.2 but not with HC. Temperature increases attributed to the oxidation reactions are sensed by first and second RTDs while the temperature of an uncatalyzed sensor area is sensed by a reference RTD. Thermal temperature signals for each first and second RTD is balanced against the reference RTD signal to produce accurate first and second temperature signals which are then subtracted to produce a true signal of the HC concentration in the exhaust gas.

대표청구항 ▼

[ Having thus defined the invention, it is claimed:] [1.] An on-board monitoring system for detecting gaseous emissions produced by an internal combustion engine of a vehicle comprising:a) a catalytic converter through which exhaust gases pass;b) a sensor downstream of said converter for detecting h

[ Having thus defined the invention, it is claimed:] [1.] An on-board monitoring system for detecting gaseous emissions produced by an internal combustion engine of a vehicle comprising:a) a catalytic converter through which exhaust gases pass;b) a sensor downstream of said converter for detecting hydrocarbons present in said exhaust gas, said sensor havingi) at least first, second and third regions over which at least a portion of said exhaust gases pass;ii) a first catalyst in said first region and first sensing means associated with said first region for generating first electrical signals indicative of a characteristic of said exhaust gases;iii) a second catalyst in said second region and second sensing means associated with said second region for generating second electrical signals indicative of a characteristic of said exhaust gasesiv) third sensing means associated with said third region for generating reference electrical signals, said third region being void of catalyst;c) balance means receiving said first, second and third electrical signals and generating a composite signal indicative of at least one specific, gaseous component of said exhaust gases passing over said sensor;d) computer means in said vehicle for analyzing said composite signal to determine if said vehicle complies with emission regulatory standards; ande) a warning detector in said vehicle activated by said computer means if the emissions detected by said sensor exceed emission regulatory standards.