Motorola Corporation

Engelhard Corporation

Continental Automotive Systems Corporation

Daniel A Young

Neil J Adams

Jeffrey D Naber

Donald J Remboski

Chowdary Ramesh Koripella

Adam Moya

Gerald Stephen Koermer

Jose P Joseph

Linda Hratko

Seajin Oh

Craig R Markyvech

Patrick W Blosser

Armand R Losinski

Stanley Wrzesinski

Gary K Mui

Edward Balko

Jie Xue

Adam Miller

Jeff Naber

Craig Markyvech

Chowdary R Koripella

Jeffrey Naber

Neil Adams

A method and apparatus for time domain reflectometry sensing of moisture in a test material. The sensor ( ) having a generally helical shaped electrode ( ) and at least one secondary electrode ( ) spaced apart from the generally helical shaped electrode ( ) to enable the test material to be present in the space ( ) between the helical shaped electrode ( ) and the secondary electrode ( ). A wave pulse generator ( ) is coupled to the generally helical shaped electrode ( ) and the secondary electrode ( ) that results in a reflection of the generated wave from the wave pulse generator ( ). Additionally, a reflected pulse detector ( ) is coupled to the generally helical shaped electrode ( ) and the secondary electrode ( ), in which the reflected wave pulse detector ( ) receives a reflected wave pulse from the wave pulse generator ( ). A controller that activates the wave pulse generator ( ) also controls a counter ( ) that records the delay between the generated wave pulse and reflected wave pulse from which the moisture content of the test material ( ) is determined.

Method and apparatus for time domain reflectometry moisture sensing in various media

A differential calorimetric gas sensor (10) which includes a sensing element (12) having a catalytic layer (14) disposed on a multi-layered substrate (26). Catalytic layer (14) includes an active catalyst region (14a) which oxidizes total combustibles within an exhaust gas stream and a reference catalyst region (14b) which oxidizes selective combustibles within the exhaust gas stream. An electrochemical oxygen source (18) is disposed on an opposite side of multi-layer substrate (26) from sensing element (12). An oxygen sensor cell (170) may be incorporated into electrochemical oxygen source (18). The multi-layered substrate (26) includes a plurality of overlaying insulating layers in which an intermediate layer (60) and a bottom layer (64) support primary heaters (58, 62), and in which another intermediate layer (52) supports compensation heaters (50a, 50b). The primary heaters (58, 62) function to maintain sensor (10) at a substantially constant temperature, while the compensation heaters (50a, 50b) function to restore temperature deviations determined by temperature-sensitive elements (46a, 46b) located on an inner layer (48) overlaying the compensation heaters (50a, 50b) resulting from the catalytic reactions taking place at the surfaces (34a, 34b) of the catalyst regions (14a, 14b). The control circuitry (300) operates to control the primary heater (58, 62) and the compensation heaters (50a, 50b), as well as to minimize the response variations of the temperature-sensitive elements (46a, 46b).

Exhaust gas sensor

A sensor housing (10) for directing the flow of a gas over two sensitive regions (53, 54) of sensing device (52) includes an inner shroud (12) surrounding the sensing device (52). The inner shroud (12) is inserted into an outer shroud (14), such that a plurality of gas channels (44) are formed between the inner shroud (12) and the outer shroud (14). In operation, a gas enters through inlet orifices (28) in the outer shroud (14) and travels through the gas channels (44) to the proximal end (26) of the inner shroud (12). The flow direction of the gas is then reversed and the gas passes through an inner chamber (50) and over sensitive regions (53), (54) located on the surface of the sensing device (52). Vacuum pressure created at an outlet hole (46) located at a distal end (35) of the outer shroud (14) draws the gas out of the inner chamber (50) and return the gas to the exterior of the sensor housing (10).

Sensor housing for a calorimetric gas sensor

A calorimetric hydrocarbon gas sensor (10) includes an electrochemical oxygen pump (18), a sensing element (12), and a multi-layered substrate (26) separating the sensing element (12) from the electrochemical oxygen pump (18). The multi-layered substrate (26) includes a plurality of overlying insulating layers, in which at least one intermediate layer (60) supports a first primary heater (58), and in which another intermediate layer (52) supports a temperature compensation heaters (50a, 50b). The primary heater (58) functions to maintain the calorimetric hydrocarbon gas sensor (10) at a constant, elevated temperature, while the active compensation heater (50a) functions to maintain substantially equal temperatures as determined by the thermometers (46a, 46b) located on an intermediate layer (48) overlying the compensation heaters (50a, 50b). Control circuitry is integrated with power measurement circuitry to measure differences in the heat produced by the compensation heater (50a) and the thermometer (46a) in an active region (100), and the heat produced by the compensation heater (50b) and the thermometer (46b) in a reference region (102).

Calorimetric hydrocarbon gas sensor

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).

System and method for measuring hydrocarbon conversion efficiency of a

A system and method estimates tailpipe emissions by sensing (703) a catalyzed gas stream (506) and providing a total-combustible gas signal (511) dependent thereon. The total-combustible gas signal (511) has a magnitude comprised of a first portion, dependent on a concentration of the hydrocarbon gas in the catalyzed gas stream (506), and a second portion, dependent on a concentration of the other combustible gasses in the catalyzed gas stream (506). A magnitude relationship between the first portion and the second portion is variable when the catalyzed gas stream (506) transitions into a region on the rich side of stoichiometry. The variability the magnitude relationship of the first and second portions is filtered out so that the magnitude relationship is substantially constant when the catalyzed gas stream (506) transitions into the region on the rich side of stoichiometry. The filtered signal is then integrated and compared to a threshold and an out-of-compliance signal (523) is provided when the filtered integrated signal (519) exceeds the threshold.

System and method for estimating tailpipe a emissions in a vehicle

A selective gas sensor (10) for detecting a particular compound, or group of compounds, such as non-methane hydrocarbons, within a high temperature gas stream (12) includes an oxygen generation system (14) positioned over an oxygen diffusion region (15). The oxygen generation system (14) and the oxygen diffusion region (15) provide oxygen through a medial temperature control zone (20) to a sensing element (16). The temperature and flux of hydrocarbon components within the high temperature gas stream (12) are regulated by components within the high temperature control zone (20) and by an external temperature control zone (22) in thermal contact with the sensing element (16).

Selective gas sensor

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Gurnee, IL, United States of America

Daniel A Young