Abstract: A system for measuring in-cylinder parameters utilizing an image charge measured in an engine cylinder by an in-cylinder pressure sensor due to chemi and or thermal ionization in Engine. The in-cylinder pressure sensor includes a sensing element, which is a metal sensor probe with a selective coating (e.g., metal, oxides of metal, native oxides, semiconductor, oxides of semiconductors, ceramics, glass, dielectric, etc., in the form of a coating on the metallic probe, tube, etc) in order to function in harsh, corrosive and/or elevated temperature environments. The output of the sensor can be connected to a signal-conditioning unit, which includes a low noise differential charge amplifier with an auto offset correction circuit to measure fast varying signals. The signal out from the conditioning unit can be acquired utilizing a high-speed microcontroller-based data acquisition system with suitable software to analyze and estimate parameters such as, for example, in cylinder pressure and knocking.

Abstract: A low noise differential charge amplifier circuit for measuring discrete (e.g., pico coulomb) charges in noisy, elevated temperature and corrosive environments. An input stage of a differential charge amplifier circuit includes a twisted and or untwisted two pair cable with a grounded shield. One twisted and or untwisted pair can be connected to a sensor and a first charge amplifier and a second twisted and or/untwisted pair can be connected to a sensor electrical equivalent impedance circuit and or kept open and a second charge amplifier. The output from the charge amplifiers can be directed to a differential amplifier in order to provide an amplified sensor signal without external noise signal mainly from power supply mains. The differential amplifier and the charge amplifiers can include an auto offset correction circuit to reduce errors due to offsets.

Abstract: A single cell oxygen sensor apparatus and method are disclosed. An yttrium-based stabilized layer having electrical terminals connected to the yttrium-based stabilized layer can be provided on a substrate, wherein the yttrium-based stabilized layer is excitable by a constant current applied to the electrical terminals. A plurality of electrodes are located on a side of the yttrium-based stabilized layer and a plurality of heater elements located on said substrate opposite said yttrium-based stabilized layer. The heater elements can maintain the yttrium-based stabilized layer at a particular temperature. A cavity is formed and located between the yttrium-based stabilized layer and the heater elements. The partial pressure of oxygen can be measured by comparing the partial pressure of oxygen within the cavity with respect to the partial pressure of oxygen in the atmosphere external to the single cell oxygen sensor apparatus.

Abstract: An apparatus and method for packaging and operating a gas sensor for use in high temperature gas environments. A gas sensor can be configured, which includes a sensor element and a housing in which the sensor element is located. A parallel gas path can be configured form said housing, wherein said parallel gas path is based on the natural differential pressure with respect to the velocity of said gas. The parallel gas path is preferably vertical to provide a sufficient friction to soot particles compared to the gas, such that when a partial quantity of said gas reaches said sensor element, said soot particles are avoided by said sensor element.

Abstract: A system for measuring in-cylinder parameters utilizing an image charge measured in an engine cylinder by an in-cylinder pressure sensor due to chemi and or thermal ionization in Engine. The in-cylinder pressure sensor includes a sensing element, which is a metal sensor probe with a selective coating (e.g., metal, oxides of metal, native oxides, semiconductor, oxides of semiconductors, ceramics, glass, dielectric, etc., in the form of a coating on the metallic probe, tube, etc) in order to function in harsh, corrosive and/or elevated temperature environments. The output of the sensor can be connected to a signal-conditioning unit, which includes a low noise differential charge amplifier with an auto offset correction circuit to measure fast varying signals. The signal out from the conditioning unit can be acquired utilizing a high-speed microcontroller-based data acquisition system with suitable software to analyze and estimate parameters such as, for example, in cylinder pressure and knocking.

Abstract: A low noise differential charge amplifier circuit for measuring discrete (e.g., pico coulomb) charges in noisy, elevated temperature and corrosive environments. An input stage of a differential charge amplifier circuit includes a twisted and or untwisted two pair cable with a grounded shield. One twisted and or untwisted pair can be connected to a sensor and a first charge amplifier and a second twisted and or/untwisted pair can be connected to a sensor electrical equivalent impedance circuit and or kept open and a second charge amplifier. The output from the charge amplifiers can be directed to a differential amplifier in order to provide an amplified sensor signal without external noise signal mainly from power supply mains. The differential amplifier and the charge amplifiers can include an auto offset correction circuit to reduce errors due to offsets.

Abstract: A urea quality sensor includes an acoustic resonator in order to measure the accurate concentration of urea by measuring change in molecular weight. A change in molecular weight of urea proportionately affects the speed of sound. The change in the composition of the urea solution manifests itself as a change in frequency. The concentration of the urea solution can be determined based on the frequency data obtained as a result of the frequency measurement utilizing the acoustic wave sensor. The urea quality sensor can be used with an NH3 sensor in order to identify that the solution is urea.

Abstract: An apparatus and method for packaging and operating a gas sensor for use in high temperature gas environments. A gas sensor can be configured, which includes a sensor element and a housing in which the sensor element is located. A parallel gas path can be configured form said housing, wherein said parallel gas path is based on the natural differential pressure with respect to the velocity of said gas. The parallel gas path is preferably vertical to provide a sufficient friction to soot particles compared to the gas, such that when a partial quantity of said gas reaches said sensor element, said soot particles are avoided by said sensor element.

Abstract: A single cell oxygen sensor apparatus and method are disclosed. An yttrium-based stabilized layer having electrical terminals connected to the yttrium-based stabilized layer can be provided on a substrate, wherein the yttrium-based stabilized layer is excitable by a constant current applied to the electrical terminals. A plurality of electrodes are located on a side of the yttrium-based stabilized layer and a plurality of heater elements located on said substrate opposite said yttrium-based stabilized layer. The heater elements can maintain the yttrium-based stabilized layer at a particular temperature. A cavity is formed and located between the yttrium-based stabilized layer and the heater elements. The partial pressure of oxygen can be measured by comparing the partial pressure of oxygen within the cavity with respect to the partial pressure of oxygen in the atmosphere external to the single cell oxygen sensor apparatus.

Abstract: A NOx gas sensor for measuring NO, NO2 and NOx gas content from automotive exhaust including a method for producing such a gas sensor. The NOx gas sensor generally includes a substrate, and a plurality of electrodes preformed and located on one side of the substrate. A platinum heater is located the other and opposite side of the substrate. A coating of nano-crystalline powders of a semi-conducting oxide material can be located and configured on the plurality of electrodes preformed on the substrate, thereby forming a gas sensor for the detection of NOx. The substrate may be composed of a ceramic material, glass, alumina and/or another type of high-melting material. The electrodes, along with the heater are preferably composed of platinum. The semi-conducting oxide material preferably comprises YMnO3 or doped YMnO3.

Abstract: A sensor assembly for measuring a gas parameter includes a sensing element cover. A bottom wall and the sidewall of the cover have openings configured such that, when the cover is attached to the the sensor so as to surround the sensing element and gas is flowing into the cover interior via the sidewall opening, the gas flow in the cover interior is drawn in a downward motion and concentrated in the vicinity of the sensing element. The openings can be configured to promote rotary or swirling movement of the gas flow in the cover interior. Also, the cover can have an outer cover surrounding an inner cover and the outer cover can have openings only on the cover upstream side to concentrate flow into the inner cover. The sensor assembly can be orientated in an operating position using an orientation pin located on the sensor assembly.