Abstract: A sensor includes an electrode and a seed structure. The electrode is configured to measure current due to movement of particulate matter relative to the electrode. The seed structure is deposited on the electrode. The seed structure includes a plurality of elongated members extending outward from the surface of the electrode. The elongated members are configured to promote charge transfer to particles and/or agglomerates of the particulate matter during operation of the sensor.

Abstract: A method for analysis of a gas stream. The method includes identifying an affected region of an affected waveform signal corresponding to at least one characteristic of the gas stream. The method also includes calculating a voltage-current time differential between the affected region of the affected waveform signal and a corresponding region of an original waveform signal. The affected region and the corresponding region of the waveform signals have a sensitivity specific to the at least one characteristic of the gas stream. The method also includes generating a value for the at least one characteristic of the gas stream based on the calculated voltage-current time differential.

Abstract: A method for temperature analysis of a gas stream. The method includes identifying a temperature parameter of an affected waveform signal. The method also includes calculating a change in the temperature parameter by comparing the affected waveform signal with an original waveform signal. The method also includes generating a value from the calculated change which corresponds to the temperature of the gas stream.

Abstract: A device for signal processing. The device includes a signal generator, a signal detector, and a processor. The signal generator generates an original waveform. The signal detector detects an affected waveform. The processor is coupled to the signal detector. The processor receives the affected waveform from the signal detector. The processor also compares at least one portion of the affected waveform with the original waveform. The processor also determines a difference between the affected waveform and the original waveform. The processor also determines a value corresponding to a unique portion of the determined difference between the original and affected waveforms. The processor also outputs the determined value.

Abstract: A sensor includes an electrode and a seed structure. The electrode is configured to measure current due to movement of particulate matter relative to the electrode. The seed structure is deposited on the electrode. The seed structure includes a plurality of elongated members extending outward from the surface of the electrode. The elongated members are configured to promote charge transfer to particles and/or agglomerates of the particulate matter during operation of the sensor.

Abstract: A method is described. The method is a method for making a constraining ceramic assembly. The method includes applying at least one metallic electrode to a substrate. The method also includes applying a porous ceramic layer to the substrate to cover the metallic electrode. The method also includes sintering the substrate, the porous ceramic layer, and the metallic electrode together at a sintering temperature above a melting point of the metallic electrode.

Abstract: A device for signal processing. The device includes a signal generator, a signal detector, and a processor. The signal generator generates an original waveform. The signal detector detects an affected waveform. The processor is coupled to the signal detector. The processor receives the affected waveform from the signal detector. The processor also compares at least one portion of the affected waveform with the original waveform. The processor also determines a difference between the affected waveform and the original waveform. The processor also determines a value corresponding to a unique portion of the determined difference between the original and affected waveforms. The processor also outputs the determined value.

Abstract: A sensor includes an electrode and a seed structure. The electrode is configured to measure current due to movement of particulate matter relative to the electrode. The seed structure is deposited on the electrode. The seed structure includes a plurality of elongated members extending outward from the surface of the electrode. The elongated members are configured to promote charge transfer to particles and/or agglomerates of the particulate matter during operation of the sensor.

Abstract: A method is described. The method is a method for making a constraining ceramic assembly. The method includes applying at least one metallic electrode to a substrate. The method also includes applying a porous ceramic layer to the substrate to cover the metallic electrode. The method also includes sintering the substrate, the porous ceramic layer, and the metallic electrode together at a sintering temperature above a melting point of the metallic electrode.

Abstract: A device for signal processing. The device includes a signal generator, a signal detector, and a processor. The signal generator generates an original waveform. The signal detector detects an affected waveform. The processor is coupled to the signal detector. The processor receives the affected waveform from the signal detector. The processor also compares at least one portion of the affected waveform with the original waveform. The processor also determines a difference between the affected waveform and the original waveform. The processor also determines a value corresponding to a unique portion of the determined difference between the original and affected waveforms. The processor also outputs the determined value.

Abstract: A sensor includes an electrode and a seed structure. The electrode is configured to measure current due to movement of particulate matter relative to the electrode. The seed structure is deposited on the electrode. The seed structure includes a plurality of elongated members extending outward from the surface of the electrode. The elongated members are configured to promote charge transfer to particles and/or agglomerates of the particulate matter during operation of the sensor.

Abstract: A sensor assembly includes a voltage source, a sensor electrode, a grounded assembly, an integration capacitor, and a current meter. The sensor electrode is coupled to the voltage source to receive a voltage. The sensor electrode is disposed within a directed and controlled exhaust flow to facilitate particle agglomeration into particulate matter structures at a surface of the sensor electrode. The grounded assembly is coupled to a ground reference and disposed at a distance from the sensor electrode. The integration capacitor is coupled to a negative side of the voltage source to integrate in time current pulses from charge transfers from the sensor electrode of the particulate matter structures. The current meter is coupled to the voltage source to measure an integrated value of current supplied to the voltage source in response to charge transfers from the sensor electrode to the particulate matter structures in the exhaust flow.

Abstract: A sensor includes a housing, a central sensor electrode assembly, an insulating member, and a trace. The central sensor electrode assembly is coupled to a supply side of a voltage source. The insulating member is coupled between the housing and the central sensor electrode assembly. The insulating member circumscribes a section of the central sensor electrode assembly. The trace is coupled to the insulating member and circumscribes the section of the central sensor electrode assembly. The trace directs at least a portion of leakage current away from a voltage ground offset on an opposite side of the central sensor electrode assembly.

Abstract: A sensor includes a housing, a central sensor electrode assembly, an insulating member, and a trace. The central sensor electrode assembly is coupled to a supply side of a voltage source. The insulating member is coupled between the housing and the central sensor electrode assembly. The insulating member circumscribes a section of the central sensor electrode assembly. The trace is coupled to the insulating member and circumscribes the section of the central sensor electrode assembly. The trace directs at least a portion of leakage current away from a voltage ground offset on an opposite side of the central sensor electrode assembly.

Abstract: A primary pump current is directed through a primary electrochemical cell system between first and second constant primary pump currents to direct a first ion flow into and out from a shared measuring chamber. A first output signal generated by the primary electrochemical cell system in accordance with a first ion concentration within the shared measuring chamber is detected. A second output signal generated by a secondary electrochemical cell system in accordance with a second ion concentration within the shared measuring chamber is also detected. Based on a relationship between the first and second output signals, a secondary pump current is directed through the secondary electrochemical cell system between first and second constant secondary pump currents to direct a second ion flow into and out from the shared measuring chamber.

Abstract: A mixed potential NOx sensor apparatus for measuring the total NOx concentration in a gas stream is disclosed. The NOx sensing apparatus comprises a multilayer ceramic structure with electrodes for sensing both oxygen and NOx gas concentrations and includes screen-printed metallized patterns that function to heat the ceramic sensing element to the proper temperature for optimum performance. This design may provide advantages over the existing technology by miniaturizing the sensing element to provide potentially faster sensor light off times and thereby reduce undesired exhaust gas emissions. By incorporating the heating source within the ceramic sensing structure, the time to reach the temperature of operation is shortened, and thermal gradients and stresses are minimized. These improvements may provide increased sensor performance, reliability, and lifetime.

Abstract: A sensor assembly to measure particulate matter is described. The sensor assembly includes a voltage source, a sensor electrode, a grounded assembly, an integration capacitor, and a current meter. The sensor electrode is coupled to the voltage source to receive a voltage. The sensor electrode is disposed within a directed and controlled exhaust flow within the sensor assembly to facilitate particle agglomeration into particulate matter structures at a surface of the sensor electrode. The grounded assembly is coupled to a ground reference and disposed at a distance from the sensor electrode. The integration capacitor is coupled to a negative side of the voltage source. The integration capacitor is configured to integrate in time current pulses from charge transfers from the sensor electrode of the particulate matter structures.

Abstract: An electrode assembly for a particulate matter sensor in a gas environment. The electrode assembly includes an insulating tube, a conductor, and a positioning structure. The insulating tube has an outer surface and defines an interior cavity with an interior surface. The conductor is disposed within the interior cavity of the insulating tube. The conductor is electrically coupled to an electrode at a first end of the insulating tube and includes a contact portion at a second end of the insulating tube for connection to an external conductor. The positioning structure is coupled to the conductor. The positioning structure mechanically supports the conductor at a distance from the interior surface of the insulating tube to at least partially define an air dielectric gap at approximately a heater location corresponding to a heater.

Abstract: An apparatus, system and method maximizes efficiency and accuracy of measuring an ion concentration of a measured fluid by varying a flow of ions within a measuring cell in accordance with an output signal of a sensor cell. The pump current through a pump cell is switched between a constant positive current and a constant negative current when upper and lower thresholds of the output signal are reached. The pulse width ratio of the square wave produced by the varying current is compared to a pulse width ratio function derived from a calibration procedure to determine the ion concentration of the measured fluid. In one embodiment, the functions of the pump cell and sensing cell are performed by a single electrochemical cell.