Abstract: A method and apparatus for determining a volatility of a fuel sample. A fuel sample is collected in a container and heated for a time period using a heater device. Periodically during the heating, the capacitance of the fuel sample and the temperature of the heater device are determined. After a time period passes, the volatility of the fuel sample is determined using the capacitance decrease and the temperature increase. Specifically, a voltage across the heater device is used, along with the current through the heater device to determine the resistance of the heater device, which gives the temperature of the heater device and the sample. The capacitance and temperature are compared to values derived from experimentation for fuels of varying DI. The first measurement of capacitance with a known sample volume can be used to determine the MTBE or ethanol content in gasoline fuels.

Abstract: One embodiment of a method of fabricating a sensor element for an exhaust gas sensing device, comprises disposing an electrolyte in ionic communication with a sensing electrode and a reference electrode to form the sensor element. The sensing electrode comprises an activator comprising silica and an oxide of an element. The element is selected from the group consisting of alkaline earth elements, rare earth elements, and combinations comprising at least one of the foregoing elements.

Abstract: A gas sensor, comprising an oxygen pump cell with a first pump electrode and a second pump electrode disposed on opposite sides of a first solid electrolyte layer and a second pump electrode. The sensor also comprises an emf cell with an emf electrode and a reference gas electrode disposed on opposite sides of a second solid electrolyte layer. The emf electrode is disposed in fluid communication to the second pump electrode. A via hole is disposed through the first solid electrolyte layer, such that the first pump electrode is in fluid communication with the second pump electrode. A protective insulating layer, having a passage for gas to be sensed, is disposed in contact with the first pump electrode. A first insulating layer, having a conduit, is disposed in contact with the emf electrode. A second insulating layer, having an air channel, is disposed in contact with the reference gas electrode. A heater is disposed in thermal communication with the emf cell.

Abstract: The electrolyte comprises up to about 80 wt % zirconia, up to about 30 wt % stabilizer, and up to about 40 wt % dopant-zirconia. Alternatively, the electrolyte can comprise zirconia having a phase chemistry, wherein the phase chemistry, at about 25° C.

Abstract: A gas sensor is disclosed comprising an oxygen pump cell having at least one exterior pump electrode and at least one interior pump electrode disposed on opposite sides of a first solid electrolyte layer. An emf cell having a first and second emf electrodes and first and second reference gas electrodes are disposed on opposite sides of a second solid electrolyte layer. At least one insulating layer is in contact with the first and second emf electrodes. At least one via hole is disposed through the first solid electrolyte layer. At least one air channel is disposed through at least one insulating layer. An air vent is disposed in at least one insulating layer in contact with the first and second reference gas electrodes. A heater is disposed in thermal communication with the sensor. And at least five electrical leads are in electrical communication with said sensor. A method of using a gas sensor is also disclosed.

Abstract: A gas sensor for sensing NOx having electrochemical cells wherein dielectric material surrounds electrolytes except where electrodes are attached. Thereby, the exhaust gas is effectively prevented from contacting the electrolytes of the sensor's electrochemical cells. With the use of this technique, signal cross talk is minimized while enhancing NOx sensing sensitivity. Further, the total number electrodes needed are reduced which allows for more complex sensors structures.