Abstract:
A method and apparatus for determining a volatility of a fuel sample. A fuel sample is collected in a container (22) and heated for a time period using a heater device (24). Periodically during the heating, the capacitance of the fuel sample and the temperature of the heater device (24) 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 (24) is used, along with the current through the heater device (24) to determine the resistance of the heater device (24), which gives the temperature of the heater device (24) 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:
Described is an electrical contact comprising a conductive surface of nickel, tin, or a precious metal having a surface of formed grains and particles of a low friction polymer deposited on a portion of the grains wherein the resistance of the contact is about 1 ohm or less, measured at about 100 mA, and wherein the polymer particles are deposited on the grains from a dispersion of the particles in a liquid.
Abstract:
An apparatus and method for determining an approximation to a measure of the volatility of fuel on-board a vehicle having an internal combustion engine. The method includes the steps of measuring at least one characteristic of the fuel (14) corresponding to a temperature of the fuel, a volume of the fuel, and a concentration of oxygenates within the fuel; determining an approximation of the a measure of the volatility of the sample volume of fuel (18, 20, 22, 24, 26, 28, 30) using a linear function based on the at least one measured characteristic of the fuel corresponding to temperature, volume, and concentration of oxygenates of the fuel. Preferably, at least one temperature measurement is associated with a predetermined volume of the sample as the sample is evaluated. The method can include determining whether a fuel contains ethanol (18), and if not, whether the fuel is a winter blend of fuel (26) or a summer blend of fuel (30). The method to determine whether ethanol is present can include the steps of bringing the fuel into contact with a sensing element (18A); measuring a characteristic of the fuel corresponding to concentration of oxygenates (18B), such as the change in capacitance or resistance of the sensing element; and calculating the dielectric constant or the conductivity of the sample respectively (18C). The method to determine the type of non-ethanol containing fuel can be based on two temperature measurements taken at two predetermined volumes during the evaporation process (16, 18, 22, 24, 26, 28).
Abstract:
An apparatus and method for determining an approximation to a measure of the volatility of fuel on-board a vehicle having an internal combustion engine. The method includes the steps of measuring at least one characteristic of the fuel (14) corresponding to a temperature of the fuel, a volume of the fuel, and a concentration of oxygenates within the fuel; determining an approximation of the a measure of the volatility of the sample volume of fuel (18, 20, 22, 24, 26, 28, 30) using a linear function based on the at least one measured characteristic of the fuel corresponding to temperature, volume, and concentration of oxygenates of the fuel. Preferably, at least one temperature measurement is associated with a predetermined volume of the sample as the sample is evaluated. The method can include determining whether a fuel contains ethanol (18), and if not, whether the fuel is a winter blend of fuel (26) or a summer blend of fuel (30). The method to determine whether ethanol is present can include the steps of bringing the fuel into contact with a sensing element (18A); measuring a characteristic of the fuel corresponding to concentration of oxygenates (18B), such as the change in capacitance or resistance of the sensing element; and calculating the dielectric constant or the conductivity of the sample respectively (18C). The method to determine the type of non-ethanol containing fuel can be based on two temperature measurements taken at two predetermined volumes during the evaporation process (16, 18, 22, 24, 26, 28).
Abstract:
A method and apparatus for determining a volatility of a fuel sample. A fuel sample is collected in a container (22) and heated for a time period using a heater device (24). Periodically during the heating, the capacitance of the fuel sample and the temperature of the heater device (24) 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 (24) is used, along with the current through the heater device (24) to determine the resistance of the heater device (24), which gives the temperature of the heater device (24) 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.