| 摘要 |
A method and apparatus are described for detecting dissolved contaminants in an alcohol-gasoline mixture used for fueling an internal combustion engine and then indicating that the fuel mixture is of substandard quality when the degree of contamination reaches an unacceptable level. The resistivity of the fuel mixture, which varies as a function of the degree of contamination, is measured using a sensor positioned in the engine fuel supply line. When the measured resistivity of the fuel decreases below a threshold amount, an indication of substandard fuel quality is provided. The threshold amount may be a fixed constant, or its value may vary depending upon the proportion of alcohol to gasoline in the fuel mixture. The composition of the fuel mixture is determined by using a capacitive sensor to measuring the fuel dielectric constant. A separate resistive sensor may be used for sensing fuel resistivity, or the same sensor used for sensing the fuel dielectric constant can be switched between resistive and capacitive measuring circuitry.
|
