Non-invasive Microwave Sensor for Ethanol Content in Gasoline Applications

The adulteration of gasoline has become a common practice in the process of its transportation, distribution and commercialization. Using non-compliant gasoline has many negative consequences for society including financial and health problems like gasoline overconsuming, decreasing engine performance, spontaneous combustion and increasing of pollutants emission. Therefore, several methods of complete gasoline analysis are available in the market, but many of these methods are only feasible in laboratories, requiring specialized people to gauge the quality of the product. Furthermore, non-invasive methods are not yet widely used to perform gasoline quality measurement, which is a further aggravation of gasoline handling throughout the entire testing and analysis process. Hence, considering that standard gasoline is a dielectric liquid mixture with about 30 different hydrocarbons, the present paper proposes a noninvasive method applied to gasoline quality measurement. This method is based on the variation of electrical parameters of the mixture, utilizing as the sensor a microwave resonator, once that varying dielectric parameters alter the power transmission in specific structures.