Design and Construction of a Refractometer for Measuring Dielectric Constant of Fuels

The increased air pollution, explosions that will lead to injury/fatality as well as reduced fuel performance caused by adulterated/impure petroleum products are detectable and preventable. In this paper, a portable microcontroller-based refractometer petroleum purity tester for detecting adulterated/impure petroleum products by measuring the dielectric constant value of the liquids was designed and implemented, focusing on households. The design was based on the principle of lasers and photoconductivity (light dependent resistor). The device was calibrated for the following fuel products: Premium Motor Spirit (PMS), Automotive Gas oil (AGO) or diesel, House-Hold Kerosene (HHK) with a tolerance of ±0.02 from standard dielectric constant value of the liquids. The device was used to test unknown fuel samples. The refractive index of the measured fuel product was converted to dielectric value and compared with its standard dielectric constant (PMS = 2.0, AGO = 2.1, HHK = 1.8). The device was able to detect adulterated and non-adulterated fuel products. The device is suitable for households to make real time decision and avoid home accident.