A petrol/alcohol ratio sensor for flexible-fuel vehicles

A sensor, operating as a variable capacitance cell, has been developed for determining the ratio of methanol to petrol in fuel mixtures, through the measurement of the dielectric constant. When operated as part of a Digital Autoplex circuit, the sensor provides an approximately linear output across the full range of petrol/methanol mixture ratios, and is insensitive to variations in conductivity. The sensor is suitable for flexible-fuel vehicles which in the longer term should lead to a reduction in automotive pollution.<
>