Abstract: A device is provided for improving the measuring accuracy of a process for determining the alcohol content and/or the calorific value of fuels by measuring the electrically measurable qualities of fuel. At least one component of the fuel system of an engine is used with a counterelectrode for the capacitive dielectric measurement of the fuel. At the same time, it is suitable to also use a component of the fuel system with respect to a counterelectrode for the measurement of the conductivity of the fuel. The same counterelectrode can be used for the dielectric measurement and for the measurement of conductivity of the fuel.

Abstract: A device for the determination of the alcohol content and/or the calorific value of fuels by measuring the characteristics of the fuel in a measurement cell in which a flow body that is at least partially wetted by the fuel is arranged. The accuracy and speed of this measurement is improved by providing a first electrode for the dielectric measurement of the fuel and a second electrode for the measurement of the conductivity of the fuel on the outside of the flow body. Preferably the first electrode for the measurement of the capacitance, its outer connection and the walls of the measurement cell form a mechanically rigid system. It can also be expedient to mount the measuring circuit for the measurement of at least the capacitance directly on the housing of the measurement cell.