Apparatus for ascertaining the alcohol content or calorific value of a mixture by capacitance measurement

An apparatus for ascertaining the alcohol content or the calorific value of a fuel containing a mixture of alcohol and gasoline, comprising:

• an electrically conductive housing having inside walls;
• a removable plate disposed in said housing, said plate having a fuel side and an exterior side;
• said inside walls of said housing and said fuel side of said plate defining a fuel conduit in said housing;
• an electronic measuring circuit disposed in said housing apart from said fuel conduit;
• an electrically conductive sensor element extending from said plate into said fuel conduit, said sensor element being secured in said plate in an electrically insulated and hermetically sealed manner;
• wherein a part of said inside walls forms a first electrode and said sensor element forms a second electrode, said electrodes having a fixed geometric relationship with respect to one another to form a capacitor and being electrically connected with said measuring circuit, the fuel in said fuel conduit serving as a dielectric of said capacitor.