Patent ID: 7128057

Claim:
A device for determining the quality of fuel for an internal combustion engine, comprising: a pressure sensor for measuring the pressure in a fuel container; a temperature sensor for measuring the temperature in a fuel container; and an evaluation unit with inputs that are connected to the pressure sensor and the temperature sensor, for determining a quality value representing the fuel quality, wherein the evaluation unit determines the quality value as a function of the temperature and the pressure in the fuel container in that the evaluation unit, derives the quality value therefrom, wherein the evaluation unit comprises a first processing unit which has inputs that are connected to the pressure sensor and the temperature sensor and which determines, as a function of the pressure and temperature in the fuel container, a gas emission characteristic value representing the gas emission behavior of the fuel, and the evaluation unit comprises a second processing unit which has an input that is connected to the first processing unit and which determines the quality value of the fuel as a function of the gas emission characteristic value, wherein the first processing unit comprises a differentiator which determines the rate of change in the pressure in the fuel container.