Process and system for measuring the oxidation stability and/or the thermal stability of a fuel

A system for determining at least one of oxidation stability and thermal stability of a fuel, comprising:

• a) a device for performing an electrochemical impedance spectroscopy measurement in the fuel;
• and
• b) a device for determining a deposit mass forming in the fuel;
• and
• c) a processor for processing the measurement, the processor comprising a computer on which is implemented at least one joint analysis method for determining evolution over time of values of components of an equivalent electrical representation of the fuel determined from the electrochemical impedance spectroscopy measurements and of values of a variation of the deposit mass in the fuel with the at least one joint analysis method enabling detection of a deposit mass of the fuel.