Device and method for measuring the spatial distribution of the concentration of compounds and mixtures thereof in a fluid and/or the level in a fluid

A method for measuring a concentration of oxygen in fuel systems of jet aircraft, characterized in that it comprises the following steps:

• a) irradiating a liquid fuel or a fuel present in a free volume of a fuel tank with excitation light at a temperature range between approximately-50° C. to about 50° C.;
• b) detecting an intrinsic fluorescence light emitted by the liquid fuel or by the fuel present in the free volume and arriving at a detector;
• c) digital processing of a signal obtained in the detector, to give a value of intensity or lifetime of the intrinsic fluorescence of the fuel;
• d) conversion of the intensity or lifetime of the intrinsic fluorescence of the fuel obtained into a concentration of oxygen through a calibration.

A method 1 for the measurement of a level of jet fuel in a tank, characterized in that it comprises the following steps:

• a) irradiating a liquid fuel of the tank with excitation light;
• b) detecting an intrinsic fluorescence light emitted by the liquid fuel and arriving at a detector;
• c) digital processing of a signal recorded in the detector, obtaining the intrinsic fluorescence intensity response of the fuel in response to a pulsed or modulated excitation;
• d) conversion of the obtained fluorescence signal of the fuel into the liquid level, through calibration and an algorithm.