Method for characterizing compounds of interest in a measuring chamber having a variation in relative humidity

A method for characterizing compounds of interest introduced into a measuring chamber of an electronic nose comprising at least one sensitive site having receptors with which the compounds of interest are able to interact through adsorption/desorption, the method comprising:

• injecting, into the measuring chamber:
• in a first phase P1, a first gas sample formed of a carrier gas without the compounds of interest;
• and
• in a second phase P2 following the first phase P1, a second gas sample formed of at least the carrier gas and of the compounds of interest;
• determining, in the first and second phases P1 and P2, a measurement signal (Sk(ti)) representative of interactions between the gas sample present and the receptors of the sensitive site (6k), at various measurement times ti, in response to an excitation signal issued at the sensitive site (6k);
• measuring:
• a value φ1 of relative humidity φ in the measuring chamber in the first phase P1, and
• a value φ2 of relative humidity in the second phase P2, the value of relative humidity in the second phase φ2 being different from the value of relative humidity in the first phase φ1;
• determining a corrective parameter ({tilde over (S)}kref|φ2;
• Δ{tilde over (S)}kref|Δφ) associated with the sensitive site (6k), based on:
• at least the measured value φ2 of the relative humidity in the second phase, and
• a predetermined calibration function (fk, hk) associated with the sensitive site (6k), the predetermined calibration function (fk, hk) expressing a variation in a parameter ({tilde over (S)}kref;
• Δ{tilde over (S)}kref) representative of the measurement signal associated with the first gas sample as a function of the relative humidity (φ;
• Δφ);
• and
• determining a useful signal (Suk(tiϵP2)) by correcting the measurement signal (Sk(tiϵP2)) associated with the second gas sample based on at least the determined corrective parameter ({tilde over (S)}kref|φ2;
• Δ{tilde over (S)}kref|Δφ), and characterizing the compounds of interest based on the useful signal (Suk(tiϵP2)).