Patent ID: 8249818

Claim:
A method of qualifying the variability of the composition of an effluent, in which a succession of measurements is effected over time of at least one first physical-chemical parameter and one second physical-chemical parameter of the effluent, comprising the following actions at each time step: determining a first derivative for each of the first and second parameters; determining at least one second derivative between the first and second parameters; defining first logical domains for the first derivative of each of the parameters comprising at least one normal first logical domain corresponding to a normal variability of said first derivative and one abnormal first logical domain corresponding to an abnormal variability of said first derivative; assigning first probabilities of the first derivative of each of the parameters belonging to each of the first logical domains; defining second logical domains comprising at least one normal second logical domain corresponding to a normal variability of said second derivative and one abnormal second logical domain corresponding to an abnormal variability of said second derivative; assigning second probabilities of the second derivative belonging to each of the second logical domains; defining global logical domains on the basis of the first and second logical domains, the global logical domains comprising at least one normal global logical domain and one abnormal global logical domain; assigning global probabilities of the combination of the first derivatives of the parameters and at least one second derivative belonging to each of the global logical domains; and qualifying the variability of the composition of the effluent on the basis of said global probabilities.