Patent ID: 6856937

Claim:
A method of determining the thickness of a biofilm developing on a support immersed in an aqueous medium where such a bioflim is developing, comprising the steps: a) continuously circulating the medium in an electrochemical cell comprising a reference electrode, an auxiliary electrode and at least one working electrode; b) interrupting the circulation of the medium and isolating the cell; c) introducing an electrochemical tracer in the medium present in the cell; d) circulating the medium+tracer solution in the cell so as to direct a let of the solution perpendicularly to the working electrode; e) measuring and recording the value of the limiting current for reducing the tracer, as a function of the hydrodynamic conditions at the surface of the working electrode; f) calculating the thickness of the porous bioflim layer at the surface of the electrode by applying the Koutecky-Levich equation, based on analyzing the transport of matter through the porous layer which relates the value of the limiting current for reducing the tracer to the flowrate of the solution; and wherein the electrochemical tracer is potassium ferricyanide.