Patent ID: 7875164

Claim:
An in situ self-calibrating method for an electrochemical sensor configured to measure the concentration of at least one dissolved species in an aqueous medium, said sensor including a working electrode of micro-disc type and its counter electrode, and a reference electrode, connected to a potentiostat on the one hand, and a generating electrode and its counter electrode connected to a current source on the other hand, these electrodes defining a set being further connected to an electronic control unit, said method comprising the following steps: a first measurement of the current of the working electrode representative of the concentration of dissolved oxygen in the medium before applying a current to the generating electrode, applying an anode current with determined density and duration to the generating electrode to produce a defined increase in the local concentration of dissolved oxygen, a second measurement of the current of the working electrode taken after said duration and representative of the concentration of oxygen after the application of said anode current to the generating electrode, and computing from said first and second measurements, a calibration factor for said at least one dissolved species, which relates the oxygen concentration of the medium to be analyzed and the actually measured current between the working electrode and its counter electrode.