Abstract: A method for in situ self-calibrating of an electrochemical sensor for measuring the concentration of one or more species in an aqueous medium. The method includes: taking a first measurement of the current of a working electrode representative of the concentration of dissolved oxygen in the medium, applying an anode current of predetermined density and duration to a generating electrode to produce a defined increase in the local concentration of the dissolved oxygen, taking a second measurement of the current of the working electrode representative of the concentration of oxygen after applying the anode current to the generating electrode, and computing from the first and second measurements a calibration factor for one or more species that relates the oxygen concentration of the medium to be analyzed and the actually measured current between the working electrode and its counter electrode.

Abstract: An electrode system for an electrochemical cell is provided, including a substrate, a measuring electrode connected to the substrate and formed from a number of electrically conducting and mutually connected microdisks, and a generating electrode formed from an electrically conducting sheet and having a diameter that is greater than that of the microdisks. In one implementation, the microdisks are provided in cavities in the substrate.

Abstract: A modular electrochemical cell having two interchangeable assemblies each with a support structure defining a cylindrical recess and having a fitting for connecting a pipe to the assembly. A disc-shaped electrode is arranged inside each recess and the assemblies are arranged relative to each other so that their respective electrodes face each other. A modular insert is inserted between the assemblies to define an open space between the electrodes and to distribute fluid to a plurality of openings spaced from each other along an edge of this open space. Securing members secure together the two assemblies and the modular insert, and passages in the support structures convey fluid between the fittings and the modular insert.

Abstract: The system concerns an electrode system for an electrochemical sensor, comprising, arranged on a conductive substrate (10), a plurality of micro-discs (22) electrically connected to the substrate and a generating electrode (20) insulated from the substrate by an insulating layer (14) and including a plurality of orifices (24) concentric with said micro-discs. A conductive layer (12) and connections (26, 28) enable to connect the electrodes to power sources. The generating electrode enables to modify locally, at the micro-discs, the concentrations of species present in solution opposite said electrodes.