MAGNETIC CORROSION INDICATOR
An aspect of the invention relates to a corrosion indicator (1) for insertion in a porous coating of a wall, in particular of reinforced concrete, comprising at least one permanent magnet (10) generating a magnetic field, and a layer (12) that can be corroded by pathogens in particular chloride ions, the corrodable layer (12) being integral with the magnet, the corrodable layer (12) comprising a ferromagnetic material to allow the magnetic field generated by the magnet (10) to be modified depending on the state of corrosion of the corrodable layer (12).