Method and device with separate emission/reception functions for making eddy current tests on an electrically conducting part

Method with separate emission/reception functions for making eddy current tests on an electrically conducting part (13) with an electrical conductivity σ1 and relative magnetic permeability μr1, in which a sensor comprising at least one assembly formed from at least one emission winding (11) emitting an electromagnetic field and at least one reception winding (12) influenced by the electromagnetic fields produced by eddy currents induced in this part (13), moves above this part, characterised in that it comprises the following steps:

• obtain a first complex voltage curve (20) at the terminals of a reception winding (12), depending on the distance between the corresponding emission winding (11) and this reception winding, for the nominal distance between the sensor and a portion of this part without any defects or another part without any defects,
• obtain at least one second complex voltage curve (21,22) at the terminals of a reception winding, as a function of the distance between the corresponding emission winding and this reception winding, for at least one distance (e) different from the nominal distance between the sensor and a portion of this part with no defects or another part without any defects,
• determine at least one given distance (di) that minimises the modulus of the difference between the first curve (20) and the at least one second curve (21, 22),
• calculate the arithmetic mean (d) of the at least one given distance (di),
• choose this arithmetic mean+/−20% as the distance between the two emission and reception windings
• detect if one or several defects are present in this part.