Method and station for the construction of a stator winding with rigid bars for a rotary electrical machine; an insulated wire of electrically conductor material and provided on the outside with an insulating layer is unwound from a coil. A final end of the insulated wire is bent in a “U” shape so as to create a bar having two legs connected to one another by a cusp. The insulated wire is transversely cut to separate the rigid bar from the remaining part of the wire; and the bar is inserted into a stator slot of a magnetic core of a stator. The electrical conductivity is measured between the core and the outer surface of the insulated wire by means of a first electrode electrically and permanently connected to the core of the insulated wire and a second electrode, which rubs against the outer surface of the insulated wire.