1. A device forming an operating tool, for non-destructive testing, during or at an end of production, of iron or steel elongated products, the tool configured to extract information on possible defects in the product, from feedback signals that are captured, following selective excitation of transmitting ultrasound sensors according to a selected time rule, by receiving ultrasound sensors forming an arrangement with a selected geometry, mounted in ultrasound coupling with the product via an intermediary of a liquid medium, with relative rotation/translation movement between a pipe and the transducer arrangement, the operating tool comprising: a converter, capable of selectively isolating a digital representation of possible echoes in designated time windows, as a function of the relative rotation/translation movement, the representation including amplitude and time of flight of at least one echo, and of generating a parallelepipedic three dimensional (3D) graph; a transformer unit capable of generating a 3D image of possible defects in the pipe on the basis of the 3D graph and a database; a filter, capable of determining, in the images, presumed defect zones, and properties of each presumed defect; and an output stage configured to generate a product conformity or non-conformity signal, wherein the transformer unit comprises an unnecessary data removal element, a pinpointed zones filtering element, a simulator, and an interpretation unit.