Patent ID: 8218722

Claim:
A method for scanning the internal quality of wooden elements ( 1 ) having a main direction of extension, such as logs or planks, comprising the operating steps of taking a wooden element ( 1 ) having a main direction of extension identifiable with a main axis of extension of it; irradiating the wooden element ( 1 ) with at least one beam ( 3 ) of electromagnetic radiation in one or more directions of irradiation which are transversal to the main axis of extension; creating a relative helicoidal movement between the wooden element ( 1 ) and the beam ( 3 ) of electromagnetic radiation, the relative movement having a first component which is a translation substantially parallel with the main axis of extension of the wooden element ( 1 ) and a second component which is a rotation substantially about the wooden element ( 1 ); during said movement, for a plurality of separate reciprocal positions of the wooden element ( 1 ) and the beam ( 3 ), using at least one detector ( 4 ) comprising a plurality of sensors to detect the residual intensity of at least part of the electromagnetic radiation which passed through the wooden element ( 1 ) and which, parallel with the main axis of extension, affects the wooden element ( 1 ) for a detection length (L); and reconstructing the internal structure of the wooden element ( 1 ) based on processing of the intensities detected for each reciprocal position; the method being characterized in that the step of creating a relative movement between the beam ( 3 ) and the wooden element ( 1 ) is carried out in such a way that the helix formed by the relative movement has a pitch P equal to Y times the sum of the detection lengths (L) of all of the detectors used, where Y≧5, and also being characterized in that the step of reconstructing the internal structure of the wooden element ( 1 ), at a cross-section of its main axis of extension, is at least implicitly carried out by dividing the volume of the wooden element ( 1 ) at the section to be reconstructed, into a plurality of basic volumes assumed to have constant density, each having a structure which is extended parallel with the main axis of extension in such a way that the dimension of each basic volume along the main axis of extension is equal to at least X times the detection length (L) of each detector used, where X≧5.