Dual-energy Computer Tomography and Digital Radiography Applications in Non-destructive Control of Materials

A multi-purpose home-made dual energy computer have been used to investigate a great diversity of object of scientific interest such as polymers containing variable proportion of fluor and sulfur, fragments of wood, sedimentary cores, as well as various rocks. By using a dedicated version of filtered back-projection algorithm as well as a set of standard samples it was possible to determine both density and effective atomic number distribution over any section (planar or volumic) of investigated objects. In all cases, the maximum precision in determining the local density was about 3.5 % while effective atomic numbers were calculated with an accuracy of 2%. At the same time, the spatial resolution of reconstructed tomographies was about 0.5 mm, while the analyses of images histograms allowed a better quantitative characterization of their internal composition