PERFORMANCE DEMONSTRATION BY ROC METHOD

The question of the efficiency of a material testing system is importa nt, when a competing or advanced system appears at the market. The com parison of the different systems can be done partly by the comparison of the technical specification of the systems, but not all parameters can be expressed by measured values, especially not the influence of h uman inspectors. A testing system in the field of NDT - for example we ld inspection - often consists of several different devices and compon ents (radiographic film, its irradiation and development, conventional inspection with a light box, human inspector). The demonstration of t he performance of such a system with similar or advanced methods can b e done by a statistical method, the ROC method. This quantitative meas ure for testing performance allows the comparison of complex NDT syste ms which will be demonstrated in detail by the comparison of conventio nal weld inspection with inspection of welds using the digitised image of the radiographs.