Performance demonstration by ROC method

Abstract The question of the efficiency of a material testing system is important, when a competing or advanced system appears at the market. The comparison 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 human inspectors. A testing system in the field of NDT - for example weld inspection - often consists of several different devices and components (radiographic film, its irradiation and development, conventional inspection with a light box, human inspector). The demonstration of the performance of such a system with similar or advanced methods can be done by a statistical method, the ROC method. This quantitative measure for testing performance allows the comparison of complex NDT systems which will be demonstrated in detail by the comparison of conventional weld inspection with inspection of welds using the digitised image of the radiographs.