Methodology for NDA performance assessment

In the framework of the RandD programme of the Joint Research Centre of the Commission of the European Communities, a considerable effort is being dedicated to performance assessment of NDA techniques taking account of field conditions. By taking account of field conditions is meant measurement samples of the size encountered in practice and training which allows inspectors to design cost efficient verification plans for the real situations encountered in the field. Special laboratory facilities referred to as PERLA are being constructed for this purpose. These facilities will be used for measurement experiments and for training. In this paper, performance assessment is discussed under the headings of measurement capability and in-field effectiveness. Considerable emphasis is given to the role of method specific measurement error models. The authors outline the advantages of giving statistical error models a sounder basis in the physical phenomenology of the measurement method