Uncertainty and reliability of the nondestructive testing system

Nondestructive testing (NDT) is one of the quality control and maintenance inspection methods on mechanical structures. For prompting quality in the NDT system, the uncertainty and the reliability of the NDT system should be evaluated. In the laboratory accreditation, the uncertainty is accepted as the error index of the NDT system. In the MIL standard, the reliability of NDT is defined as the flaw detection probability of the NDT system. In this paper, the inspection reliability of the NDT system and uncertainty of measurements have been overall numerically described with the case study. The inspected dimensions of porosity on the electron beam weldments were inspected by the radiographic method, and the true dimensions by the metallography method were used for the analysis.