Performance evaluation of NDE methods

Mathematical basis for the performance evaluation of Nondestructive Evaluation (NDE) methods is presented. In structural inspection with NDE methods, NDE data are not directly used for the condition assessment. Instead, NDE data must be interpreted as condition of inspected element. Correct assessments of conditions depend on many factors such as the inaccuracy and the variability in NDE measurements and the uncertainty in correlation between attributes (what is measured) and conditions (what is sought in the inspection). Inaccuracy and variability are the vulnerable nature of NDE methods, whereas uncertainty is the inevitable error introduced from attributes used by test device. Despite all the vulnerabilities using NDE methods, a reliable NDE method should provide correct assessment of condition, which may be the correct percent area damaged in an inspected element. To make the decision on the performance of NDE methods, this paper presents mathematical basis to measure the reliability of NDE methods.