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Design of Experiments for Validating Probability of Detection Capability of NDT Systems and for Qualification of Inspectors

The capability of a testing system is established by application of various methodologies to determine the probability of detection (POD). One accepted metric of an adequate testing system is that there is 95% confidence that the POD is greater than 90% (90/95 POD). Design of experiments for validating probability of detection (DOEPOD) capability of nondestructive testing systems is a diagnostic tool providing detailed analysis of POD test data, guidance on establishing data distribution requirements and resolving test issues. DOEPOD demands utilization of observation of occurrences. The DOEPOD capability has been developed to provide an efficient and accurate methodology that yields observed POD and confidence limits for both hit/miss or signal amplitude testing. DOEPOD does not assume prescribed POD logarithmic or similar functions with assumed adequacy over a wide range of discontinuity sizes and testing system technologies, so multiparameter curve fitting or model optimization approaches to generate a POD curve are not required. DOEPOD applications for supporting inspector qualifications are discussed.

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