Total focusing method applied to probability of detection

The qualification of inspection processes is an integral part of the development methodology of existing and new inspection procedures. An essential aspect of demonstrating how the inspection method performs involves detection capability and discontinuity evaluation. The probability of detection (POD) determination is currently handled by manufacturing intentionally flawed coupons and by validating real flaw dimensions with destructive means. This destructive analysis is expensive to perform, but it also has the detrimental effect that the sample is no longer available for further testing. Novel non-destructive testing (NDT) technology, the total focusing method (TFM), can be considered to speed up and reduce the cost of the qualification process by avoiding destructive analysis. The destructive analysis aims to obtain the precise dimensions of the flaws. However, this permanent damage would be avoided if non-destructive process could be applied to generate the same information, i.e., provide flaw dimensions required to produce POD data sets. This paper presents the motivation and a new methodology to generate POD curves based largely on TFM examinations to get the reference flaw size information. The result shows the feasibility of developing POD curves without destructive analysis and using the TFM to get flaw size data.