TY - GEN A1 - Maierhofer, Christiane T1 - A multi-parameter probability of detection (POD) model for flash thermography N2 - In most cases where a POD is calculated based on continuous data obtained by active thermography, the signal-to-noise ratio (SNR) of the signal, the difference of the defect signal to the background or the absolute signal is analyzed as a function of the aspect ratio (ratio of the size of a defect to its overage), although a distinct linear relationship on a linear or logarithmic scale could not be satisfactorily shown and is also not expected. Therefore, a multi-parameter probability of detection (POD) model was developed, where an รข versus a continuous signal analysis was based on the linear relationship between the SNR and a multi-parameter a. This POD model is based on data which were recorded within a flash thermography round robin test with nine participants. Metal test specimens with flat bottom holes (FBHs) were analyzed by calculating the SNR of the defect signatures in the thermograms as well as in the phase images as a function of defect parameters. The linear relationship of the experimental data to the multi-parameter a was verified by comparison to data obtained from an analytical model that is considering lateral thermal heat diffusion as well as to data obtained by numerical simulation. The resulting POD curves for the thermograms and phase images give an estimation for the detectability of the FBHs with known geometry in steel using different equipment and obtained by different participants. By comparing the SNRs of FBHs with similar geometries, this POD model was transferred to aluminum and copper as well. T2 - 7th European-American Workshop on Reliability of NDT CY - Potsdam, Germany DA - 05.09.2017 KW - NDT KW - Active thermography KW - POD model KW - Standardization PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/41882 AN - OPUS4-41882 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany