Probability of detection analysis of round robin test results performed by flash thermography

Abstract

Within the scope of a standardisation research project, a flash thermography round robin test that evaluates reliability, comparability and efficiency of different testing situations was performed. Data recorded at metal test specimens with flat bottom holes (FBHs) were analysed by calculating the signal-to-noise ratio (SNR) of the defect signatures in the thermograms as well as in the phase images as a function of defect parameters. A new multi-parameter probability of detection (POD) model was developed, where an â versus a continuous signal analysis was based on the linear relationship between the SNR and a multi-parameter a. This linear relationship 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

Thermal imaging monitoring of local temperature of isolated and transplanted liver and kidneys as a way to diagnose real time transplantation in the clinic

“…The existing world experience of thermometry in medicine [1][2][3][4] at the first stage of the study, let us evaluate the temperature of the storage solution and transplants at different stages of the operation. It was found that the median temperature of the transplant is +5.4 °C in the storage solution of the generally recognized worldwide temperature.…”

Performance Assessment for a Guided Wave-Based SHM System Applied to a Stiffened Composite Structure

“…When considering the quality, capability and reliability of an SHM system, four fundamental influencing factors have been identified: algorithms, intrinsic factors, application factors and integration factors (see Table 1 ). Influencing factors have been widely studied in traditional NDE methods [ 33 , 34 , 35 , 36 ]. Although some of the factors apply to SHM methods as well, there are some differences to be considered.…”

Analysing the probability of detection of shallow spherical defects by means of Active Thermography

“…The PoD is a quantitative measure of the capability of a non-destructive technique or methodology and allows the determination of the defect detection probability as a function of a parameter describing the defect geometry (ASME 3023-15) [2]- [3], [19]- [21]. This methodology should produce output that can be summarized within a representative quantitative signal, 'â', or a binary response, hit/miss.…”

“…Up to now, there have been several studies concerning the determination of the PoD of standard and more conventional non-destructive methods like ultrasonics, eddy current, and radiography [22]- [23]. Some works also regard the application of active thermography with this purpose, in particular, lock-in and pulsed techniques, but considering in most cases FBHs defects [2]- [3]. In order to determine the PoD curve, a relationship between the variable that describes the defect and the one that characterizes the signal contrast is necessary [2]- [3], [19]- [21].…”

“…Some works also regard the application of active thermography with this purpose, in particular, lock-in and pulsed techniques, but considering in most cases FBHs defects [2]- [3]. In order to determine the PoD curve, a relationship between the variable that describes the defect and the one that characterizes the signal contrast is necessary [2]- [3], [19]- [21]. In this work, to obtain the PoD curves, a series of specimens in AISI 316L, for a total of twelve, were produced by means of L-PBF technology.…”