Simulation and experimental study of multiple defect detection in billet from time-of-flight profile by transmission method with linear scanning

In this study, the validity of the detection of multiple defects in a billet by time-of-flight (TOF) profile and transmission method with linear scanning are evaluated through simulation and experimentation. Simulation results show that TOF measured using the transmission method has higher lateral resolution than using echoes from the defects. Although distinguishing each defect from the TOF profiles becomes difficult when defects are close together, the size of the defect should not be underestimated. As the TOF profiles are consistent between the simulation and experimental results, it is believed that the verification results of the TOF-linear method by simulation are valid.