DGS diagrams and frequency response curves for a flat-bottom hole: A model-based approach

Abstract Recently, we have developed analytical scattering models for predicting the pulse-echo response of a flat-bottom hole in both contact and immersion testing. Here, we present the results of a series of experimental validations of the immersion case model. It is shown that the model can be used to develop distance-gain-size (DGS) curves and frequency response curves that compare favorably with experiments even in the very near field of the transducer. In fact, the model is shown to reproduce the entire scattered waveform from the hole quite accurately. The quality of these results suggest that the model can serve as an important new theoretical reference standard for a variety of ultrasonic calibration and sizing applications.