Optimal frequency combination estimation for accurate ultrasound non-destructive testing

A non-destructive testing system requires multiple system configuration parameters during the operation process. For a given transducer, scanning frequency and number of measurements for averaging are just among those parameters. This work tests the central limit theorem to optimally set these parameters. The authors have designed a compact ultrasound computer tomography scanner from scratch just to test this criterion. It is shown that optimal frequency value changes with respect to the scanning angle for an object with a heterogeneous inner profile. The proposed criterion helps to estimate the multi-spectral combination before the recovery stage minimum error. Possible industrial applications of such a system are 2D/3D multiphase flow profile recovery or crack detection in the composite matter, non-invasively.