Patent ID: 7206706

Claim:
A method for inspecting a part, the method comprising: applying a plurality of multifrequency excitation signals to a probe to generate a plurality of multifrequency response signals for the part being inspected; and performing a multifrequency phase analysis on the multifrequency response signals, wherein the probe is an eddy current probe, wherein the applying step induces a plurality of eddy currents in the part, wherein the multifrequency response signals are generated by the eddy currents induced in the part with the eddy current probe, and wherein performing the multifrequency phase analysis comprises: identifying a reference dataset, wherein the reference dataset comprises at least two frequency response signals, and wherein the at least two frequency response signals comprise distinct frequency ranges; mixing the at least two frequency response signals to determine a plurality of processing parameters; and applying the processing parameters to a multifrequency response signal dataset to generate a noise-filtered dataset, the method further comprising: using the multifrequency phase analysis to inspect a subsurface of the part.