Patent ID: 7750626

Claim:
An eddy current detection method for detecting discontinuities in an electrically conductive sample, comprising the steps of: a) providing sinusoidal excitation of the sample at a single frequency and measuring the response only at a single frequency as a function of time at one location, b) repeating the measuring step at least one more time at the same location for a different lift-off value, c) combining the responses to the measuring steps to determine a lift-off point of intersection (LOI) time point and a LOI response magnitude, d) performing at least one measurement of a magnetic response according to a) at another location on the sample without regard to lift-off to determine magnitude and phase of the response at a single frequency, and e) determining magnetic response magnitude at the LOI time point at the said another location, whereby variation in the response magnitude at the LOI time point is used to indicate defects.