Patent ID: 6407546
Filing Date: 2002-06-18
Classification: G01B

Abstract:
A method for identifying a thickness of an inspection sample, said method comprising:(a) generating a natural intercepting curve based on resistance and reactance measurements of at least two data points; (b) obtaining a plurality of corresponding resistance and reactance measurements of a location on said inspection sample with an eddy current sensor, wherein said eddy current sensor makes a first measurement at a first distance from said inspection sample, and makes each of the remaining plurality of measurements at a distance that is incrementally further away from said inspection sample; (c) generating an inspection sample curve based on said plurality of corresponding resistance and reactance measurements obtained from said inspection sample; (d) determining an intersection point between said natural intercepting curve and said inspection sample curve; (e) calculating a vector impedance for each of said at least two data points and for said intersection point, to identify a closest two of said at least two data points that said intersection point is positioned; and (f) identifying said thickness of said location by performing an interpolation between said closest two of said at least two data points.