| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and apparatus for digital measurement of conducting an eddy current test of a test object. SOLUTION: A coil in a probe is driven with a generated digital drive signal converted to an analog drive signal, and then the probe is placed in proximity to the test object. An electromagnetic field, generated by the test object, for generating an analog return signal is received and converted to a digital return signal. The amplitude of the digital return signal is measured, and then a phase shift of the digital return signal compared to the digital drive signal is measured, followed by determining a phase shift angle of the digital return signal based on the phase shift, determining the quadrature components of the digital return signal based on the amplitude of the digital return signal and the phase shift angle, and analyzing the quadrature components of the digital return signal to determine a material characteristic of the test object. COPYRIGHT: (C)2009,JPO&INPIT
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