Method and apparatus for a multi-channel multi-frequency data acquisition system for nondestructive eddy current inspection testing

An eddy current inspection apparatus for detecting flaws in a conductive surface comprising:

• a plurality of spatially correlated eddy current probes comprising at least one drive element in cooperation with a plurality of sense elements operating in reflectance mode;
• means for driving select probe drive elements with a plurality of select frequencies;
• means for automatically scanning in a vicinity of the surface to synchronously acquire discrete scan responsive measurement signals from each probe sense element of the plurality;
• means for responsively multiplexing measurement signals onto a predetermined number of independent data channels in order to collect a corresponding plurality of measurement signals for parallel processing;
• means for demodulating each signal of the plurality against a reference frequency in order to obtain a corresponding pair of basis components for image processing;
• means for converting each component pair into digital format;
• automated means for storing the digital components;
• and
• means for automated parallel image processing of the digital components.