Abstract: An innovative multi-dimensional, low frequency, impedance measurement probe array, measurement system, and method are disclosed for detecting flaws in conductive articles. The device and method provide for contacting a conductive article with an multi-probe array of current and voltage probes, injecting current sequentially through a plurality of current probe pairs and measuring absolute or relative voltages with a plurality of voltage probes and voltage probe pairs across the surface of an article for each current flow condition. The device and method further provide for constructing a voltage profile across the surface of an article where disruptions in the voltage profile enable detection of the presence, location and orientation of flaws for flaw sizes as low as 20 um.

Abstract: A method and apparatus for encoding a sequence of 32 bit digital data words into a sequence of 33 bit code words in consonance with predetermined minimum zero run length (d) and predetermined maximum zero run length (k) for recording upon a magnetic medium within a magnetic recording channel is disclosed. The method comprises steps of dividing each data word into eight data nibbles, determining whether any data nibble contains all zeros. If no code violation, mapping the eight data nibbles to seven code nibbles and to four bits of a five bit code sub-word and setting a fifth control bit to one. If one or more code violations are present, embedding code violation locations within at least the five bit code sub-word and other code nibbles if necessary and remapping data nibbles ordinarily directed to the code sub-word and nibble locations to code locations otherwise containing the data nibbles determined to be code violations.