CPC G01N 29/2412 (2013.01) [G01N 29/043 (2013.01); G01N 2291/0258 (2013.01)] | 27 Claims |
1. An apparatus for detecting or measuring corrosion or erosion in an object, comprising:
an electromagnetic acoustic transducer (EMAT) having:
a ferromagnetic core;
a plurality of permanent magnets arranged peripherally around the ferromagnetic core and configured to produce a magnetic field through the ferromagnetic core; and
a coil configured between the ferromagnetic core and the object,
wherein the current in the coil is generated by a series of voltage pulses, and wherein a leading voltage pulse or a trailing voltage pulse in the series are shorter than the pulses in the middle of the series, and
wherein the current in the coil is about zero at an ending edge of the trailing voltage pulse.
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