Digital eddy current apparatus for sensing and analyzing metallurgical characteristics of an electrically conductive material

A digital eddy current apparatus for sensing and analzying metallurgical characteristics of an electrically conductive material comprising:

• a. driving means supplying a square wave which is used as a reference;
• b. a resonating means coupled to the driving means, the resonating means having a sensing element with an impedance which varies depending upon an eddy current characteristic of the electricity conductive material, the resonating means changes the square wave to a sinusoidal waveform which is a function of the impedance of the sensing element;
• c. converting means coupled to the resonating means and converting the sinusoidal waveform produced by the resonating means into a rectangular pulse output, which pulse, when the resonating means is at a resonance condition, when referenced to the square wave pulse would be positioned in the center of one-half of the square wave, when the resonating means is magnetically coupled to the conductive material, the amplitude and phase of the sinusoidal waveform will be affected by the material characteristics, and the width and phase of the rectangular pulse will also be affected, the width of the rectangular pulse is a direct function of the amplitude of the sinusoidal waveform, movement of the rectangular pulse from its referenced position in the center of one-half of the square wave is a function of phase shift of the sinusoidal waveform;
• and
• d. means for monitoring the width and position of the rectangular pulse with respect to the reference square wave as a direct function of the electrically conductive material's metallurgical characteristics.