Signal phase indication of flaw depth by a lift-off noise free eddy current probe

The authors have developed a new eddy current probe named 'Θ probe' that generates no lift-off noise in principle and provides phase information on surface flaw depth. The signal phase of the probe indicates the depth of flaws without much influence from the length and width, although the signal amplitude changes a great deal. The authors expect that the new probe makes eddy current testing more quantitative in flaw depth evaluation than the conventional probes