Patent ID: 8623197

Claim:
A method of evaluating an overcoat on a workpiece, the workpiece having the overcoat prior to the method of evaluating the overcoat being performed, the method of evaluating the overcoat comprising: submerging the workpiece having the overcoat in an electrochemical cell comprising a corrosive fluid; establishing a circuit path in the electrochemical cell using the workpiece as a working electrode and a reference electrode disposed in the corrosive fluid; applying an excitation signal at one or more frequencies to the circuit path; measuring a modulus of impedance value for one or more frequencies within a range of 1 Hz to 10 Hz at one or more time points; and dividing the measured modulus of impedance value by a high frequency modulus of impedance value measured at a frequency above 10 Hz to generate a normalized modulus of impedance value.