The primary advantages and Disadvantages when compared to other NDT methods are:

When the magnetic flux passing through the area enclosed by the closed conductive loop changes, an induced current is generated in the loop. This phenomenon is called electromagnetic induction.

The test surface is cleaned to remove any dirt, paint, oil, grease or any loose scale that could either keep penetrant out of a defect, or cause irrelevant or false indications.

The skin effect induced by the eddy current is concentrated in the vicinity of the surface of the material near the excitation coil. The eddy current density decreases as the distance from the surface increases.

Dye Penetrant Inspection (DPI), also called Liquid Penetrant Inspection (LPI) or Penetrant Testing (PT)

Using the principle of electromagnetic induction, non-destructive evaluation of certain properties of conductive materials and their attack by measuring changes in induced eddy currents in the attack, or a non-destructive detection method for defects,