Apparatus and method for detecting defect using multiple phase selectable pulsed eddy current

A method for detecting defect using multiple phase selectable pulsed eddy current (PEC), the method comprising:

• an irradiation step (S10) of irradiating a PEC signal to an object (10) by using a PEC irradiation unit (20);
• a time-sharing step (S20) of dividing the PEC signal measured in the PEC irradiation unit (20) in time sharing way by using a program stored in a measurement unit (30) connected to the PEC irradiation unit (20);
• a selection step (S30) of automatically selecting two measurement values having high output values among the PEC signal divided in time sharing way in the measurement unit (30), by using the program stored in the measurement unit (30);
• a result deduction step (S40) of substituting the two measurement values selected at the selection step (S30) for an X-axis value and a Y-axis value of a graph, respectively, and deducing a resultant value of a point at which the two measurement values meet each other;
• a display step (S50) of displaying the resultant value deduced at the result deduction step (S40) on a display unit (40);
• and
• a defect determination step (S60) of moving the PEC irradiation unit (20) for measurement, displaying the measurement values of a number of points measured by the measurement unit (30) by repeating the irradiation step (S10), the time-sharing step (S20), the selection step (S30), the result deduction step (S40) and the display step (S50) to display each of the points on the graph shown on a screen of the display unit (40), comparing the resultant values in the graph changed from a zero (‘0’) point of the graph, detecting a position corresponding to a defect of the object (10) and determining as to presence of a defect of the object (10).