LEAKAGE FIELD FLAW DETECTOR WITH CURRENT ENERGIZATION WITH MEANS TO CONTROL CURRENT ENERGIZATION BY PROBE SCAN

摘要

A nondestructive testing apparatus and method are disclosed herein for testing objects by measuring the stray magnetic flux field adjacent the surface thereof. The workpiece is magnetized by means of a pulsed electric current circulating therethrough during a portion of the test interval whereby the magnetizing is accomplished with a minimum amount of power. The amount of magnetizing power required is further reduced by recording the stray fields on a magnetic medium such as a flexible tape and subsequently scanning the tape with a suitable magnetic pickup probe.