Evanescent microwave sensor scanning for detection of sub-surface defects in wires

Abstract

Evanescent microwave probe (EMP) scanning is used to detect sub-surface defects in copper wire with high dielectric coatings. The primary interest is in winding wire used in the construction of high voltage motors, generators and transformer applications although this technique can be applied to other aspects of stress and flaw detection. Evanescent microwave probes have the unique ability to image subsurface features under poorly conducting or dielectric materials. This nondestructive evaluation technique will allow fast and highly accurate subsurface scans of armature or stator wire in inspecting for various surface anomalies.