Experimental Validation of an Eddy Current Probe for Defect Detection in Thick Conducting Specimen

This paper presents numerical modeling and experimental measurements of eddy current (EC) probe for detecting subsurface defects in 10 mm to 15 mm thick conducting specimen. Measurements are presented for a pancake air core coil to detect subsurface defect in 10 mm thick aluminum slab. EC coil parameters namely inner radius(r(1)), and outer rradius(r(1)), and operating frequency (f); are optimized for deeper penetration in the conducting plate (35 MS/m) for a given coil height (h), and lift off distance (d). Preliminary simulation results are presented for a subsurface defect in 15 mm thick aluminium plate for the optimized EC coil parameters.