Design and Implementation of a Remote Field eddy Current Sensor

Abstract

VII ABSTRACT: Non-destructive testing has a large number of techniques, with different characteristics, advantage and limitation a make the NDT a fertile field for scientific research. Pulsed remote field eddy current technique has utilized broadly in the detection of tubular structures because it proves good results with minimum requirements. a novel PRFEC sensor design is proposed with coaxial coils shape and simple signal processing circuits, this sensor moves by a CNC machine on X-Y and Z-axis in order to automate the inspection and enhance the stability of the sensor. A number of experiments with different values of lift-off, duty cycle, excitation amplitude, excitation frequency and with different defect depths have carried out. The results show a deep penetration depth up to 8mm with high sensitivity where it can differentiate between cracks with 1mm difference in-depth, the designed sensor proved a good detectability .