Design of Reflection Type Pulsed Eddy Current Nondestructive Testing

Reflection type shielded send-receive probe is designed for accurate measurement of specimen thickness by pulsed eddy current testing and when evaluating material conductivity, effects of pulse width on the signal are investigated. Results show that the best sensitivity to thickness is achieved when ferrite shields for both coils are used and when the exciter coil is located inside the sensor coil. Pulse width study suggests that the shorter pulse width is desired if the peak amplitude is used to evaluate the material conductivity, while the longer pulse width is needed if the peak time is used for the same purpose.