Study on Eddy Current Signals Measured Using Coil Sensor and PHR Sensors

We used coil sensor and PHR sensor in order to measure the amplitude and phase of eddy current signals induced by flaws. The amplitude and phase of eddy current signals were propositional to depth of flaws in both sensor. The phase of eddy current signals measured by PHR sensor were more larger than that measured by coil sensor. The benefits of tiny PHR sensor compared with coil sensor were high spatial resolution as well as very high flaw detection capability at low frequency.