In order tounder stand the relationship between the eddy current inter action and the magnetization of the sample,the tangential magneticfield images are discussed,which are in relationship to the distribution of the eddy current [9]. Fig. 6 shows the time sequential tangential magnetic field images of the square plate samples based upon the time of the applied magnetic field phase in increments of p/4. The measured frequencie swere 50Hz and 1kHz.The circular patterns of the tangential magnetic
field images were typically according to the eddy current