MULTIPLE HELICAL COILS, TRANSMISSION EMAT SYSTEM AND RECEIVING EMAT SYSTEM USING SAME, AND TRANSMITTING/RECEIVING EMAT SYSTEM

摘要

The present invention provides a multi-helical coil which is formed by winding the conducting wire in the helical type and formed by serially connecting m helical coils having both terminals corresponding to the start and the end of the conducting wire, and which has one terminal of a first helical coil and the other terminal of an m-th helical coil as both final terminals among the m helical coils. According to the provided multi-helical coil, unlike a conventional meander line coil, the number of coil legs and the wound number thereof can be variously changed, and thus the design and the use of an optimal coil for the EMAT application are possible and the ultrasonic transmitting/receiving efficiency can be improved. In addition, it is possible to implement a transmission EMAT system, a receiving EMAT system, and a transmitting/receiving EMAT system which have superior ultrasonic transmitting/receiving efficiency due to the employment of the multi-helical coil.