Сalculation and design of EMAT for ultra-sonic nondestructive testing

The article focuses on the design of electromagnetic acoustic transducer (EMAT) for ultrasonic nondestructive testing of metal products. Some theoretical calculations of a number of the inverter parameters have been carried out; the influence of the screening, the transducer sensitivity dependence on the gap between EMAT and the testing surface have been considered. The article also includes theoretical calculations of magnetic field distribution and parameters of EMAT magnetic system. The measurement results of radiation patterns of direct and oblique EMAT for a number of wave types at different frequencies are given. The experimental and theoretical data were compared. The EMAT radiation directivity dependence on the number and the relative positions of the conductors carrying a current is also presented. The results of those studies can be used in optimizing the EMAT parameters in their design.