Evaluation of Square Type Electromagnetic Field Screen Implementation on Interference Effects in Magnetic Induction Tomography Modality

摘要

This paper discusses and evaluates the implementation of square type electromagnetic screen on the excitation coil of Magnetic induction tomography (MIT) through real experiment. By using electromagnetic screen, interference phenomena due to scattered primary field can be reduced, hence reducing the sources of errors in the measurement data. In this experiment, two types of screen with different thickness of 2 mm and 25 mm had been evaluated. The measurements have shown that relative to without screen, 2 mm thickness screen reduces the field at about 84.31% at the back area while increased the field strength up to 19.45% in the front region. Excitation screen with 25 mm thickness provides better reduction of 98.43% at the back, however there is also reduction at about 9.82% of the field strength at the front region. The result from this experiment provides valuable information on the specification needed when applying electromagnetic screen to the individual excitation coil in the MIT system.