Analysis and Test of EM Shielding for Low-Frequency Magnetic Field

Electromagnetic shielding is the technique that reduces and prevents coupling of undesired radiated electromagnetic energy into equipment, so as to enable it to operate compatibly in its electromagnetic environment. Usually, the frequency considered for electromagnetic shielding design is above 10 kHz, but the lower frequency for some special demand is 50 Hz or even 0.01 Hz sometimes. This paper mainly studies the shielding design for low-frequency magnetic field, and the shielding effectiveness of single shielding and multimedia shielding are discussed separately. Moreover, the shielding effectiveness of a steel shielding enclosure and two different shielding doors for low-frequency magnetic fields in the near zone is measured.