Extremely low frequency (ELF) fields (>0 to 300 Hz) are one kind ofelectromagnetic fields, which are common used in people?s daily life.

• 极低频电磁场（extremely low frequency electromagnetic fields，ELF-EMF）是指频率在0-300Hz之间的电磁场，是与人们日常生活关系最为密切的电磁场之一。