•3 Hz to 30 Hz
= ELF* (100 Mm – 10 Mm)
•30 Hz to 300 Hz
= SLF (10 Mm – 1 Mm)
•300 Hz to 3 kHz
= ULF (1 Mm – 100 km)
•3 kHz to 30 kHz
= VLF (100 km – 10 km)
•30 kHz to 300 kHz = LF
(10 km – 1 km)
•*Popular misuse calls anything from
about 3 Hz to 3 kHz ELF