What is extremely low frequency emission?

The tone of lowest frequency is called the fundamental ; the others, overtones. The frequencies of the overtones may be whole multiples (e.g., 2, 3, 4, etc., of the fundamental frequency, in which case they…

The VLF band is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication . Since VLF waves can penetrate at least 40 meters (131 ft) into saltwater, they are used for military communication with submarines.

Very low frequency (VLF) is a radio frequency band in the range of 3 to 30 kHz with wavelengths from 10 to 100 km . It is also the name of the band designated by the International Telecommunication Union (ITU).

Extremely Low Frequency Emission Hazards: During the 1990s, most electromagnetic frequency (EMF) research focused on extremely low frequency (ELF) exposures stemming from conventional power sources, such as power lines, electrical substations, or home appliances .