Extremely low frequency electric and magnetic field strengths of 400 kV transmission lines and 400kV sub-stations

Electromagnetic wave consists of an electric field and a magnetic field at right angles to each other and to the direction of the motion of the wave. Frequency and wavelength characterize an electromagnetic field. In an electromagnetic wave, these two characteristics are directly related to each other: the higher the frequency the shorter the wavelength. ELF fields generally have frequencies up to 300 Hz. Other technologies produce intermediate frequency (IF) fields with frequencies from 300 Hz to 10 MHz and radiofrequency (RF) fields with frequencies of 10 MHz to 300 GHz. The effects of electromagnetic fields on the human body depend not only on their field level but on their frequency and energy. These fields are required to be limited to the prescribed values in the respective frequency ranges in order to avoid the effects such as heating and electric shock.