Definition - What does Electromagnetic Field mean?
An electromagnetic field is an invisible electric and magnetic field of force that usually occurs due to natural sources such as the Earth's magnetic field, but can also be caused by human activities through the use of electricity. An electromagnetic field may accelerate or decelerate the rate of corrosion.
Corrosionpedia explains Electromagnetic Field
Electromagnetic fields are currents created in high voltage electrical power lines at such a high level as to induce electromotive forces into said power lines. Although invisible to the naked eye, they can be found everywhere.
Electromagnetic fields are usually generated by the presence of an alternating current (AC) in electrical conductors. Alternating currents can range from one cycle per thousands of years to quadrillions of cycles per second.
The standard unit of electromagnetic field measurement is the Hertz (Hz). Alternatively, larger derivative units are often used, such as kilohertz (1,000 Hz), megahertz (1,000 kHz) and gigahertz (1,000 MHz).