What Is EMF?

An AC electromagnetic field, also known as EMF or EM field, is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The field can be viewed as the combination of an AC electric field and an AC magnetic field. Since it is AC by definition, it continually changes polarity from positive to negative.

What Are AC Electric Fields?

AC Electric Fields (E-Fields) are produced by the presence of electricity. Their strength is determined by voltage; the higher the voltage, the stronger the field. AC Electric Fields are generated by live electrical wires and generally travel 6-8 feet from the source, but in some cases further. An electric field will exist even when a device is not in use (turned off). In other words, these sources produce a continual emission. AC Electric Fields have a natural attraction to ground and the human body. They are considered low frequency electromagnetic radiation. (5 Hz – 400,000 Hz). They can be measured with an AC Electric Field meter and the unit of measurement is Volt per meter V/m.

What Are AC Magnetic Fields?

Living spaces contain dozens of electronic devices and electrical appliances. When this equipment is active or turned on, a flow of electrical current begins. This flow of electricity through the equipment and wiring is responsible for creating AC Magnetic Fields (B-Fields). The intensity or strength of the magnetic field is directly related to the power consumption of the device. A more powerful device will produce a higher magnetic field. These fields usually remain close to their source (2-3 feet), but can travel several hundred feet; an example is in the case of high voltage power lines. AC Magnetic Fields are considered low frequency electromagnetic radiation. (5 Hz – 400,000 Hz). They can be measured with a tesla meter in nanoTesla (nT) or with a gauss meter in milliGauss mG. Note: An AC Magnetic Field is typically what people refer to as EMF but this is an inaccurate statement.