EMF Meter

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EMF meter, Electromagnetic field meter, (sometimes referred to as an EMF Detector) is a scientific instrument for measuring electromagnetic radiation.

One example of an EMF meter

There are many different types of EMF meter, but the two largest categories are single axis and tri-axis. Single axis meters are cheaper than a tri-axis meters, but take longer to complete a survey because the meter only measures one dimension of the field. Single axis instruments have to be tilted and turned on all three axes to obtain a full measurement. A tri-axis meter measures all three axes simultaneously, but these models tend to be more expensive.

Most meters measure the electromagnetic radiation flux density, which is the amplitude of any emitted radiation. Other meters measure the change in an electromagnetic field over time.

Electromagnetic fields can be either AC (Alternating current) or DC (Direct current). An EMF meter can measure AC electromagnetic fields, which are usually emitted from man-made sources such as electrical wiring, while Gauss meters or magnetometers measure DC fields, which occur naturally in the earth’s geomagnetic field and are emitted from other sources where direct current is present.

EMF meters usually measure radiation in milligauss. In absence of a moving magnetic field, an ideal meter will read 0 milligauss. Industrial EMF meters will often read 2-3 milligauss when placed in an open field devoid of emitters such as power lines (either overhead or buried).

The majority of EMF meters available are calibrated to measure electromagnetic radiation, which is alternating at 50/60Hz (the frequency of US and European mains electricity)This is because in recent years people have become concerned about the long-term health effects of exposure to high levels of radiation emitted from some electrical appliances.

There are other meters which can measure field alternating at as little as 20 Hz However these tend to be much more expensive and are only used to specific research.

[edit] Paranormal Investigation

The same device is also used widely by ghost hunting groups. Critics of paranormal investigation contend that EMF meters are misused to indicate the presence of an apparation, as there is no proof that alleged spiritual beings emit an electromagnetic field.