The trifield EMF meter is the standard tool employed by paranormal investigators. This analogue Extended Range model is highly sensitive and can measure the amplitude (but not the frequency) of electric fields, magnetic fields and microwave radiation.

It is thought that ghosts cause Electro-Magnetic effects, so a high or fluctuating reading may, in conjnction with other forms of physical evidence such as photos, sound recordings or temperature fluctuations, indicate spirit activity. Well... at least, the meter can be used to map existing EM fields in a location, and high strength fields may be the cause of various anomalous effects.

The 0-3 Milligauss scale of this meter can register the EM field of a human or an animal as small as a cat. The main thing when operating an EMF meter, though, is to not wave it about. When you move the detector through a field (such as Earth's magnetic field), it will register a fluctuation. You can only tell if the EM field is itself fluctuating when the meter is held still.

Contrary to a theory that seems to have spread, there is absolutely no significance in the reading level of 7 milligauss! That particular number on the scale definitely does not indicate 'spiritual activity' any more or less than any other reading.

However these and similar devices are marketed nowdays, an EMF meter is not a Ghost Meter! The meters are factory-set to work in a certain way, and are frequency-weighted in their response. They were mainly used by the health-conscious to detect EMFs in the home, with the idea of avoiding lengthy exposure (and fair enough).

OK, so you can't call yourself a Ghost Hunter without one, but there is really no hard evidence to suggest that an apparition would be detectable using one of these meters. They do, however, allow the investigator to map natural and man-made fields on a site, and also to detect high-strength fields that may have an effect on human wellbeing and perception. Old or faulty house wiring can also cause strong EM fields which can be a health hazard (as well as burning your house down!).

www.trifield.com - Alpha Labs Inc. - suppliers of Trifield meters and other great equipment.
More info on the Trifield EMF meter, from Alpha Labs Inc.

Articles on the effects of EMFs on human health can be found here and here. Also see Dirty Electricity.

Need Electronics in Napier are one NZ retailer selling a very good digital EMF meter at a competitive price. If you can't justify the expense of an EMF meter, a regular old magnetic compass will tell you if there is a fluctuating or moving magnetic field present! Try it. Either way, there should always be a compass in any investigator's kit.

There is a great, if sceptical, article on the use of EMF meters, on the ASSAP site.

Trifield meter detecting the electric field around live household wiring.