EMF (Electromagnetic Field) meter
CORPS uses a variety of EMF meters from different manufactures. EMF meters detect and report the intesity of Electromagnetic fields. Electromagnetic fiields are physical fields produced by electrically charged objects. It is thought that paranormal phenomena give off higher than normal electromagnetic fields and thus allow an EMF meter to detect them from normal EMF levels.
EMF meters really only report relevant data when a baseline reading is taken from the entire area being investigated. For example, if a baseline reading from the area is found to be between 0.1 and 0.4 and then during the process of an investigation the meter finds EMFs above the baseline, it may indicate the presence of a paranormal entity however, this data alone cannot really be used as evidence and should only be used to help find areas to be investigated further with a digital voice recorder, camcorder or digital camera.
EMF meters range in price between $40 and $200 depending on their sensativity and construction. They can be obtained through eBay or other web-based electronics stores. CORPS prefers EMF meters with a digital display compared to a needle type display for more accurate readings.