One of the biggest questions about "ghost hunting" or paranormal investigation is about the usage of tools, typically the EMF detector (electromagnetic field detector, or magnetometer/gaussmeter).
When looking at EMF detectors there are basically two most popular and commonly used; the Trifield meter and the Trifield Natural meter. There are other models and types out there (gaussmeters) that are cheaper than the two Trifield meters, but with these tools you get what you pay for.
Before I go any farther I'll explain the models and basically what they do. A gaussmeter (or called a magnetometer) measures direct current magnetic fields. Basically detects and measures a magnetic field. The Trifield meter measures 3 fields (hence the "Tri") that are from technology; magnetic, Electric (both of these derive from faulty electric wiring, flourescent lights and other electrical items), and Radio/Microwave (cell phones, microwave ovens). The Trifield Natural meter meausres the same 3 fields but measures these electric fields that occur naturally, as “in nature”, and ignores man-made AC fields. This meter focuses on the Earth's magnetic field as well as natural electric fields generated by human beings (this meter can detect a person through a wall). The "sum" setting on both devices adds together the electric and magnetic and lets you know if either changes (but not which one specifically).
There are pros and cons for using each meter. The Trifield Meter can be used while walking around, the downside is that you must shut off all of the power in the area you are using the device for it to be truly effective. The Trifield Natural meter can be used with the power on, but due to the fact that it is measuring the magnetic field that it is in, the device is not effective if it is moving.
These devices should be used in magnetic mode for our purposes. The Natural meter is most tied to parapsychology (energy fields given off by people by PK/ESP) and detecting ghosts (energy use) though both are reliable for our purposes.
The most important thing about using these tools is knowing why or why not to use them. These tools are not ghost detecting devices, they measure the fields or energy that the apparition or haunting has affected. These devices are used to back up witness testimony or actual events, used by themselves do not offer any evidence to a paranormal event.
These devices can be seen or purchased from the following websites:
Alpha Lab Scientific Instruments
Edmond Scietific's Electromagnetic field detector
Paranormal Detection Equipment
Paranormal Investigator Outfitters
For more in-depth information on this topic and others on tools of the field, please visit Ghost Gadgets.com.
Brian D. Parsons
Director,
Ohio Paranormal Investigation Network