Equipment:

Equipment that is known to be used for paranormal investigations and what its used for.

EMF meters
An EMF meter is an instrument that reads the fluctuation in electromagnetic fields. You should always take preliminary EMF readings at various places throughout the site. The locations of power lines, appliances and other sources of electromagnetic fields are also noted. Most normal readings are in the range of 9.0 - 30.0 on the EMF meter. These are typical EMF readings in a home. Anything that registers in the 2.0 to the 7.0 ranges and cannot be traced to a source is attributed to spirit activity. An example of a source would be a computer monitor. The closer you get to a natural source the higher the reading. A natural source should always appear in the same place and will not disappear. You should discard these readings. When you get a short EMF reading in the 2.0 – 7.0 range which you do not get it again in the same location and you do not find a natural EMF source then you have a positive EMF reading. It is scientifically impossible for low level and moving electromagnetic fields to occur naturally, but yet we find these fields in areas where there is spirit activity reported.
K2 If you watch Ghost Hunter they will use this meter to have the Spirit affect the meter by talking to it. There show has brought some surprising results.
Thermometers
IR thermometers capture the invisible infrared energy naturally emitted from all objects. Infrared radiation is part of the electromagnetic spectrum which includes radio waves, microwaves, visible light, ultraviolet, gamma, and X-rays. Any object warmer than absolute zero emits energy somewhere within that range.
IR thermometers range distance work differently for each model some will only read the temperature 5 feet in front of you and other will detect 20 feet. Know you meters before going into the field.
Digital Recorder
Used to recored Electronic Voice Phenomenon or EVP Ghost hunters or Paranormal Investigators now use Digital instead of analog to eliminate the table being the cause of the noise.
Video Cameras
Preferred method would be to use a DVR that can record a lot of hours to film a full investigation and beyond if able to leave the equipment over night or for days.
The Ghost Box
The “ghost box” as it has come to be known is an electronic system, or method of sprit communication, also known as instrumental trans-communication, or ITC. ITC is the use of electronic equipment to communicate across dimensions with spirits of the deceased, and other entities including audio, video, and digital equipment. It seems just about anything of a technological nature has been used, such FAX machines, telephones, TV’s, radios, computers, and printers, along with analog and digital voice recorders. Back in 2002 after 2 years of doing EVP work using various methods such as white noise, and the computer, I was using a program called EVPmaker, invented by the German researcher Stefan Bion. I kept getting messages relayed from spirits that could use the computer by spirits that seemingly could not use the computer. I was wondering what else I could use for spirit communication that all spirits could use, after about a week my “system” popped into my head fully formed, all I had to do was build it. The system consisted of using white noise, amplified, filtered, and rectified to produce a random voltage make voltage tunable radio receiver modules removed form older digital car stereos scan randomly across the AM, or FM broadcast bands. The randomly tuned radio modules provide a source of random audio which is sent to an enclosure that I called an echo box, for lack of a better name. The “idea” of the echo box was received by what I can only call telepathy, indicating to me there was at least some “outside” guidance in this system. The suggestion to use a box for the audio was received kind of like someone saying “look at that box” then having the idea to mount the speaker and mic inside it. It is my opinion that it is the random audio that allows the spirits, and other entities, to form their voices. White noise works because of this random principal, but random material that contains human speech frequencies, and fragments works much better, and more consistently. The random events, or audio, works I think because some kind of resonance on the quantum level is taking place, kind of like using the quantum soup of the universe as a carrier. I’m no physicist, so can only guess, and just barely describe how I think this equipment works.
--Frank Sumption
Build your own at http://www.keyportparanormal.com/images/theghostbox_1_.pdf