IR cameras and lights are used because IR light (infrared) is invisible to the human eye, and IR cameras see a light spectrum that our eyes can't. As well, unlike conventional lighting, it will not disrupt the location being investigated, or tamper with our adjusted night visions. We can reduce the chance of false anomalies found in photography, or video, and increase the chances of capturing authentic results, as some spirits have generally been proven to be visible outside our visible spectrum that only these types of cameras/lights can pick up on.
IR thermometers are used for a similar reason to IR cameras, with the main exception being that IR thermometers pinpoint exact locations of temperature, and not just ambient temperature. This means that during an investigation (in the dark), we can be sure that the temperature reading we are taking is of an area of interest, and that spike or drop in temperature isn't coming from a heating duct, or a drafty window.
Motion detectors are used because they can pick up any motion that occurs in front of them, within a given distance. This means that even though we may not see anything while we are investigating, but perhaps we feel something, if there truly is anything paranormal moving around, the motion detector will detect it and turn on, whether or not it is visible to the naked eye.
Digital audio recorders are used to pickup any voices that may be inaudible to human ears. They allow us to ask questions, interrogate spirits, and then playback the audio to see whether or not we captured any responses we may not have heard in a frequency below our echoic capabilities.
EMF readers allow us to measure the electromagnetic field in an area, or around an object. It is believed that spirits use EMF's and electromagnetic energy to manifest, and any spike in an EMF reader can tell us whether we may or may not have anything paranormal on our hands. High EMF readings could indicate other factors, such as electronics, wiring, etc. High levels can reportedly result in headaches, wooziness, sickly feelings, or anxiety. As every object and person emits an EMF, however small or large, it may not be anything paranormal, but rather just environmental, which is why EMF readers are crucial to investigations.
The P-SB7 Spirit Box is a radio frequency scanner that sweeps through various FM/AM radio frequencies at a sweep rate of 100ms down to 350ms intervals. This piece of equipment works by scanning through the various radio wavelengths and white-noise, that spirits are said to be able to communicate within. Basically, the idea is that if one hears a sentence, or a distinctly worded response to one's questions, then you may have just captured evidence of the paranormal. The P-SB7 does not remain on a single wavelength long enough for any actual words to be picked up by radio broadcasts. Therefore, if one were to ask a question, and receive a complete response, in a continuous spread, it is believed that one may have just spoken with a spirit in real-time.
Walkie-Talkies* are simply used to keep in contact with respective team members, and can act as a safety mechanism, or means of communication between other parties involved.
EM Pumps are devices intended to generate small electromagnetic fields around themselves. This is used under the assumptive theory that spirits are attracted to electromagnetic energy, and use this energy to manifest. They are purported to increase the level of activity within a given area incrementally as more EM Pumps are placed.
The Microsoft Kinect Sensor allows us to utilize skeletal tracking and depth tracking, via infrared and other technologies, to gauge whether or not a potential spirit is manifesting, or moving around a physical space. If activity is captured in accordance with the Kinect Sensor, this would further validate any findings we may have, as well as potentially allow us to see, in real time, any movements a potentially manifesting spirit may be making in our environment, of which we are unable to see with the naked eye.
The iOvilusis an app designed by Digital Dowsing, the same company that made the original Ovilus device, which has now been discontinued. The reason it has, is because all the sensors that are found in modern day technology, such as a smartphone or even an iPod, can work just as well as buying a stand-alone device! The theory behind it is that a spirit can use the sensors in your phone, for example, to manipulate external environmental data, affecting the sensors, allowing a word from a word bank to be chosen and relayed back to the investigator. There is some fine tuning and tweaking to be had so as to mitigate false responses, and part of our job is to weed out what is random misfires, and what is pertinent, direct lines of communication to conversations or questions.
Word Banks - A combination of fragmented sounds, that hypothetically could be pieced together to form words. These sounds are randomized, and can be manipulated through sensors (depending on the device/app/etc) to theoretically allow a potential spirit to "select" the sounds they wish in order to form words/sentences and communicate in real-time.
* THE USE OF CELL PHONES IS PROHIBITED DURING INVESTIGATIONS AS THEY CAN TAMPER WITH DEVICES AND READINGS. ALL CELLULAR DEVICES USED BY INVESTIGATORS ARE (AT LEAST) PLACED ON AIRPLANE MODE PRIOR TO INVESTIGATION PROCEEDINGS.