I often see, on social media, paranormal investigators and various groups proudly displaying their equipment: piles of cameras, digital recorders, REM pods, various EMF meters, and a wide assortment of other communication-related gadgets. Thousands of dollars' worth of equipment is quite the commitment to searching out answers from the great beyond, and I tip my hat to them, because while on an investigation one never knows exactly what piece of equipment you are going to need. What I rarely see in these grand displays is the equipment that could prove that the reputed haunting has nothing to do with ghosts. As investigators of the paranormal we have a responsibility to be sure that if we are going to claim legitimate paranormal activity we first must rule out anything of a natural occurring situation.

Part of my kit is what a home inspector would carry; this equipment can add up in cost, but it allows me to collect important data and rule out things that are not paranormal. It also gives be a better, more well-rounded look at the location I will be investigating.

We all have EMF meters, which is great, since these can tell us about electromagnetic frequencies in the building and we can add them to our baselines. Standard EMF meters can discover many man-made sources like appliances, faulty wiring, and wireless devices at frequencies around 50/60 Hz, as well as radio frequencies. I also use a natural EMF meter that will detect weak unpolarized, unmodulated frequencies associated with atmospheric electricity and or static fields.

I also look for mold and I run a complete examination of the air quality, allowing me to note any concentrations of carbon monoxide and carbon dioxide including radon.

By using a frequency counter, I can look for odd frequencies within the house and determine if infrasound (frequencies below 20 Hz) could be a problem.

I like to use a handheld anemometer; this little device will allow me to discover air flow and flow around windows and doors, which can be important if your client has reported temperature changes and odd breezes (and may also explain why some light objects move).

Recording both ambient light and ultraviolet light can be important, as well. Baselines should be taken at various time during the day and evening. Ghosts can manipulate light, including ultraviolet frequencies. Plus, if you are using full spectrum cameras, you should be aware of these other sources of light.

I always check ambient sound within the building and compare it the exterior; it gives me a better idea of what sounds the house makes naturally and how well the house muffles exterior sounds inside.

The last test I run is background radiation, just to be thorough.

Establishing these baselines is definitely a lot more work; however, I find it provides a great deal of important data and allows for the investigator to understand better the property being investigated. This also helps with the investigation when the results are scrutinized by skeptical or scientific communities, as you can demonstrate answers to their standard question before they even get a chance to ask them.

Remember: Sir Arthur Conan Doyle wrote in The Case-Book of Sherlock Holmes: "When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth."