Equipment

Because this is a theoretical field, there is no piece of equipment that should be considered ineffective or useless- given that you know how to use them properly and what you are looking for. Personally, just from experience, I've found most electronic devices (EMF, Geiger, etc) to be marginal at best. There is no substitute for a good camera (infared is always a plus) and good instinct. But there are ways that you can more effectively prove a haunting, through as I said, knowing the basics of your equipment.

Geiger Counters- These meters date as far back as the nuclear age in the 40's and 50's and are designed to detect high levels of radiation (X-Rays, Gamma, Cosmic, etc). The reason that these probably won't work in ghosthunting is just for that reason. What we look for comes from the lower end of the Electromagnetic spectrum- your radio waves, infared, even micro. So Geiger Counters can't detect the level of EM energy that is central to ghost hunting theory. If you do use one and get high readings, you probably won't care about what ghost you find, because you'll be dying of radiation poisoning. If you do use one, normal background should be 0-12 counts per minute (windows open) and as high as 22cpm closed.

EMF Detectors (Electromagnetic Field)- This device is the standard for ghost hunting. You see them all the time on TV and you may even use one yourself. People expect to see certain pieces of equipment being used on investigations and this is the golden one. This measures the ambient emf in a given area in milligauss (and some gauss), and unfortunately most can only measure in 2 dimensions, which means straight out in front of it (or wherever you point it). People get worked up when they get a reading and it starts to beep and flash but this is incorrect. When using these meters, if you get a consistent reading (that is to say if you have a constant reading of .7 milligauss) you're most likely reading an electronic device (hidden wires, computer, TV, etc). If these are even useful at all, one needs to look for just a little blip on the needle. If it reads zero, then suddenly spikes to .4 then goes back to zero, you may have found something. Generally, no presence will be able to "radiate" the power needed to make the meter beep and flash (but it does happen occasionally). But most importantly, if you have a constant reading, you have an electronic source. That is why preliminary investigations are crucial if you intend to use these. That way, you can find ahead of time where the electronic devices are that give you readings. When you do your investigation, if you get a reading where one shouldn't be, then you can assume something else and go from there.

Trifield Meter- This is the same thing as an EMF detector, the only difference being that a trifield meter can measure in three dimensions (hence trifield = three fields). Basically instead of pointing and reading straight ahead, the Trifield essentially projects a bubble out in front of it and will detect any EM radiation passing through it, from all sides. But it is more costly and more difficult to interpret unless you know something about physics or electricity.

Air-Ion Counter- If a compass is the poor-man's EMF detector, then the air-ion counter is the Bentley. This is a costly gadget but has more promising results than any other piece of equipment. Anything that emits an electromagnetic field creates ions, which are nothing more than charged atoms. This happens when the number of electrons do not equal the number of protons in the nucleus of an atom. So this meter will look for any change in the ambient charge of the air. Since we believe life is energy, it stands to reason that ghosts must be the residual energy of a person's life force, which means in order to stay active, it must absorb energy (electromagnetic) from somewhere. When you have a haunting, it takes alot of energy for a presence to be able to do things like talk or slam doors or anything, which means it is now giving off energy. When this energy is released, it displaces the ambient energy (atoms) and combines with other forms of energy. That is essentially how EMF works, but the air-ion counter will give a more thorough reading. Whereas EMF can only detect the strength of an EM field, air-ion can pinpoint the location and tell you the strength. Plus, this can read energy levels even lower than standard EMF.

It is important to note that analog meters are usually better than digital meters. This is because when you are looking for a ghost, it is easier to see the needle spike in a given area than it is to see numbers. Its a preference thing really, but you will have better, or at least more accurate results, if you use the analog versions.

Dowsing Rods- The practice of dowsing (as used today) began in 15th century Germany by Alchemists (known today simply as chemists) searching for certain metals. These rods are generally made of brass so that the earth's natural EM field will not affect the "reading" but instead will only detect EM fields radiated by an entity or other source. Sometimes, ghost hunters will attach a pendulum to the end of one and perform a poor man's EVP. The investigator will determine which direction means yes and which means no or other words and will speak to the pendulum. It is pretty much a clash of Ouija meets physics. I've never used them, but there is no real credible evidence to suggest they work.

Other items that are used:

1) Thermometer- IR versions, the ones that you can point and shoot to get a reading are preferred because its instant access. Many people have flawed thinking in that they believe that if a house is haunted, the temperature will drop when the presence is around. This is not always the case. One should always be aware of windows, doors, poorly insulated areas, etc so as to not confuse readings.

2) Camera- The basic essential. Needed for documentation purposes and for getting really kick ass shots. Sometimes you'll need to take 300 pictures before you get one good one. Digital cameras are best used, because you can instantly see in the viewfinder what the picture is. Especially ones with infared or night vision, its like shooting up an entity with steroids. When you project infared energy, you now have created an energy source for the being(s) so you're more likely to get a picture of something. Without one, you may get results too... you just never know. If you choose to use a 35mm film camera, be sure to use the fastest speed film possible, which is usually 800. When you get your pictures developed, be sure not to get 1 hour photo!! Send them to the lab and write on the package "Return As Is". Otherwise, the techs will filter out any anomolous things like orbs or otherwise and will give you the best picture possible- but not what you're looking for.

3) Recorders- When conducting EVP or even ambient sounds a good recorder should never be far away. Digital recorders work as well as standard cassette tapes. Both have their qualities and both have their flaws. Digital recorders sometimes can be TOO sensitive, whereas tapes (especially without a microphone) will record the device itself and all you'll hear is the tape spinning. Its up to you which you want to use, but be sure to use them properly.

4) Compass- Ghost hunting is not as high-tech as people would have you believe. A simple compass works in the same way as an EMF detector, and is useful for EVP too. Not only will it align itself to a magnetic field, but you can also ask an entity to move the needle in response to certain questions. "If you do not want us in the room, move the needle."

5) Flashlights, Radios, Batteries- You need to see and you need to communicate, especially if you get lost or in trouble. Batteries are important too, because they have energy inside them, and the entities will absorb the energy right out of them. Backups are good. The best batteries to use are rechargeable, but Duracell "Digital" works too. Not that I'm plugging a certain type, its just what I use because they work well.

6) Motion Detectors- An entity passing through the beam it projects sometimes sets off the alarm. It also keeps away pesky civilians who just have to see whats going on.

That about covers the the equipment aspect. Again, no piece of equipment should be considered useless, because since we don't really know what we're looking for, we don't know what will work. Through my experience, I have found what does and does not work for me, but that should not deter you from continuing. Ghost hunting is as much instinct as it is science.