Ion Counters / Ion meters or to more correctly negative ion detectors are used to detect the ionisation of gases in the air. To put this more into layman's terms it is the level of electrical charge in the particles in the air.

While there are means to measure temperature, humidity and electro magnetic energy (EMF) at haunted locations attention has for a while now been turned to the measurement of Negative ion’s. These occur naturally, but are thought my many in the paranormal field to represent the energy source behind paranormal activity.

It is accepted in paranormal circles that most paranormal activity occurs where there is a ready supply of energy, what kind is the most debateable point, but negatively charged Ions are well up in the ratings. It follows that if you can find areas with high levels of charge you "could" be looking at an area that "may" have the capability to be active, more so if the area has a history of activity.

Once you have found your charged area, set the meter up and watch for variations in ionisation levels. A note of caution this equipment is very sensitive and a human passing close by can send the meter to the end stops, the is also true for most of equipment investigators use.

You may notice the levels going up or down. Down "may" indicate that something is drawing on the energy, or it may just be that what was causing the energy in the first place has stooped doing it. Up may indicate that something was drawing energy and has stopped doing it. Once again caution, this may just be the ionisation source giving off a bit more energy.

Ionisation can occur from many household devices, TV's, Ionisers, Electric Motors, Night Vision  Video Cameras, Camera Flash Units in fact anything where there is a magnetic flux and high voltages. Mains voltages are obvious, TV's, Video cameras and flash guns less so. Would you believe that most televisions generate voltages of 35,000 Volts to power their CRT tubes, a flash gun less, but typically around 2,500 - 10,000 volts are used.

It must also be remembered that negatively charged ion fields can be created by natural sources, for example lightning strikes and strong winds causing static charges as well as by artificial sources.