For starters, any electrical energy travelling through wires, radio signals, appliances, and televisions all produce Electromagnetic fields. EMF always consists of both an electrical field as well as a magnetic field. They occur in a very wide range of different frequencies which makes up the total electromagnetic spectrum.
In the Electromagnetic spectrum it moves from low to high electricity or (radiation). Low electromagnetic fields are often man-made such as electrical wiring and basic electricity. The high end of the spectrum deals with cosmic radiation. The range that we call the EMF field falls within these lower frequencies of the spectrum.
As stated, electricity is the most common form of EMF. They start in factory generators and move along their wires eventually making it inside your home in the form of wiring outlets. Everything that you plug into the wall has its own EMF. This includes everything from your television to your hair dryer. In addition, EMF is also generated by cellular phones, satellite, microave, and radio. They are generated by cars, trucks, planes and anything else electrical.
With this in mind we can assume the amount of EMF in a busy office setting. EMF can be very high and/or abundant in these areas and you need to be away of this when scanning.
EMF has never been proven good to people. It has always been a growing concern and several and starting to take note of these fields around where we live and work. The entire effects are not know but there has been studies linking EMF to cancer as well as other biological and chemical reactions in the body. These health effects are in no way achieved overnight but studies suggest very long term effects..
Now that we have a vague idea what EMF is we can use our meters. Below are a few simple hints that has helped me get good results and weed out the false ones.
1. Nearly all ghost hunters agree that spirits (ghosts) interfere with the electromagnetic field and when you approach a ghost you will see results on your meter. After reading the above you must always be careful that there are many different things that can produce results. In other words, when you see your meter spike, don't always assume that it is a ghost. (It could even be coming from another piece of equipment you are carrying)
2. When you walk the area hold the meter out and do a slow sweeping motion including up and down. Never whip the meter around and move it fast. On certain models this can (and usually does) produce a false reading. There are models that have been made to ignore power sources but that is personal choice.
3. As you continue your sweeping move from room to room making note of your meter and it's readings. If you are absolutely that nothing is interfering with the meter and it spikes all of a sudden, it is possible that you have detected some sort of paranormal energy. At this time, make notes, snap a few pictures and remember the location. You may even be able to (follow) the signal if it is strong. EMF has been know to move around thus follow it with your meter.
4. Before attending any serious ghost hunt, always be familiar with your equipment 100%! This means to test the meter completely, move it around known power sources and know how it reacts. Turn appliances on and off and check again. In other words you should know your meter well, know how it handles, and know how it reacts to everything. When something paranormal does interfere you will be much more educated to recognize it.
5. Check everything including closets, on top of beds, around door frames, in the shower, crawl spaces, and garage doors. The idea is to leave no area uncovered. Make sure you signal your camerman to snap pictures when activity is detected and make notes as to the reading and your location. Usually when EMF is detected you will want to come back to the same area later and recheck again. If you recheck an area 3-5 times and still get spikes there is a good chance that it is an electrical source and not a ghost, but that is for you to determine. I have even heard that pipes can trigger EMF meters. Always be aware of your surroundings.
6. One last point and I do this with my camera as well. As you are walking through an area, every so often turn around and sweep behind you. The theory behind this is that ghosts can follow us. If you do this with yourt camera as well you may notice some nice activity..
Good Luck