EMF detector Range? (scifi story)?

Question

Could someone please explain the range a common EMF detector has?

I'm not sure I understand the science of it, but I need to know three things:

- what is a normal EMF ?

- what is the range of an EMF detector?

- what levels (obviously the high ones) might spark the curiosity of a ghost hunter.

Thanks :)

Answer 1

Electro Motive Force is measured in Volts, and measured by voltmeters.  Normally the voltmeter must be connected to the voltage source it is to measure (like a battery, power supply...).

Measuring the voltage (EMF) of a static electric field is difficult because most voltmeters draw a little current from the EMF source being measured and this reduces the measured voltage.  

Now, you must be talking about something else that likely does not belong in the field of science.  Is there a sci-fi category?  It would be a better place for this question if I understand what you are trying to ask about.

Answer 2

EMF= Electro MAGNETIC field?

(If so it certainly within the Field of Science!

"normal EMF" would be the background magnetism of the Earth.

Think ghost hunters are more interested in "unusual" patterns of EMF,but don't know that much about what triggers their interest

You may find it worthwhile to contact people involved in the so called Earth Mysteries. While clearly many are "nuts" there are some who take accurate observations/scientific measurements seriously. They should be able to provide you with some real data on sites which many have found "spooky" which could even give you some ideas for story lines.

I have read that the Dragon Project (noted for trying this approach without necessarily considering any implications)  found that the points a dowser pointed out on a standing stone, seemed to correlate to the EMF field around the stone. (I haven't checked wether the result were genuine or not. It doesn't count for much  but I have several trusted friends who knew the researchers/took part, and they say the results are genuine)

(yahoo answers isn't letting me post links, will try again latter!)

Answer 3

Electro Magnetic Field detector. they come in a variety of sensitivity ranges, just like metal detectors. 100,000 HRZ is a good sensitivity range to start with for entity detection, but those with lower freq. ranges as baselines will work well too. The higher it goes, the more likely you are to start picking up the earths magnetic field. Normal EMF..it all depends on what you are looking for! as far as range is concerned, the closer you get the better off you are.