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 Posted: Jun 5th, 2014 01:12 PM
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sparks
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Yes, a coil connected to a dc voltmeter will indicate a magnetic field IF there is relative movement between the two (Faraday's Law). The sensitivity is however quite poor. Can be improved by adding a dc coupled high gain amplifier in. This is the basis of what have been called UFO detectors.

Commercial emf detector units usually monitor ambient AC fields, so have a sens coil and a high gain AC audio amplifier which powers a meter.

Another type of sensor monitors ambient electrostatic fields (static electricity). These are simple to construct and have high sensitivity.

Hope this helps.


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 Posted: Jun 6th, 2014 02:02 AM
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Jan
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I'm not sure there is any scientific proof linking changes in EMF to paranormal activity, but it's a widely held belief, so let's assume there is...

EMF meters work across various frequency ranges. From DC to GHz. If you can find one that does all that, it will probably be a piece of professional equipment which will cost a fortune.

Sparks in post no. 2 is dead right by the way.

Are you serious enough to want to use a calibrated device that gives true volts/metre readings or one that just has a buzzer and a flashing light when "something happens"? The latter will be much cheaper and probably all you need.

Also decide which frequency band you are interested in. Don't forget to do preliminary base-line checks when nothing paranormal is happening. For example, is there any nearby electronic/electrical equipment that comes on and off that will affect your readings? Where are the telephone wires? Are there any radio transmitters nearby - including an investigator's cell phone? Can you switch the mains off during investigations, or at least switch it off, take measurements and switch it back on for comparisons readings?

Of course spirits may not make EMF fields, but change those that already exist in the environment. Remember that all those existing AC fields are almost exclusively man made. Natural ones (except those caused by lightning) tend to be slowly varying DC (static) fields and need a different device - although some meters may give both AC and DC EMF indications with ill-defined accuracy.

This Youutube video assesses the cheap and cheerful ghost-hunter type EMF meters.

If you are handy with a soldering iron, there are plenty of designs on the web. Here is just one example to build.

A friend of a friend designed and built a 'UFO' detector which is really just a magnetometer based upon a magnetic compass chip. I suspect this would be just as useful in ghost hunting as any EMF device.

(Similar UFO detectors are available on Amazon.)

Good luck and let us know how you get on.

Jan

PS: You may like to do some research into the efficacy of technical equipment in the hands of ghost hunters before you part with any cash!
 

Last edited on Jun 6th, 2014 03:00 AM by Jan

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 Posted: Jun 6th, 2014 08:09 AM
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ArizonaEvp
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Hey Jan,

Thanks for the link to the youtube video.

Correct me if I'm wrong....radio transmitters would also include communications equipment from passing  vehicles like CB radios and law enforcement.



Ron

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 Posted: Jun 6th, 2014 08:30 AM
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Jan
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Hi Ron,

Well there are lots of Youtube videos showing various EMF meters. Most of them seem to be made by users, not retailers which makes a nice change. Unfortunately any relevant scientific analysis linking their use with ghosts/spirits is usually conspicuous by its absence.

(Sorry, I'm being over cynical again.)

Yes, any radio communications transmitter will emit an EMF signal - and not necessarily only when it's transmitting - whether it's in a passing vehicle of fixed somewhere else. But it may not show up on an EMF meter sensitive to a different part of the spectrum.

For example, a microwave EMF meter won't be sensitive to CB transmissions or AC mains fields.

Most devices seem to be aimed at those who perceive a threat from EMFs, so cover from mains frequencies to a 100 kHz or so, then jump to the GHz range.

But for all I know most spirits may do stuff at 29 MHz (reference Spiricom!) but many EMF meters don't even operate there.

By the way, the phrase 'tri-field' meter gets banded about in the videos without any clear explanation of what that means. It appears to refer to the meter's ability to react to AC magnetic, electrostatic and electromagnetic fields, usually by switching the sensing device.

Janet

Last edited on Jun 6th, 2014 09:51 AM by Jan

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