View single post by sparks
 Posted: Jun 5th, 2014 01:12 PM
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sparks



Joined: Jan 15th, 2008
Location: New Zealand
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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.