Pauln,
I know you mean well by sharing the info you have, so please understand
my comments are general ones, and not directed at you.
It's an MD's job to radiate signal.
A metal detector is an "Intentional Transmitter". It's entire function
is to radiate a field into the ground, and then measure the reflections.
Is it dangerous to your health? Not in the least unless you have
implanted electronic devices, and then you just need to stay a
couple feet from the coil itself.
First off, the testing is done in "open air", meaning there are thousands
of RF signals floating about, and going every which direction. How did
you know that the signals you're measuring are from the detector, and not
some other nearby source?
As for the "meter", well, it might be suitable for some relative measurements,
but no one should expect any kind of accuracy from such a device. You want
a
real probe for this application?
Start here:
Health & Safety - Probes & Monitors| ETS-Lindgren
Best be prepared to spend
several thousand dollars for a quality
probe that has been calibrated for accuracy. (same for detecting
"ghosts", as that meter they walk around with is a complete joke.)
If you review the literature that came with your detector, there is mention
(somewhere) about the FCC and European standards the device has been
tested to. These tests are typically done in an anechoic chamber, where
there are no other RF signals present. The tests done must follow an established
procedure as outlined in the specific standard being tested to, and no device
can be sold
without meeting these requirements.
The supposed EMF being measuring at the headphones is caused by the
vibration of the speaker magnet. The sounds we hear are acoustic frequencies,
so yes, when that magnet vibrates it creates an electro-magnetic response
in the 20 to 20,000 Hz range which the organs in our ears process and send
to the brain for recognition.
During the EMC testing phase of the product the entire unit is tested, and
this would include testing the detector with headphones. The detector
manufacturer does not make the headphones, but they do insure there
is no chance of
conducted interference on that cable.
If you have a worn cable with bare wire showing, or bad connector
it is possible
for your machine to radiate undesired signals, and it will also dramatically affect
the performance of the machine itself. These unintended radiated signals should
still not be strong enough to harm the health of anyone.
There ARE recommendations made by most of the electronic heart device manufacturers
that metal detectors should be kept a min. of 24" from the chest area where the
device is implanted. So, if you have an implanted heart defibrillator or pacemaker,
don't lay down on the coil, or sleep with it.
If you are serious about this concern, then the best way to deal with it is
to have your detector tested at a righteous, independent EMC test lab.
They can place the unit in their chamber, and can run all manner of tests
for you about how much and how far the signals radiate. It's not cheap,
at all, and lab rates are typically in the $500 hr. range. Still, if you are
worried about the issue it might put your fears to rest.
You can also do a Google search under: "EMC testing of metal detectors"
("EMC" means Electro-Magnetic Compatibility)
No idea where you are in the country, so check for a local EMC testing
facility in your area. Some have several offices, and from personal experience
I can recommend a few:
NorthWest EMC
CKC Labs
UL Labs
There's enough crap in life to fear, and getting cancer from your metal
detector ain't one of 'em.
Perhaps someone from White's, Fisher or one of the other large manufacturers
will jump in and share what standards they test to, and what methods are
employed in the testing.