[Strawbale] EMR clarification

[Michael Colvin]

I may be misunderstanding what I have read to this point, but it seems to me
that some misconception exists that wire mesh will actually attract EMR the
way a magnet attracts iron filings.

Radio frequency radiation is not magnetic.  An antenna, for instance, is a
passive receptor of radiated signals.  It's ability to dectect RF at any
given frequency is based upon the principle of resonance, which is a factor
of the antenna's physical characteristics (i.e., the length of it's elements
and the direction those elements are pointed).  EMR is found throughout our
environment.  In most instances, it is in the form of extremely low voltage
(in the range of 10ths to 100ths of a microvolt [which is a millionth of a
volt] from everything from your local radio and TV stations to Radio India
broadcasting from New Delhi and from pulsars at the edge of the universe to
the computer monitor in front of you.

The wire mesh that we have been discussing acts to some extent as a passive
shield, particularly if it is well grounded, for EMR at most
frequencies from sources outside of the walls of your house.  It will not
protect you from EMR generated by your TV set, microwave, or computer
monitor.  The radiation from those sources, however, has been greatly
reduced since 1993 when new radiation safety standards for such devices
were put in place.  Under no circumstances will the wire mesh attract
EMR--it is merely a passive receptor of ambient radiation.

Grounding of electrical equipment from a physics and safety standpoint is
critical, not only to prevent shock hazards, but to reduce ambient EMR.
That's simply good safety and physics.

Michael Colvin W6CUJ
American Red Cross