Subject:  (Scherer) (Ward) Re Shielding schoolroom from EMF.....
Date:     Thu, 5 Nov 1998 124607 -0600 (CST)
From:     "Roy L. Beavers" <rbeavers@llion.org>
To:       emfguru <rbeavers@llion.org>
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---------- Forwarded message ----------
Date: Thu, 5 Nov 1998 13:33:53 +0000
From: "Wolfgang W. Scherer" 
To: "Roy L. Beavers" 
Subject: Re: (Ward) Re: Microwave News, September/October 1998 (fwd)

Hi Roy 
in response to the question 
how to shield a class room  from microwaves
there are unfortunately only moderate possibilities
besides turning them into a shielded metal  cage.

Also normally classrooms have large windows
 and to shield them is the most difficult part 
with unshielded windows the remaining efforts
 shielding walls, ceiling, ( perhaps even floor) are in vain

And for windows the only available solution
 (developed for military radar sites) 
 are gold, silver or copper plated glass panes ( quite expensive)
but the achievable attenuation ( reduction) is only about 18 dB - 22 
dB for reasonable light transmission .
(Reference:   S.Y. Liao : Microwaves Devices & Circuits , 
Chap.2 page 54  Prentice Hall  ISBN 0-13-583204-7)

While I have seen many things advertised and even highly priced 
they do not provide effective shielding
and 18 dB would still not be enough if a transmitter is located in 
the school yard

Again it has to be said - 
only a proper distance  is the most useful anti measure.

Such towers should never be placed in school yards 
for the same reason  cellphones are banned from hospitals


Greetings
Wolfgang 


Wolfgang W. Scherer

http://www.reach.net/~scherer/p

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Reprinted with permission of Roy Beavers, http://www.feb.se/EMF-L/EMF-L.html