At 10:03 AM 1/3/02 +1300, Russell McMahon wrote:
>I don't know where these utterly ludicrous ideas originated!
>
>To be at all effective you must use materials which provide magnetic
>shielding. Non ferrous materials (here Aluminium (to be confused with
>Aluminum)) do not, of course, work for this purpose.

The systems work in around 10 MHz for the inductive tags, and upwards of a
GHz for the diode mixers. Aluminum foil is an effective shield
here.  Copper works well too.

>  At the minimum one
>should wear soft iron sheet headgear and preferably a mu-metal cap should be
>employed - especially if near field radiation (in either direction) is of
>concern.

Better for DC-1MHz sorts of fields.

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads