Re: [AV Media Matters] Magnetic fields

[rohre@ARLUT.UTEXAS.EDU]

It all depends!
----Magnetic and electric fields near archives is not a good thing,
but how near is it?   Surely you are not right on the wharf?   If
you are in a metal sheathed building, or far away, magnetic effects
are reduced by distance or shielding or both.  For example, a sheet
of mild steel 3 inches from a source of 10 Gauss will shield a
medium coercivity tape by the combination of steel and distance from
any detrimental effect of that 10 Gauss source. That was an
experiment we did before setting up digital tape archives some years
ago.

Also, the radars hopefully will be up in the air, a very directive
beam, and not at the elevation of your Archive, unless you are on an
upper floor.

The radar pulse is very short, and likely will not affect your
Archive a reasonable distance away.  Or are these tapes aboard ship?
If so, they should be kept in a Mu Metal cabinet, or Steel walled
cabin, and away from any port holes, which could be accidentally
illuminated by a rotating radar aboard ship.

Regards,
Stuart Rohre
Applied Research Labs. U TX, ( a US Navy contractor)