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It seems the more people that look at this issue the more diverse the
opinions are. As a practical matter, many want to design their storage
environments to be easily achievable (temperature and humidity
ranges),
others don't want anything said that might lead you to believe that
certain
media requires special and thereby expensive storage conditions.

When we first entered the vaulting business, we were requested to
supply the
actual heating and cooling system for a State Archive. Being naive, I
agreed. I was asked to meet the ANSI IT Standard for Long Term Storage
of
Microfilm. In researching the issue I found that Dr. Adelstein, who
chaired
the standard accomplished it by putting microfilm in Bell jars, fixing
the
humidity and then corking the jars. In short, they had no idea how to
achieve the temperature and humidity in concert, required to hold the
media
stable in the real "archival storage" world.

By working with Munters Cargocaire, we were able to specify and design
a
system which would hold 30% (+/- 2%) and 68 F (+/- 2) and meet
the
standard to the State's satisfaction. It turned out that the system was
less
expensive by half of what they originally engineered. (Of course you
have to
ignore two years of work coming up with the system.)

Due to the requirement of most media vaults to store all forms of
media,
this also became the de facto climate for magnetic media. (ANSI would
allow
a range of temperatures which lower as the humidity requirement is
relaxed
but this is inappropriate  for magnetic media as back ups are exposed
to
higher temperatures on every rotation or emergency use as a master.)
By
storing at these temperatures there was less shock to media on rotation
and
the lower humidity enhanced the stability of the media in stasis.

But more importantly, in the real world, the end-user clients
experienced a
extension in the longevity and stability of their media due to a more
stable
storage climate environment. This is based on vaults storing
microfilm,
floppy disks, 3480 & 3490 cartridges, optical disks, reels, and a whole
host
of other magnetic media. This is, of course, anecdotal experiences
based on
the requirement to store a variety of media but I believe this is the
real
[ reel? :~) ] world.

The rationale on storage is simple: media should be able to be able to
be
pulled or rotated without affecting the quality of the magnetic
strength or
exacerbate the breakdown in base material making up the recordable
media. By
storing at a temperature closer to the operating temperature of the
computer
environment a cycling effect can be eliminated. This then requires the
humidity to be lowered in storage chamber to counter balance the
higher
storage temperature. A limiting factor is that static electricity
becomes
more prevalent at humidity ranges below 20%. ( We personally experience
this
each winter when our daughter sneak up on a cold dry day and shock our
nose
while reading the paper.........well, at least I do here in Kutztown.)
Since
static discharges are to be avoided, we need to keep the humidity at
the
lowest safest range, voila 30%. The U. S. Department of Commerce
published
NIST Special Publication 500-199 by Mark Williamson which discussed
magnetic
media, expecially 3480 type media in great depth.

Another issue in storage is the quality of the air in the storage
chamber
and special care should be taken to use dust and HEPA filters to
provide
pollution and dust reduced environments. Choice of floor coverings can
also
aid you in this regard, avoid carpets and unsealed concrete floors as
they
pose risk to the media. "Well, that's about it!" said Bubba Gump to
Forrest.

FIRELOCK Fireproof Modular Vaults
Hugh Smith at (610) 756-4440
Kutztown, Pennsylvania
See our Web Site at www.FIRELOCK.COM 

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>From:    francisco barbedo <[log in to unmask]>
>Subject: Standards for magnetic media
>
>HEllo to all
>
>Does anyone happens to know if there are any standards both
international
>(ISO, IEEE, etc) or national (ANSI, BS, etc) regarding the
preservation of
>magnetic media whether tapes, cartridges or disks. Need info on
environement
>temperature, periodic rewinding, error monitoring, etc. I do know of
some
>guidelines but not of standards.
>Any help would be apreciated
>thanks in advance
>
>Francisco


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