Re: [AV Media Matters] Audio query

[smolians@erols.com]

I seem to remember the Cuddihy data was adjusted to a more realistic
outlook in later publications.  You might want to look at a
publication by the Committee on Preservation and Access in DC (I
can't give a better citation), by Jan van Bogart.

Steve Smolian

----- Original Message -----
From: <rohre@ARLUT.UTEXAS.EDU>
To: <AV-Media-Matters@topica.com>
Sent: Tuesday, June 06, 2000 4:34 PM
Subject: Re: [AV Media Matters] Audio query

>The prevention of moisture absorption by the archived tapes is
>paramount to
>their lasting 20 years, without the intensive labor of re- recordings
>periodically.  The TV networks have a schedule that I believe was
>3 or 5 year
>intervals when back up copies are remade, but I believe Masters are kept
>indefinitely.  But that is labor intensive, and a drain on staff time.
>
>There is no substitute for a neutral relative humidity, where no
>moisture is
>taken up by the media, and thus you must lobby to have adequate
>cool and dry
>storage.  I think Cuddihy of Jet Propulsion Laboratories, CA.  (JPL) has
>extrapolated an indefinite tape lifetime, if you keep it at 20 % RH and
>something like 40 degrees F.  My copy of his paper is not at
>hand, but there
>was a table of lifetime vs. storage conditions.
>
>There are reasonable off site environmentally controlled stores
>for computer
>archives all over the country now, and facilities without their
own vaults
>might consider the specialist's services for irreplaceable material.  Of
>course, you would still keep a Back UP copy in your own facility,
>renewed as
>needed.  This might be the best course for a museum in an older building
>without modern air conditioning plant and complete humidity and close
>temperature controls.
>
>Stuart Rohre
>ARL UTx Recording Lab