I've been struggling with three of the standards for media storage -- and how
In order to better understand the commonalities and differences of
SMPTE RP103-1995 and
NIST Draft SP 500-252 I created a graphic and it can be found linked from
Notice the very small area of temperature and humidity that all three
standards suggest. 15-17 degrees C and 25-30% RH.
As some of you may recall, before I left for summer vacation I had discussed
a tape which had healed itself when stored in my home studio. This tape had
previously shown binder degradation (but not sticky shed).
We ran a temerature humidity logger on the storage environment for the month
of July at the particular archive and found worst-case daily variations in
humidity levels from 50-75%, with peaks occuring at about 2AM. We
subsequently learned that they went to full outside air in an "economizer"
cycle during that period...and we initially wondered if they were washing
parts of the collection every night! Also, the temperature in the archive
varied between 70 and 80 degrees F over the same period, with weekends
showing the greatest increase in heat. During the recording period, the
average temperature jumped 5F over a 2-day period.
The tapes (which are on "white box" stock) are being transferred to two CD-Rs
and the organization is taking steps to improve the environment.