Humidifying nitrogen for anoxic treatment

Will Jeffers at the Museum of Fine Arts, Boston asked for input
about moisture levels when using Ageless and compressed nitrogen.

Although I don't usually adjust the moisture levels when purging
envelopes containing wedding gowns, I did have a formula worked out
with the help of the CCI. I was concerned with the possible effects
of the extreme dryness of the compressed nitrogen. My memory is that
a quick calculation determined that 1 drop of water was needed for
every liter of dry nitrogen in the envelope to bring the humidity to
50%.  I would estimate the volume of the envelope, use an eyedropper
to wet a small scrap of rag tissue, and place it in a corner of the
bag just before purging. I would confirm the number of drops/liter
before proceeding with a sensitive item, but the method is simple
and effective.

Jerry Shiner
Keepsafe Systems &
Forever Yours Bridal Gown Preservation
Toronto, Ontario


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                  Conservation DistList Instance 13:39
                 Distributed: Monday, January 10, 2000
                       Message Id: cdl-13-39-003
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