Vibration

Tom Dixon <tom.dixon [at] ngv__vic__gov__au> writes

>Having a new building without a known history of vibration I don't
>know if there is a real threat to vulnerable works of art due to
>vibration from the diesel trains or any other source or not. I'm
>looking for ways to determine if any display walls, showcase
>locations or floor areas have enough vibration to damage a work of
>art.  It would be nice to have a device I could leave for a day or
>two in a display space and then read and have a record of vibration.
>There needs to be a quantifier in order to know if the vibration is
>enough, for example, to endanger a pastel drawing or that metal
>items might shake enough to move along a shelf in a display case....

The situation Tom Dixon describes sounds as if it could be easily
monitored using a RD298 ShockLog shock and vibration monitor.  This
device is manufactured by Lamerholm Fleming Ltd., and marketed by
Lamerholm Fleming <URL:http://www.shocklog.com/rd298.html> and by
Shockwatch
    <URL:http://www.shockwatch.com/products/
        intermodal/shocklog-index.html>

        **** Moderator's comments: The above URL has been wrapped
        for email. There should be no newline

The RD298 pairs a sophisticated datalogger with a tri-axial
accelerometer; accompanying software allows the user to select the
operating range of shock and vibration to be monitored (from 1g up
to 100g).  With the 1g range selected, the RD298 can detect and
record shock and vibration events as small as .05g. As expected,
this device comes with a price tag a bit heftier than that of the
TinyTag (The last time I checked, the RD298 was retailing for around
2400 USD through Shockwatch and a bit more through Lamerholm
Fleming), so there is a cost to gathering the sort of information
described in Dixon's posting.  If this is a one-time need, it may be
more cost-effective to purchase the monitoring as a service, rather
than purchasing the equipment and carrying out the study in-house.

Another aspect to consider is whether the level of sensitivity and
accuracy offered by this device is necessary and appropriate for the
task at hand.  While the RD298 can monitor events down to .05g, is
it necessary in this instance to quantitatively define unacceptable
events with that degree of accuracy, or is saying that less exposure
to vibration is better than more a sufficient assessment?  If the
latter is true, it may be more constructive to put resources towards
purchasing low-tech, cost-effective vibration dampers and employing
them throughout the facility, rather than investing heavily in
monitoring devices or services.

Will Jeffers
Collections Care Scientific Research Assistant
Department of Scientific Research
Museum of Fine Arts
465 Huntington Avenue
Boston, MA 02115
USA
617-369-3466
Fax: 617-369-3702


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                  Conservation DistList Instance 16:28
                 Distributed: Tuesday, October 22, 2002
                       Message Id: cdl-16-28-002
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