Spectrophotometry

We are in the process of reviving the practice of Spectrophotometry
here at the Canadian Centre for Architecture. Our goal is to be able
to use our Spectrophotometer in relation to loaned and exhibited
works, to determine if a change has occurred as the result of light
exposure. This practice, we hope will allow us to prevent
overexposure to light for exhibited objects. For very specific
locations (light, medium and dark areas) on an object, we will take
before and after readings. We'll use the L, a, and b values in a
Delta-E summary to determine if a shift has occurred.

I'd like to pose a few questions to distlist recipients with
experience in this area:

    At what Delta-E value did you consider limiting an object's
    future exhibition or light exposure?

    How did you limit exposure to light after a certain concerning
    Delta-E value (i.e. create longer "periods" for the objects?)

    Has anyone given up on Spectrophotometry as a practice, and if
    so, why?

Please share any other information, resources or experience that you
might have on Spectrophotometry in practice.

David Stevenson
Restaurateur
Conservator
Canadian Centre for Architecture
1920, rue Baile
Montreal, Quebec H3H 2S6
514-939-7001 ext 1204
Fax: 514-939-7020


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                  Conservation DistList Instance 27:6
                  Distributed: Saturday, July 20, 2013
                        Message Id: cdl-27-6-027
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