Beta-radiography plates

Siew Wah Lee <lee_siew_wah [at] nhb__gov__sg> writes

>Beta plate is used for recording watermarks on paper. It contains
>C14 inside a sheet of polymethyl methacrylate, and gives out Beta
>radiation. I would like to know whether people are still using it
>for imaging watermarks, as the plate do gives out radiation, i.e.
>radioactive. Also what are the health and safety considerations in
>terms of storage, handling, exposure, etc. in the conservation lab.

We still have a beta radiograph though the plastic is now
degrading--there are lots of little crazed marks all over it. The
University Radiation protection supervisor inspects it every few
years. It is kept in a metal box in a cupboard which has a radiation
sign on the door. The room it is in also has a radiation sign on the
door--this is for the benefit of the fire brigade should they have
to enter the building in case of fire--to warn them that there is
this material present. Handling instructions are wear nitrile
gloves. It gives out very little radiation and we are advised that
it is quite safe to use. There are no restrictions on exposure time.
Liz

Liz Branigan
Senior conservator
Conservation Unit
Durham University Library
Palace Green
Durham DH1 3RN
+44 191 334 2931


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                  Conservation DistList Instance 24:48
                  Distributed: Tuesday, April 19, 2011
                       Message Id: cdl-24-48-003
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