Hi Martin, there was a similar question on the Global Conservation Forum recently with a suggestion that you could look into as well. This is just meant to let you know of an option though - as Robin said, we don't endorse any specific product. Hopefully the link works, but if not you can search "rechargeable light meter" in the online community.
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Rebecca Smyrl
Connecting to Collections Care Monitor
Assistant Conservator for Special Collections
UNC Chapel Hill Libraries
Chapel Hill NC
(919) 962-4250
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