luckyresistor has been working on his Data Logger project:
There is a large cellar where I could store unused items and documents, but the catch is the humidity there. It is a root cellar near a small brook and the humidity varies between 75% up to 90%.
Archived material should never be exposed to humidity greater than 65%, therefore I have to isolate all documents in boxes from the air of the cellar. But are this boxes safe? Do they keep the humidity away from the documents – even for years?
To have a look into the box environment, I need a data logger. It would be simple to buy one, but much more fun to build one. So a new project is born: I call it the “Data Logger” project.
More details at luckyresistor’s blog.
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