DHT22 Humidity datalogger

by luckyresistor.me:

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.

DHT22 Humidity datalogger  – [Link]