Difference between old-fashioned and Modern guitars http://www.rdiaz.org/rd-art%207.html
Humidity advises http://youtu.be/-cmX9o-gf4k?t=14s
1)
You should have a hygrometer (a simple one like this:
(*do not leave this sensor inside the case, it should be outside in the room you keep the guitar)
http://www.stringsbymail.com/store/index.php?main_page=product_info&cPath=2_405&products_id=4956
and only if it is under 40% humidity place (generally in winter time) the simplest humidifier in the head of the guitar case re-filling it with water every 2 or 3 days.
2)
Here is the link for the humidifier:
http://www.stringsbymail.com/store/oasis-original-blue-currently-not-blue-soundhole-humidifier-1656.html
( this may be an useful link https://www.taylorguitars.com/sites/default/files/10_SymptomsofaWetGuitar.pdf )
The difference between Classical and Flamenco guitars http://www.rdiaz.org/rd-art%207.html
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http://www.conrad-electronic.co.uk/ce/en/product/646451/Oregon-Scientific-WMR200-Touchscreen-Wireless-Weather-Station?ref=list
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De-humidifying & proper humidity control https://youtu.be/7P8gGK4944A?t=14s