Welcome to the forum, Ettore!
If you are asking where on your property you should install your WS-WH2900-1 Misol, that somewhat depends on your property. Since all the sensor units are mounted together as a group, any location is likely to be a compromise.
I suggest somewhere that is sunny, hopefully away from trees and where the wind is not blocked by buildings. For many people, that means mounting the unit on a building, on or close to the roof. But since you likely will need to access the unit for maintenance, install it somewhere where its relatively easy to access the unit for maintenance.
If the above does not address what you were asking about, perhaps you could add more words so we can get a better idea of your question.
