Hi Cosimo,
Here's my 0.02€ worth:
My first instinct was to use the word "production version" or "production ready" to separate from the prototypes, but it might sound a bit funny if the buyer does some of the assembling (depending on the context). And I guess measuring weather parameters is not always seen as a service that someone would need to "produce" (and be responsible for).
Maybe "field ready" would be better? If the differentiating factor is that ACRONET devices can be installed on the field. And either define somewhere what is needed for something to be field ready, i.e. watchdog and IP protection you mentioned (I assume former means that device alerts the user if there's a fault, latter means secure communications?).
"Field hardened" might also work, if the key differentiating factors center on weather protection & design that withstands knocks and so on. But you should ideally be able to play football using an operational weather station as a ball...
Hope this was of some help!
Matti
PS. Was this the other project you mentioned:
www.arduino.cc/ ?