I just had a look around and they are not nearly as expensive as I had imagined. Running costs look manageable. Given how it works, am I right that there is always a considerable stream of waste water that often even exceeds the cleaned water?
I see you posted this week ago so I am probably way too late and the beer is already in the fermentor, but I think you'll be absolutely fine. This weekend is batch 37 for me and all 36 that came before were 5-USgallon BIAB in an 8 US-gallon pot. I mash variously with 3 - 5 gallons of water and...
I am happy to accept the short answer is no. It is always going to be interesting to see what you get and some information must be better than no information, but my question is not entirely flippant.
I have been searching through all the water threads in here and I can find very little...
USA.
And as for what I would do with it, well the same as every other hygrometer I have ever been able to lay my hand on: http://www.kandrsmith.org/RJS/Misc/Hygrometers/calib_many.html