That looks like a nice solution! The only thing I would worry about would be proper sanitation of it. Can it be disassembled and can it handle boiling?
The holes seem to be a bit small too? There might be a risk of clogging it up. Maybe there are other pitot tubes with bigger holes available...
I've not tested different conditions thoroughly, but the temperature did drop a few degrees (Celsius) during the fermentation without any big change in the measurements.
I was hoping that having two tubes would counteract any change in temperature or external air pressure from changing...
Yep. I took gravity readings along with my experiment, and I think it was fairly linear. The wort started out at 1,35 volts @ 1,043 SG and ended at 1,05 Volts @ 1,050 SG. 300 mV on a 0,025 SG range. So for 0,001 change in SG the AD reading would change 300 / 25 = 12 mV.
You would probably...
I think it's certainly one of the more viable options for the home tinkerer :)
I've done mostly sensor stuff (like temperature / pressure / switces) with the BB so far. Seems like you also use 1-wire sensors with yours?
I haven't really put too much work into it, so there's not a huge amount of stuff to share.. I'll write up what I have though. It comes without any warranties :P
The hardware setup is as simple as it can be:
The differential pressure sensor is hooked up to two metal tubes though thin...
That seems like a suitable replacement :) I have no idea why I picked the specific sensor that I used. It was probably just the first one I found that had suitable specs..
Time to come out from lurking mode I suppose! I did an experiment a while back using a differential pressure sensor:
http://www.digikey.com/product-detail/en/SSCDRRN025MDAA3/480-3660-ND/2704715
.. and a couple of tubes going in to a very ad-hoc-and-experimental fermentor vessel...