Once again, awesome feedback!
The device's form is similar to that of the glass hydrometer and it floats within the vessel as a buoy. The s.g. sensing mechanism is the innovation above and beyond the other features (i.e., wireless, temperature, buoy geometry, etc.) and accounts for the majority of the assembly cost. Temperature is the "easy" part - and this of course is reported as the fluid temperature rather than jacket temperature (although they may not significantly vary, especially if the vessel itself is inside a controlled chamber).
Great comments on pricing and the target user -- as you probably can surmise, these are big questions for us. We could do a "temp only" wirelessly for $50, but the SG measurement device for initial introduction will still be ~$179 as there is some complexity to it. If the prevailing desire is to eschew datalogging/trending, we could remove some functionality on the receiver/display end to create a "budget line SG" model.
A port in the lid of the conical SS fermenter does wonders for getting the wireless signal out - we're surveying to see if there are any configurations that don't have such a feature. Question is whether the slopes on the conical vessels are steep to the point where the buoy might touch the bottom surface if it floats near the perimeter...we'll be doing some focused testing here.
The housing is made of food grade plastic, so the sterilization is fairly straightforward. Still has to be done, no "auto-clean" feature yet...
Sincerely appreciate all of your thoughts & ideas