This is a really nicely done project!. I wonder, what's the range of weight that you're trying to address with this? Is there a reason you use this hydraulic approach rather than load cells?
Thanks Louis. Typical weight range for my project about 500 to 1,500 lbs. I sourced an amplifier chip specially made for load cells, but I found good load cells were expensive - so much so that a scales built with load cells would not be much cheaper than just buying cattle scales. Hydraulics and pressure transducers were much less expensive.
re: Typical weight range?