I see that the Hall effect gauges that are on most propane tanks just need the monitor cable and
from there we would be able to build an arduino or Rasp Pi config to monitor this..
most of the other sensors I see are inexpensive but the R3Dones that go on the tanks seem
to be under lock and key by many of the manufacturers.
Rochester says they only sell to "remote monitor OEMS"
http://www.rochestergauges.com/products/R3D.html
has anyone found a source for the remote monitor cable and sensor?