Having external sensors is no guarantee that they always will work. My SOB has three sensors glued to the side of each tank at 1/3 increments. Usually it works fine but it’s been “stuck” a time or two. One thing worth noting is that to top sensor is a fair ways from the top of the tank so I’ll get incremental readings of 1/3, 2/3 and full with a small margin for continued use.
__________________
|