Fuel Tank Calibration - Capacitance

[skypilotusa]

I went through the fuel tank calibration steps and it seemed all was fine. But, after my first initial flights, and top offs... I continue to get Fuel mis-match pop-ups. The tanks read about half full with a "+12" indication. I selected the "Match" option within the pop-up message. My question is... Is there a way to fix this issue without draining the tanks dry? I have no way of storing 10 to 15 gallons of 100LL. and I am nervous about running the tanks low, since the gauges seem to be inaccurate.

 

[TRCsmith]

"and I am nervous about running the tanks low, since the gauges seem to be inaccurate."

Nothing to be nervous about, until you have a good answer manage your fuel the way you did before SV came along.  :

 

[swatson999]

Which converters do you have? The Dynon ones, or some others (Princeton)?

 

[skypilotusa]

Yep... I understand, I am sticking it now. In the RV I can accurately stick to about 8 gallons per side. I took the time to mark my stick in 1 gal increments, so I have a real good idea above the 8 gallon mark. I have a fresh overhaul, so fuel flows are high... we calculated 12.1 gph at this junction. I know I can tweak the voltage a bit at a time inside SV... I am expecting to have to drain the tanks and start the calibration process over. I was hopeful the gauges could be calibrated a bit more accurate than cessna gauges...

 

[skypilotusa]

Steve... I have the Dynon Convertors...

 

[swatson999]

As much as I *love* my Dynon stuff, the capacitance to voltage converters they offer are, IMHO, sub-par. They use only a tiny range of 0-5V, and I had a bear of a time with them. Switched to Princeton 2-point converters (you calibrate them to empty and full, and they use the full 5V range), and now it's just a matter of some slight adjustments in set points (they're already within about a gallon at all points).

Ditch the Dynon units and install the Princetons.

 

[Edwardoc]

Whats a source for the Princetons and are they a direct replacement, i.e. just rewire and calibrate?