capacitance D180 fuel calibration

[alwaysoutdoor]

If anybody has any experience calibrating capacitive fuel gauges to a dynon d180 please PM me so we can talk over the phone. I am VERY close to finishing my RV-7. I have the voltage to capacitance converters and know they are wired correctly because when I squeeze the yellow wire I can get the calibration number to change (what dynon told me to do) but it does not change at all when I add fuel. I have filled and drained the tanks twice and cant figure it out...my head is steaming... I have tested continuity between ground and the bnc connection on the tank and it shows zero so I know I didn't accidentally ground out the plates/wires. I am a very meticulous builder and know I built the capacitive tanks as to the plans exactly. What kind of tests can I do to see what is going wrong? I have ran out of guesses. I do not want to remodel the tanks with floats if I can help it. Please somebody hold my hand and walk me through this!

 

[rzbill]

I have the dynon adaptors on my 7A (but feeding a GRT EIS).

I measured the capacitance of the plates with a hand held gage I inherited from my dad. It ranges from 180 picofarad to 360 picofarad from empty to full. This is done exactly like you checked for continuity on the BNC but with a capacitance meter. Try to find one.

Alternately, you may be able to reach the outermost plate in the tank with a continuity probe to make sure your BNC center conductor has continuity to the tank plates.