Unstable Reading from Capacitive Fuel Sensor in Right Tank – Calibration Issue

[ChrigelsRV8]

Dear Forum,

I have been experiencing a persistent issue with the capacitive fuel measurement in the right tank, which has been showing a "full" status for some time. The value does not change, even during flight.

A couple days ago, I performed a recalibration via the SkyView HDX in the EMS. During the process, I noticed that the readings after adding 10 liters of Avgas were unstable. The values fluctuated up and down significantly for several minutes. After approximately 10 minutes, the reading started to stabilize, but it remained inconsistent and not fully reliable.

For comparison, I also recalibrated the left tank, which showed perfectly stable behavior throughout the process.

I have installed the 51105 AF-Capacitance Fuel Adapters supplied by Advanced Flight Systems.

Attached you will find some pictures and videos that document the issue.

Does anyone know what might be causing this behavior, and whether there are any known issues or recommended troubleshooting steps?

Thank you in advance for your support.

Kind regards,
Christian Schaerer
Basel, Switzerland

 

[CanardMulti]

I have Princeton capacitive senders in my plane. Several years ago, after I did some upgrades that required among other things working deep in tight quarters in the aft portion of the plane, one of my fuel tanks began to constantly read full as well. After extensive trouble shooting I discovered I had inadvertently broken a ground wire - not good anytime but especially a problem in a composite airplane. Once I repaired the ground wire the gauge then read correctly. Whether or not your brand senders work the same way I cannot say, but carefully inspecting ALL the wiring from sender to EMS sure couldn't hurt.

 

[ChrigelsRV8]

Thank you for your reply. I think if the ground (or any) wire is broken, then the value would be offset or constantly read full. but the fluctuations are strange. They move up to +-0.6Volts. I ordered a ne capacitive sender. Today I will swap the capacitive senders and see what I get.