Dynon resistive fuel sensor Calibration

I'm looking for an easy (clean, safe) way to do the fuel calibration on a Dynon HDX resistive fuel measuring system before the first flight.

It seems best to do the complete cal on both tanks, but that would result in a first flight with full fuel.

I thought about doing the cal on one tank, then draining the fuel from that tank incrementally and adding it to the other tank for cal. Then when done, removing half the fuel and transferring it back to the original tank. The result would be two half full tanks, plenty for a first flight.

This sounds pretty messy and honestly I'm not thrilled about handling that much 100LL with gas cans, drain tubes and absorbent mats.

Or, I could just blow it off for now and hope that some errant warning doesn't scare the wits out of me on takeoff roll!

Anyone done this before or have a sensible solution?

Thanks

Full fuel in one wing and no or almost no fuel in the other will cause a slight tilt in the bank angle of the airplane, which will affect the float reading.

I would put a half tank in one wing, then do a full call on the other side. Then drain the half-tank from the un-calibrated side and half the fuel from the calibrated side, and perform the calibration on the second side. That way you are at least holding a half-tank in balance on the other wing to split the difference on the wing bank angle.

For first flight - if you don't want to do this yet - do it by time. Say you want 30 minutes for your first flight - an IO360 is going to burn about 16 gallons per hour, a half-hour of that is 8 gallons of expected fuel burn - now add a good comfortable margin to that and load that much fuel on board. Set a timer or have a friend radio a time mark to you when it's time to land.

I calibrated my tanks prior to first flight and flew with them full.