RV-12 Fuel Totalizer

[Boat]

I have an RV-12 with a Rotax 912 ULS engine. It's my understanding that the HDX has a Totalizer in it.
The RV-12 has a fuel return line to the tank. How do I get the Totalizer to work accurately with this setup?
Someone said I need a fuel flow unit on the return line also. Will the Dynon subtract the return flow from the fuel that is pumped from the tank?

 

[Rhino]

Yes.

 

[bbaggerman]

I had the same question with my RV-12. The standard RV-12 install does not have fuel flow metering in the return line. Instead fuel burn (which I guess would be total fuel flow - return flow) is calibrated for cruise power. At other power settings like idle it is incorrect. The rationale is that most of the time is at cruise power so that is good enough. At least that is what I was told.

The other thing with the RV-12 is that fuel level display is what is measured by the float in the tank, not the totalizer. I haven't discovered how to show what a totalizer thinks might be left in my tank. I guess I could bring it up by bringing up the dialog used when adding fuel to the tank but nothing on the main display.