Originally Posted by Volume
I was always wondering, how capacitive fuel level senders in large aeroplanes account for the different fuel qualities. In some motorgliders, you have to switch your fuel level indicator according to the type of fuel you filled in (Avgas/Mogas) because the dielectric properties are different.
In large aeroplanes you can often also use different types of fuel (Jet A-1, JP-4, Avtur...) with different additives (anti icing, anti fungi...). Still you donīt have to change any settings on your fuel level indicator system. How does this work ???
There is a compensator probe in the lowest part of each tank to which the other probes are referenced. These are checked along with the other probes in each tank during each routine calibration, which happens every 630 flying hours in the organisation I work for.