If you stick with one type of fuel maybe but not when you switch between
auto and 100LL. The error is not one of varying mass but one of varying
capacitance. A fuel with the same calorific content may have a very
different reading on a capacitance gauge.
Jerry
LTS@avnet.co.uk
www.avnet.co.uk/touchdown
----- Original Message -----
From: "Alexander P. de C. Kaarsberg" <kaarsber@terra.com.br>
Subject: Europa-fuel contents
> Jerry wrote:
>
> "Not susceptible to fuel density changes (like a capacitance device)"
>
> "Capacitance gauges may appear more accurate because they have better
than
> 1/8th resolution but because of the variations in fuel make up they are
> often less accurate. The difference being with our gauge if it indicates
20
> litres you have at least 20 litres. Whereas with a capacitance gauge if it
> says you have 22.5 litres may have 22.5 litres then again you may not."
>
> This is not so, it's the opposite that happens, capacitance gauges are
used on large aircraft because they do show actual contents, e.g. the mass
of the remaining fuel which is what you need to know.
> When the temperature of the fuel changes, the volume changes, but the
calorific burn value is still the same. This value may change with the
quality of the fuel, but with a volumetric gauge you'll be further away from
the truth I think.
> I can however imagine that the capacity type may be difficult to get to
work well on a small aircraft and as the variation in exactitude of the
switch arrangementdue to temperature change is so small I'd go for the
simple type myself.
>
> Your wannabee fellow builder,
> Alex
>
>
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