On 16 Sep, 19:41, Bruce wrote:

The only time these are
relatively accurate is on level ground without agitation. Many (most?) aircraft
are not refuelled in a flying attitude so the initial reading is inaccurate,
then in flight the wet stuff is sloshing around - challenging to read accurately
with a float. Which is why sight gauges are so popular - and the accurate light
aircraft fuel gauge is an oxymoron.

Who said anything about a float? I can think of three ways of doing it
without one, and that's off the top of my head in ten seconds. There
will be many, many others.

Ian