Hi Dave, I think you're asking the wrong people. :o)
Try an auto mechanic. My Suzuki motorcycle has two
fuel level sensors, they are 2-wire thermistor type
and with 2 sensors this gives 3 total fuel levels
that can be sensed.

These are a self contained metal "blob", with no
moving parts. From what I can see they sense the fuel
level by temperature difference between fuel and air,
and probably by heating themselves a tiny bit they
can easily detect if they are surrounded by air or
fuel.

You may be able to use a simple thermistor, heat it
by setting the PIC pin to output, then switch the
PIC pin back to input and see how long it takes to
change state.

No sane person is going to start running electricity
through fuel?? Please??

Reducing the sloshing is easy, buy some "fuel cell
foam" from a hotrod shop and stuff it in the fuel
tank. Common problem, common solution. :o)
-Roman


Dave VanEe wrote:
>
> The tank will be in a racecar travelling at speeds up to 100mph.  There will
> be sloshing (some effort will be put in to reduce this).  The float idea
> seems to require excess mechanical components.  Weighting the tank is not
> really an options since that's extra weight on the car.  If I had the need
> for a full range of fuel levels I would use a float for sure, but since I
> only need a few values I figure there's a better (easier) method out there.

> >>Hello,
> >>I'm trying to make a simple fuel level indicator for a fuel tank.  I only
> >>need to be able to sense a few levels (i.e. Full, ~1/3 full, Near Empty).
> >>I'm thinking of having two wires (or other electrical contact)
> actually -in-
> >>the gas, and using the fuel to "close the switch".  I'm pretty sure this
> >>would work for water, but I don't know if the gas will be able to conduct
> >>electricity well enough.  There is also the ignition issue, but at the
> >>voltages I'd use it shouldn't matter.  I will be using 94 Octane gasoline
> >>for my purposes.

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