"Jim Weir" wrote in message
...

Optical? Hmmm...with green fuel, blue fuel, red fuel, and clear fuel
around
(and we all know there's no fuel like an old fuel) I'm not sure what sort
of
optical system would be stable and sensitive enough to cover this range of
optical barriers.


Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

Well, there's brute force. Just install a closed circuit TV camera that
looks in through a window in the tank. Nothing like directly eyeballing how
much fuel there is in the tank. Make sure there is a "dipstick" in the
camera view. Hey, everybody's going "glass cockpit" anyway.

The fiber optic trick.... Just use a bundle of plastic fibers, each cut to
a different length on the tank end. In the cockpit, just break out the
bundle into a vertical array of fiber ends. Illuminate the interior of the
tank with "ultrabright" LED's. A fiber end in the cockpit will either
illuminate if the other end is submerged in fuel or go dark if it isn't.
Want a brighter display? Just install more LED's.

Bill Daniels