I believe I saw a posting a year or more ago that that will work with out
the light. If I remember correctly the light from the cockpit will be
reflected when there is no fuel and will be dark when there is..I thought
about using this on an ultralight gas tank. Buy a standard 5 gallon gas can.
install a fuel pick up in the lid and the fuel gauge sensor in the vent.
When I need gas I can unsnap the the bungee cords, pull the cap and vent and
take the whole thing down to the gas station and fill it up, and the FAA
want be able to claim my tank is too big.

Cheers
Jeff
"Bill Daniels" wrote in message
...

"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