Jim Weir wrote:
Charlie England
shared these priceless pearls of wisdom:

-Jim or anyone else who has 'been there',
-
-Are circuit boards available for the capacitive fuel guages featured in
-the year2000 Kitplanes articles?

Unfortunately, no. For a couple of good reasons. One that I know you
understand is liability. While I have no good reason to believe that the design
is anything but triple-redundant safe, the Denver case outlines that anybody
whose name is anywhere on the airplane will get to explain to a particularly
picky black robe why their part of the airplane could not have possibly been
involved in the accident.

Two is that I get about one request every six months for a circuit board. That
makes it economically unfeasable to even do the layout, much less make a hundred
boards and have a 50 year supply sitting on the shelf.


-
-Or (more desirable to me) is there an easily fabricated optical sensor
-available for fuel level measurement?

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.


-
-Other options???


I've been particularly intrigued with the possiblity of using the Polaroid
autofocus sonar setup but have never investigated it. THAT is damn near totally
failsafe.

Jim

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com
There are currently available liquid level sensors that use a light
source feeding a plexiglas rod with the sensor (IIRC) adjacent to the
light source. Change in refraction between covered/uncovered end of the
rod causes a 0/1 change in output state of the sensor. These are
typically promoted as low-level sensors. I am hoping for a variation on
this sensing technique. I've seen proposals for multiple rods/sensors,
but no 'cookbook' & parts source to build one 'cheap'.

Charlie