Mike, Of course, this is an option. I cut two holes in the top of the tank,
between the two headrests, and placed a mechanical float in the pilot hole,
and the other one is for upgradeability of the passenger side with the same,
or other fuel-related extras (second tank input, last-chance backup, or
whatever). The goal is to have a flow rate meter to tell the pilot how much
fuel is left, unless the tank begets a leak. Although unlikely to not have
other sensory inputs like smell, the first backup would be the mechanical
float. From reading other emails, the poly tank topside might ripple over
time. Because of its narrowness, it wouldn't take much movement (whether it
be rippling, or tank-top sender nut becoming loose, from the vibration) for
the throw of the mechanical wand to stick on the sidewall of the lower tank.
If one knew this was happening, it would be an easy matter to re-adjust the
wand in the tank. On the off chance that it snuck up on the pilot during
flight, it could make it seem that there is more fuel in the tank than
actual. Thus I like the simplicity of a third backup system being a sight
gauge. You can pretty much trust that you have what you see, if it is
installed properly. And if installed into the passenger side, it would allow
inspection of the reserve fuel, which is information that my one-float
system doesn't currently have, in its non-upgraded state. A good inspection
frequency would mitigate one caveat of the sight gauge -possible leakage due
to breakdown.
Of course, one could argue that the capacitance meter would be a good
replacement for the mechanical gauge, and it is. It would not be susceptible
to slight tank swelling due to fuel. Originally, that was my plan. But
capacitance gauges don't seem to be without their problems, either, such as
being sensitive to the different fuel additives being put into the tank. For
example, the alcohol is more conductive than the non alcoholic mogas, and
---From what I have read, different fuels will affect the reading, like
switching between avgas and mogas. This will hinder the accuracy of the
gauge, and one could argue that the float could be at least as accurate, if
not more so -if the user is not married to one fuel type. Of course, a float
is also cost-effective on the pocketbook.
I don't mean to be anal-ytical about it all, but maybe it has happened.
Anyway, that is why I wanted the sight tube. Everything is subject to
change, of course. I might just throw in a second float for the 3rd
redundancy, and be done with it. The second float may only get in the way
slightly to the fuel related extras that will probably be using the second
hole, so I am still looking at the site glass/tube solution for now.
Hopefully, this has answered your question adequately :)
Greg Fuchs (A050), over 800 hours into the beast
<mikenjulie.parkin@btinternet.com>
Why not 'bin' the sight tube altogether and fit an alternative gauging
system. I have twin capacitance probes and they work brilliantly.
Regards,
Mike
|