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Message
PPump manufacturers provide flow charts
that will give you
the flow rate against a head pressure. Davie-Craig's
chart even
provides this information for various voltage levels.
Measuring a
differential pressure across the pump and it's input voltage
is trivial
enough. Reference the chart, and (unless someone is lying)
you
have a dependable flow rate.
Why use charts, and
pressure, and voltages to calculate what I can directly measure with a
flow meter?
The one caveat is that
the flow meters are all calibrated to the specific gravity of water, so
they won't be completely accurate with Evan's NPG. I'm sure there's a
conversion if I look up the specific gravity of Evan's, or just ask them to
convert it, but getting a directly measured number will be the place to
start.
The next problem is that
this number means nothing, since we don't have a known minimum flow number
to shoot for. People have measured the stock flow, but no one can say if
it's necessary to have that much, or just a necessary evil of providing
flow at idle, and being forced to also run 7500 rpm.
Still looking at flow
meters anyway. BTW, thanks for the info Todd, but I can't find a price on
those meters. I also suspect they're fairly pricey. I'm looking at
something mechanical, to read directly, but I'm having trouble finding something
with enough range.
Hey Todd. Since
you flew with the flow meter hooked to your EM-2, just post the
datalogs of your flights. Oooops, that's right, we don't have a
datalog feature :-)
Rusty (it's Todd's
fault, really)
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