remembering the LOX-tank inside camera views from previous falcon
flights, a simple optical scale on the tankwall and some image
processing could do the trick.
you could also place a numer of fairly small reflectors inside the tank
and count the dots with a certain intensity, since refraction inside and
outside the liquid should make a difference.
with scales/reflectors on oposite walls you could even account for
sloshing ... but still all this is a lot more complex than a reliable
piece of wire in a tube.
m.
Am 15.09.2015 um 09:28 schrieb Michael Clive:
What a clever gimmick.
I think you could do something with a fixed voltage source and a
intensity sensor, as the temp drops on the LED, the luminosity
increases, because the resistance drops. IT also heats itself quite nicely.
On Tue, Sep 15, 2015 at 12:14 AM, Jake Anderson <jake@xxxxxxxxxxxxxxx
<mailto:jake@xxxxxxxxxxxxxxx>> wrote:
why not put a pressure sensor at the bottom of the tank?
If you have one at the top of the tank as well the difference +
G-force = head.
How well that's going to work with LOX and measuring a gnats wing of
difference in a 700PSI tank is left as an exercise for the reader.
On 15/09/15 17:04, George Herbert wrote:
Just had an idea. Package a thermal sensor (thermocouple,
thermistor, etc) and a small (say 1W) heater in a lightly
insulated package. Immerse. It should start warming up
predictably and fast after the fluid level falls below it...
George William Herbert
Sent from my iPhone
On Sep 14, 2015, at 9:50 PM, Derek Lyons
<fairwater@xxxxxxxxx <mailto:fairwater@xxxxxxxxx>> wrote:
On Mon, Sep 14, 2015 at 2:14 PM, Ben Brockert
<wikkit@xxxxxxxxx <mailto:wikkit@xxxxxxxxx>> wrote:
But I think my concept would put less heat into the tank
and has digital
outputs, rather than analog.
No, it looks like a digital output (because the individual
sensor
states are binary) but it's actually discrete output. Nor
can you
simply use the discretes directly as a digital word, because the
relationship between adjacent individual bits in a digital
word is
exponential while the relationship between adjacent sensors in a
cylindrical tank is linear and proportional to the distance
between
them. You *could* position the sensors so the linear and
proportional
outputs equate to the exponential positions of your digital
word...
but such an arrangement would be hopelessly coarse over most
of the
burn. The conversion isn't necessarily of any great
complexity, but
it is something you'll have to account for.
Nor does it escape the need for fine manufacturing and assembly
tolerances as the accuracy of your gauging system is (as it
always is)
directly proportional to the accuracy of manufacturing and
assembly.
D.
