Why is that when people learn your a physics head they immediately start
asking you questions? :-)
At a local high power rocket launch this weekend I was asked a question
that's got me stumped.
A fellow is designing an onboard computer for his rockets that has a
pressure sensor onboard. He wants to know how to turn his pressure readings
into altitude readings as the rocket is accelerating up, decelerating up,
and returning back to earth via a chute.
I know there is an answer to his question because I have an onboard computer
(that I purchased) that uses an absolute pressure device. According to the
company it uses a logarithmic amp to accurately measure the nonlinear
pressure vs altitude relationship. After sensing a rapid 300' change it
begins taking data and then captures max alt at the same time triggering a
switch to deploy a drogue chute. A second trigger then fires at 600' (user
selectable) for the main chute.
The only thing I can come up with is the old P2=P1+(p)gh which assumes the
density is the same for any h and thus can't be used for gases. I've looked
through all my college and hs texts and have found nothing more detailed.
Anyone know the answer or who to contact to get more info?
TIA,
Jason
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Jason (and Kim and Jacob) Powell
Kenosha, WI
Our Webpage: http://www2.wi.net/~fizzx/
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Physics Dept
ZionBenton HS
Zion, IL
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'96 Red Miata[PEP]...FIZZX 1
Windy City Miata Club=> http://www.mcs.com/~hal109/windy_city.html
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"...the truth the symbol of a dove, will unmask the maker of your plans..."
King's X - Out of the Silent Planet
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