Measuring Altitude

[Heelandtoe at aol.com]

You can get a rough idea of altitude by comparing the baro measurement to an 
altitude vs pressure table from the standard atmosphere model.  In rough 
terms, in the first 10,000 ft of the atmosphere the pressure decreases about 
1 inch of Mercury per 1000 ft.  So at sea level, if you are seeing 28.92 in 
Hg (29.92 would be the standard value), thats roughly equivalent to about 
1000 ft altitude on a "standard day".
jc




Hi All,

You know you hear drag racers talk about "the air is at 1000ft" etc, is it
possible for an ECM to work this figure out from it's sensors?.
I must admit I don't know what variables it takes to do this, but I assume
Baro must be one of them, and most ECM's we talk about do take a snapshot of
that at some stage.
Any idea how you could achieve a once off 'altitude' reading?.

Bye,
Ross Myers
Melbourne, Australia
E-mail : ponty at axis.jeack.com.au
Stuff : http://www.jeack.com.au/~ponty
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