Where is DA?

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Oct 25, 2003 | 07:14 PM

critter

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From: Goshen, IN

Where is DA?

I notice everyone posts DA with times. Where do you all get it? Are there inexpensive, accurate weather stations around now? Used to use sling psychrometer and barometer, but PITA ...

Oct 25, 2003 | 07:39 PM

RUQWIKR

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From: Back home in Texas!!! (DFW)

Quote:

Originally Posted by critter

I notice everyone posts DA with times. Where do you all get it? Are there inexpensive, accurate weather stations around now? Used to use sling psychrometer and barometer, but PITA ...

I wish everyone would use the same formula for Density Altitude just to compare apples-to-apples. I use the info from the National Weather Service as well as its formula for DA as per the attached. I see guys quoting that they were running in 29.2 baro, no way 99% of the time, unless they are running inside one hell of a storm. Anyways, plug in your baro, temp, and dewpoint...lots cheaper this way than owning your own weather station. I own one for bracket racing, but never take it to the track on test & tune days like tomorrow (hopefully). Take care.

http://www.srh.noaa.gov/elp/wxcalc/densityaltitude.html

Oct 25, 2003 | 08:03 PM

JNorris

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From: Montgomery, AL

Don't you also have to add the ground elevation of the track to the result of the DA calculation?

John

Oct 26, 2003 | 04:29 AM

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From: Back home in Texas!!! (DFW)

Quote:

Originally Posted by JNorris

Don't you also have to add the ground elevation of the track to the result of the DA calculation?

John

Yes...to be exact, but most people don't know their track's altitude. Below gets you station pressure.

http://www.srh.noaa.gov/elp/wxcalc/s...pressure.shtml