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Name: Mike
Status: other
Age: 40s
Location: N/A
Country: N/A
Date: 2000-2001


Question:
Assuming standard day conditions, what is the air pressure at 6200 feet in psi? If I remember my high school physics it is 14.7 psi at sea level. Are there tables or charts that show the relationship of air pressure to altitude factoring in variables such as temperature and relative humidity?


Replies:
Mike -

Let me answer part of your question.

If you use inches of mercury (29.92 in hg is standard) you can subtract one inch of mercury for each thousand feet up to about 18,000 feet and be fairly accurate. For your 6200 feet this would be 6.2 in hg less... 23.72 in hg. If you wanted to make it PSI you could set up the ratio and convert it. Hope this helps.

Larry Krengel


Mike,

PSI units are not ordinarily used for atmospheric pressure, mb (millibars) are. Sea level pressure is approximately 1013 mb, or 14.7 PSI (as you said). Atmospheric pressure in the lower part of the atmosphere drops approximately 10 mb in 100 meters. For 6200 feet (1889.8 meters) the pressure drops to 824 mb, or 11.95 PSI. This is an approximation of course, as various weather patterns and conditions can cause it to be somewhat different.

David R. Cook
Atmospheric Section
Environmental Research Division
Argonne National Laboratory


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