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Anonymous Poster #1

Atmospheric Pressure vs. Altitude for Dry Air?

08/01/2012 11:02 AM

Atmospheric Pressure Vs Altitude, standard data given is for Dry air or moist air? If moist air, what is the RH% considered?

Ex. Sea Level Pressure is 101.3 kPa. Because humidity is not mentioned.
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Doorman
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#1

Re: Atmospheric Pressure Vs Altitude for Dry air?

08/01/2012 11:17 AM

Review these standard conditions for temperature and pressure, or STP.

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BDThompson
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#2

Re: Atmospheric Pressure Vs Altitude for Dry air?

08/01/2012 1:51 PM

Can you provide a brief description of your application? How is this information going to be used?
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lyn
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#3

Re: Atmospheric Pressure Vs Altitude for Dry air?

08/01/2012 2:26 PM

Check out "density altitude calculations".

Not sure what you are trying to accomplish.
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Sceadwian
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#4

Re: Atmospheric Pressure vs. Altitude for Dry Air?

08/01/2012 5:41 PM

The RH of a sensor can't be used to correct the pressure vs altitude at a point, it could be 95% near the sensor and 5% 100 feet up, or go up to 1000, it has no scientific correlation to pressure outside of sensor operation itself.

The requirements of %RH for the standards that specify them is probably for sensor durability testing, linearization, or to establish an acceptable operating point.
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PWSlack
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#5

Re: Atmospheric Pressure vs. Altitude for Dry Air?

08/02/2012 3:21 AM

Google "International Standard Atmosphere" and "psychrometric charts".

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dhayanandhan
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#6

Re: Atmospheric Pressure vs. Altitude for Dry Air?

08/02/2012 4:55 AM

Dear Friend,

To my knowledge, it is neither totally dry or totally saturated air and 60 % RELATIVE HUMIDITY is considered for Air.

Let us see what other CR4 Members, express their views.

DHAYANANDHAN.S
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BDThompson (1); dhayanandhan (1); Doorman (1); lyn (1); PWSlack (1); Sceadwian (1)

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