Talk:Barometric formula

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Error[edit]

Warning the imperial constants provided seems wrong

jmrog

why give the eq2 since its a special case? —Preceding unsigned comment added by 85.156.81.72 (talk) 08:28, 1 August 2009 (UTC)

The value for the Universal Gas Constant (R*) appears to be R*/M. This is misleading looking at the formula, suggest changing the SI value to 8.314 J/K-mol to match the Gas constant page. 198.135.125.50 (talk) 17:59, 23 November 2016 (UTC)

Choosing values for b[edit]

In the equations, what determines the correct value for b to be used? Given the same height in meters, I get different results depending on b. SharkD (talk) 21:00, 31 August 2009 (UTC)

In the table, shouldn't the Standard Temperature for subscript b=0 be 298 Kelving rather than 288 Kelvin? 298 Kelvin is the temperature used in the chemistry world's definition of standard room temperature conditions.

Incorrect Value for Standard Temperature?[edit]

In the table, shouldn't the Standard Temperture for subscript b=0 be 298 Kelvin rather than 288 Kelvin? 298 Kelvin is used in the chemistry as standard room temperature. —Preceding unsigned comment added by Cougar40 (talkcontribs) 16:48, 16 July 2010 (UTC)

I believe that standard temperature, when talking about the atmosphere, is actually 273K. See Daniel Jacob's "Introduction to Atmospheric Chemistry". Sean Egan (talk) 18:48, 24 October 2013 (UTC)

Equations and Units[edit]

Equation 2 is necessary for isothermal regions of the atmosphere, such as the stratosphere starting at a geopotential altitude of 36500 ft. It is therefore not a special case, and necessary to any full understanding of the regions of earth's atmosphere. I believe that there are two separate isothermal regions.

Regarding units: the kelvin temperature system should not be used with a foot, pound, second unit system, or english units. The proper temperature system is degree Rankine, which is a temperature system with 0 degrees at absolute zero, and increasing at the same rate as degrees farenheit (1.8 degree Rankine = 1 degree Kelvin). I suggest a change in the constants used to reflect a realistic system of units, as unsuspecting users will not check this.

Further, these equations are often used in aerospace settings, where the specific gas constant is used instead of the universal gas constant. This should be mentioned with a link to the article discussing these two different physical values. Rspecific = R/M, where R is the universal gas constant and M is the molar mass. Also, lb-mol is not the same as the SI mole. — Preceding unsigned comment added by Spcaeguyformertah (talkcontribs) 23:15, 22 January 2011 (UTC)

Challenge[edit]

The section, Estimating the Temperature should be removed. It is completely irrelevant to the article, contains zero references, and its inclusion is simply confusing.173.189.77.96 (talk) 19:43, 13 April 2014 (UTC)

Rather useless[edit]

The equation here is rather useless. It is typical to actually measure pressure and use this to calculate altitude, not the other way around.Lathamibird (talk) 13:17, 29 July 2014 (UTC)

Error in Pressure Equation 1[edit]

I think there is an error in Pressure Equation 1.

see also https://en.wikipedia.org/wiki/Atmospheric_pressure — Preceding unsigned comment added by Gimusi (talkcontribs) 08:41, 6 December 2015 (UTC)

Special types of kilometers ?[edit]

AFAIK the SI-system has no such unit as a "geometric meter". It doesn't have a "geopotential meter" either.

See #9 and #11 at this page: http://physics.nist.gov/cuu/Units/checklist.html

I therefore suggest that this part: "There are two different equations for computing density at various height regimes below 86 geometric km"

- is changed to this: "There are two different equations for computing density at various geometric height regimes below 86 km"

And in this part: "(84 852 geopotential meters or 278,385.8 geopotential feet)"

- "geopotential" should not be placed between the numbers and the units, so that part should be rewritten too.

T.O.K. — Preceding unsigned comment added by 37.253.241.7 (talk) 00:38, 8 February 2017 (UTC)