Density of Air - Wikipedia, The Free Encyclopedia

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Air density

Air density (in greek: rho)

Representation of an air sample

thermodynamic property

Volumetric mass density

List of thermodynamic properties

General information

property Air density

symbol

Variable of state yes

Type of property material

dependence of the

mass

intensive

Dimensional function M.L-3

Units kg.m-3

property value 1.2922 kg.m-3

Common units

International System (SI) kg.m-3

Imperial units lb.ft-3

CGS System (CGS) g.cm-3

Standard value(s) Air density

Calculation variables IUPAC

absolute pressure - p 100000.0 Pa

absolute temperature - T 273.15 K

Density of airFrom Wikipedia, the free encyclopedia

The density of air, (Greek: rho) (air density), is the mass per

unit volume of Earth's atmosphere. Air density, like air pressure,

decreases with increasing altitude. It also changes with variation

in temperature or humidity. At sea level and at 15 C, air has a

density of approximately 1.225 kg/m3

(0.001225 g/cm3

,0.0023769 slug/ft3, 0.0765 lbm/ft3) according to ISA

(International Standard Atmosphere).

The air density is a property used in many branches of science as

aeronautics;[1][2][3]gravimetric analysis;[4]the air-conditioning[5]

industry; atmospheric research and meteorology;[6][7][8]the

agricultural engineering in their modeling and trackingof Soil-

Vegetation-Atmosphere-Transfer (SVAT) models;[9][10][11]and

the engineering community that deals with compressed air

[12]

from industry utility, heating, dry and cooling process[12]in

industry like a cooling towers, vacuum and deep vacuum

processes,[5]high pressure processes,[5]the gas and light oil

combustion processes[5][12]that power our turbines airplanes, gas

turbine-powered generators and heating furnaces, and air

conditioning[5]from deep mines to space capsules.

Contents1 Density of air calculations

1.1 Density of air variables

1.1.1 Temperature and pressure

1.1.2 Humidity (water vapor)

1.1.3 Altitude

1.1.4 Composition

2 See also

3 Notes

4 References

5 External links

Density of air calculations

Depending on the measuring instruments, use, area of expertise

and necessary rigor of the result different calculation criteria and

sets of equations for the calculation of the density of air are used.

This topic are some examples of calculations with the main

ariables involved, the amounts presented throughout these

examples are properly referenced usual values, different values

can be found in other references depending on the criteria used
http://en.wikipedia.org/wiki/List_of_thermodynamic_propertieshttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/List_of_thermodynamic_propertieshttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/Phttp://en.wikipedia.org/wiki/File:Thermodyn_Properties_Logo.gifhttp://en.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_unitshttp://en.wikipedia.org/wiki/Imperial_unitshttp://en.wikipedia.org/wiki/Intensive_and_extensive_propertieshttp://en.wikipedia.org/wiki/Intensive_and_extensive_propertieshttp://en.wikipedia.org/wiki/State_functionhttp://en.wikipedia.org/wiki/Symbolhttp://en.wikipedia.org/wiki/List_of_thermodynamic_propertieshttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Aeronauticshttp://en.wikipedia.org/wiki/Gravimetric_analysishttp://en.wikipedia.org/wiki/International_Standard_Atmospherehttp://en.wikipedia.org/wiki/Kilogram_per_cubic_metrehttp://en.wikipedia.org/wiki/Humidityhttp://en.wikipedia.org/wiki/Sea_levelhttp://en.wikipedia.org/wiki/Atmosphere_of_Earthhttp://en.wikipedia.org/wiki/Gravimetric_analysishttp://en.wikipedia.org/wiki/Aeronauticshttp://en.wikipedia.org/wiki/International_Standard_Atmospherehttp://en.wikipedia.org/wiki/Pound_(mass)http://en.wikipedia.org/wiki/Slug_(mass)http://en.wikipedia.org/wiki/Kilogram_per_cubic_metrehttp://en.wikipedia.org/wiki/Sea_levelhttp://en.wikipedia.org/wiki/Humidityhttp://en.wikipedia.org/wiki/Atmosphere_of_Earthhttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_unitshttp://en.wikipedia.org/wiki/Imperial_unitshttp://en.wikipedia.org/wiki/International_System_of_Unitshttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/SI_unitshttp://en.wikipedia.org/wiki/Dimensional_equationhttp://en.wikipedia.org/wiki/Intensive_and_extensive_propertieshttp://en.wikipedia.org/wiki/Intensive_and_extensive_propertieshttp://en.wikipedia.org/wiki/State_functionhttp://en.wikipedia.org/wiki/Phttp://en.wikipedia.org/wiki/Symbolhttp://en.wikipedia.org/wiki/Propertyhttp://en.wikipedia.org/wiki/List_of_thermodynamic_propertieshttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/List_of_thermodynamic_propertieshttp://en.wikipedia.org/wiki/File:AirEnsemble.pnghttp://en.wikipedia.org/wiki/Rhohttp://en.wikipedia.org/wiki/Greek_languagehttp://en.wikipedia.org/wiki/Phttp://en.wikipedia.org/wiki/File:Thermodyn_Properties_Logo.gifhttp://en.wikipedia.org/wiki/File:Pix.gif


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Gas constant - Rspecific 287.058 J.kg-1.K-1

Value in calculation conditions IUPAC

Air density - 1.2754 kg.m-3

Calculation Variables STP



molar volume - Vm 22.710953 l.mol-1

molar mass - Mair 28.9645 g.mol-1

Value in calculation conditions STP


Calculation Variables NIST



molar volume - Vm 22.413968 l.mol-1

molar mass - Mair 28.9645 g.mol-1

Value in calculation conditions NIST


Calculation Variables Imperial units

absolute pressure - p 14.695858 psia (lbf.in-

2)

absolute temperature - T 491.67 R (32 F)

Gas constant - Rspecific 53.3533 ft.lbf.lbm-1.R-

1

Value in calculation conditions Imperial units

Air density - 0.080672 lbm

.ft-3

Equations

Basic equation

Ideal gas equation

Ideal gas equation (another form)

Units of SI & NIST in the field of general information,

for the calculation . Furthermore we must pay attention to the fact

that air is a mixture of gases and the calculation always simplify,

to a greater or lesser extent, the properties of the mixture and the

alues for the composition according to the criteria of

calculation.[1][2][3][4][5][6][7][8][9][10][11][12]

Density of air variables

Temperature and pressure

The density of dry air can be calculated using the ideal gas law,

expressed as a function of temperature and pressure:

where:

air densityabsolute pressure

absolute temperature

specific gas constant for dry air

The specific gas constant for dry air is 287.058 J/(kgK) in SI

units, and 53.35 (ftlbf)/(lbmR) in United States customary and

Imperial units. This quantity may vary slightly depending on the

molecular composition of air at a particular location.

Therefore:

At IUPAC standard temperature and pressure (0 C and

100 kPa), dry air has a density of 1.2754 kg/m3.

At 20 C and 101.325 kPa, dry air has a density of

1.2041 kg/m3.

At 70 F and 14.696 psi, dry air has a density of

0.074887lbm/ft3.

The following table illustrates the air densitytemperature

relationship at 1 atm or 101.325 kPa:
http://en.wikipedia.org/wiki/Cubic_foothttp://en.wikipedia.org/wiki/Pound_(mass)http://en.wikipedia.org/wiki/Pounds_per_square_inchhttp://en.wikipedia.org/wiki/Fahrenheithttp://en.wikipedia.org/wiki/Kilogramhttp://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Standard_temperature_and_pressurehttp://en.wikipedia.org/wiki/International_Union_of_Pure_and_Applied_Chemistryhttp://en.wikipedia.org/wiki/Imperial_unitshttp://en.wikipedia.org/wiki/United_States_customary_unitshttp://en.wikipedia.org/wiki/Rankine_scalehttp://en.wikipedia.org/wiki/Pound_(mass)http://en.wikipedia.org/wiki/Pound-forcehttp://en.wikipedia.org/wiki/Foot_(length)http://en.wikipedia.org/wiki/International_System_of_Unitshttp://en.wikipedia.org/wiki/Specific_gas_constanthttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Thermodynamic_temperaturehttp://en.wikipedia.org/wiki/Ideal_gas_lawhttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/International_System_of_Unitshttp://en.wikipedia.org/wiki/Imperial_unitshttp://en.wikipedia.org/wiki/Imperial_unitshttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressure


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unless otherwise statedEffect of temperature on properties of air

Temperature

T(C)

Speed ofsound

c(ms1)

Density ofair

(kgm3)

Specific acousticimpedance

z(Pam1s)

+35 351.88 1.1455 403.2

+30 349.02 1.1644 406.5

+25 346.13 1.1839 409.4

+20 343.21 1.2041 413.3

+15 340.27 1.2250 416.9

+10 337.31 1.2466 420.5

+5 334.32 1.2690 424.3

0 331.30 1.2922 428.0

5 328.25 1.3163 432.1

10 325.18 1.3413 436.1

15 322.07 1.3673 440.3

20 318.94 1.3943 444.6

25 315.77 1.4224 449.1

Humidity (water vapor)

The addition of water vapor to air (making the air humid) reduces the density of the air, which may at first appear

counter-intuitive. This occurs because the molar mass of water (18 g/mol) is less than the molar mass of dry

air[note 1](around 29 g/mol). For any gas, at a given temperature and pressure, the number of molecules present is

constant for a particular volume (see Avogadro's Law). So when water molecules (water vapor) are added to a

iven volume of air, the dry air molecules must decrease by the same number, to keep the pressure or temperature

from increasing. Hence the mass per unit volume of the gas (its density) decreases.

The density of humid air may be calculated as a mixture of ideal gases. In this case, the partial pressure of water

apor is known as the vapor pressure. Using this method, error in the density calculation is less than 0.2% in the

range of 10 C to 50 C. The density of humid air is found by:

[13]

where:

Density of the humid air (kg/m)

Partial pressure of dry air (Pa)

Specific gas constant for dry air, 287.058 J/(kgK)

Temperature (K)

Pressure of water vapor (Pa)

Specific gas constant for water vapor, 461.495 J/(kgK)

Molar mass of dry air, 0.028964 kg/mol

Molar mass of water vapor, 0.018016 kg/mol

Universal gas constant, 8.314 J/(Kmol)

The vapor pressure of water may be calculated from the saturation vapor pressure and relative humidity. It is found

by:
http://en.wikipedia.org/wiki/Relative_humidityhttp://en.wikipedia.org/wiki/Saturation_vapor_pressurehttp://en.wikipedia.org/wiki/Gas_constanthttp://en.wikipedia.org/wiki/Kelvin_(unit)http://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Partial_pressurehttp://en.wikipedia.org/wiki/Ideal_gashttp://en.wikipedia.org/wiki/Avogadro%27s_Lawhttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Secondhttp://en.wikipedia.org/wiki/Metrehttp://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Metrehttp://en.wikipedia.org/wiki/Kilogramhttp://en.wikipedia.org/wiki/Secondhttp://en.wikipedia.org/wiki/Metrehttp://en.wikipedia.org/wiki/Celsius


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The movement of the helicopter rotor leads to a difference in pressure between the upper and lower blade surfaces,allowing the helicopter to fly. A consequence of the pressure change is local variation in air density, strongest in

the boundary layer or at transonic speeds.

where:

Vapor pressure of water

Relative humidity

Saturation vapor pressure

The saturation vapor pressure of water at any given temperature is the vapor pressure when relative humidity is

100%. One formula [14]used to find the saturation vapor pressure is:

where is in degrees C.

note:

This equation will give the result of pressure in hPa (100 Pa, equivalent to the older unit millibar, 1

mbar = 0.001 bar = 0.1 kPa)

The partial pressure of dry air is found considering partial pressure, resulting in:

Where simply denotes the observed absolute pressure.

Altitude

To calculate the density of air as a function of altitude, one requires additional parameters. They are listed below,

along with their values according to the International Standard Atmosphere, using for calculation the universal gas

constant instead of the air specific constant:

sea level standard atmospheric pressure, 101.325 kPa

sea level standard temperature, 288.15 K

earth-surface gravitational acceleration, 9.80665 m/s2
http://en.wikipedia.org/wiki/Kelvin_(unit)http://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Gas_constanthttp://en.wikipedia.org/wiki/International_Standard_Atmospherehttp://en.wikipedia.org/wiki/Absolute_pressurehttp://en.wikipedia.org/wiki/Partial_pressurehttp://en.wikipedia.org/wiki/Bar_(unit)http://en.wikipedia.org/wiki/Millibarhttp://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Vapour_pressure_of_waterhttp://en.wikipedia.org/wiki/Transonichttp://en.wikipedia.org/wiki/Boundary_layerhttp://en.wikipedia.org/wiki/Lift_(force)http://en.wikipedia.org/wiki/Helicopter_rotorhttp://en.wikipedia.org/wiki/File:Increasing_the_density.png


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Standard Atmosphere: p0=101.325 kPa, T0=288.15 K, =1.225 [[kg/m3]]

temperature lapse rate, 0.0065 K/m

ideal (universal) gas constant, 8.31447 J/(molK)

molar mass of dry air, 0.0289644 kg/mol

Temperature at altitude meters above sea level is approximated by the following formula (only valid inside the

troposphere):

The pressure at altitude is given by:

Density can then be calculated according

to a molar form of the ideal gas law:

where:

molar mass

ideal gas constant

absolute temperature

absolute pressure must be in Pa and not the kPa above.

Composition

The air composition adopted for each set of equations varies with the references used in the table below are listed

some examples of air composition according to the references. Despite minor differences to define all formulations

the predicted molar mass of dry air and below table shows these differences. Importantly, some of the examples

are not normalized so that the composition is equal to unity (100%), before they used should be normalized.
http://en.wikipedia.org/wiki/Absolute_pressurehttp://en.wikipedia.org/wiki/Absolute_temperaturehttp://en.wikipedia.org/wiki/Ideal_gas_constanthttp://en.wikipedia.org/wiki/Molar_masshttp://en.wikipedia.org/wiki/Ideal_gas_lawhttp://en.wikipedia.org/wiki/Tropospherehttp://en.wikipedia.org/wiki/Molar_masshttp://en.wikipedia.org/wiki/Mole_(unit)http://en.wikipedia.org/wiki/Adiabatic_lapse_ratehttp://en.wikipedia.org/wiki/Kelvin_(unit)http://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/File:StandardAtmosphere.pnghttp://-/?-


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Composition of dry atmosphere, by volume[note 1]

Gas(andothers)Volume by various[15][note 2] Volume by CIPM-2007[16] Volume by ASHRAE[17]

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table

ppmv[note 3] percentile ppmv percentile ppmv percentile

Nitrogen (N2) 780,800 (78.080%) 780,848 (78.0848%) 780,818 (78.0818%)

Oxygen (O2) 209,500 (20.950%) 209,390 (20.9390%) 209,435 (20.9435%)

Argon (Ar) 9,340 (0.9340%) 9,332 (0.9332%) 9,332 (0.9332%)

Carbondioxide (CO2) 397.8 (0.03978%) 400 (0.0400%) 385 (0.0385%)

Neon (Ne) 18.18 (0.001818%) 18.2 (0.00182%) 18.2 (0.00182%)

Helium (He) 5.24 (0.000524%) 5.2 (0.00052%) 5.2 (0.00052%)

Methane (CH4) 1.81 (0.000181%) 1.5 (0.00015%) 1.5 (0.00015%)

Krypton (Kr) 1.14 (0.000114%) 1.1 (0.00011%) 1.1 (0.00011%)

Hydrogen (H2) 0.55 (0.000055%) 0.5 (0.00005%) 0.5 (0.00005%)

Nitrous

oxide(N2O) 0.325 (0.0000325%) 0.3 (0.00003%) 0.3 (0.00003%)

Carbon

monoxide(CO) 0.1 (0.00001% ) 0.2 (0.00002%) 0.2 (0.00002%)

Xenon (Xe) 0.09 (0.000009%) 0.1 (0.00001%) 0.1 (0.00001%)

Nitrogen

dioxide(NO2) 0.02 (0.000002%) - - - -

Iodine (I2) 0.01 (0.000001%) - - - -

Ammonia (NH3) trace trace - - - -

Sulphur

dioxide(SO2) trace trace - - - -

Ozone (O3)

0.02 to 0.07

[note 4]

(2 to 7 106%)

[note 4]- - - -

Trace to

30 ppm[note 6]

(----) - - - - 2.9 (0.00029%)

Dry air

total(air) 1,000,065.265 (100.0065265%) 999,997.100 (99.9997100%) 1,000,000.000 (100.0000000%)

Not included in above dry atmosphere:

Water

vapor(H2O) ~0.25% by mass over full atmosphere, locally 0.001%5% by volume.[21]

1. ^Concentration pertains to the troposphere

2. ^The NASA total value do not add up to exactly 100% due to roundoff and uncertainty. To normalize, N2should be

reduced by about 51.46 ppmv and O2by about 13.805 ppmv.

3. ^ppmv: parts per million by volume (note: volume fraction is equal to mole fraction for ideal gas only, see volume

(thermodynamics))

4. ^ abcdefvalues disregarded for the calculation of total dry air

5. ^ ab(O3) concentration up to 0.07 ppmv (7 106%) in summer and up to 0.02 ppmv (2 106%) in winter

6. ^volumetric composition value adjustment factor (sum of all trace gases, below the (CO2), and adjusts for 30 ppmv)

See also
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Air

Density

Atmosphere of Earth

International Standard Atmosphere

U.S.Standard Atmosphere

NRLMSISE-00

Notes

1. ^like the dry air is a mixture of gases his molar mass is a pondered molar mass of their components

References

1. ^ abOlson, Wayne M. (2000) AFFTC-TIH-99-01, Aircraft Performance Flight

2. ^ abICAO, Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)), Doc 7488-CD, Third

Edition, 1993, ISBN 92-9194-004-6.

3. ^ abGrigorie, T.L., Dinca, L., Corcau J-I. and Grigorie, O. (2010) Aircrafts [sic] Altitude Measurement Using Pressure

Information:Barometric Altitude and Density Altitude

4. ^ abA., Picard, R.S., Davis, M., Glser and K., Fujii (CIPM-2007) Revised formula for the density of moist air

5. ^ abcdefS. Herrmann, H.-J. Kretzschmar, and D.P. Gatley (2009), ASHRAE RP-1485 Final Report

6. ^ abF.R. Martins, R.A. Guarnieri e E.B. Pereira, (2007) O aproveitamento da energia elica (The wind energy

resource).

7. ^ abAndrade, R.G., Sediyama, G.C., Batistella, M., Victoria, D.C., da Paz, A.R., Lima, E.P., Nogueira, S.F. (2009)

Mapeamento de parmetros biofsicos e da evapotranspirao no Pantanal usando tcnicas de sensoriamento remoto

8. ^ abMarshall,John and Plumb,R. Alan (2008), Atmosphere, ocean, and climate dynamics: an introductory text ISBN

978-0-12-558691-7.

9. ^ abPollacco, J. A., and B. P. Mohanty (2012), Uncertainties of Water Fluxes in Soil-Vegetation-Atmosphere Transfer

Models: Inverting Surface Soil Moisture and Evapotranspiration Retrieved from Remote Sensing, Vadose Zone Journal,

11(3), doi:10.2136/vzj2011.0167.

10. ^ abShin, Y., B. P. Mohanty, and A.V.M. Ines (2013), Estimating Effective Soil Hydraulic Properties Using Spatially

Distributed Soil Moisture and Evapotranspiration, Vadose Zone Journal, 12(3), doi:10.2136/vzj2012.0094.

11. ^ abSaito, H., J. Simunek, and B. P. Mohanty (2006), Numerical Analysis of Coupled Water, Vapor, and Heat

Transport in the Vadose Zone, Vadose Zone J. 5: 784-800.12. ^ abcdPerry, R.H. and Chilton, C.H., eds., Chemical Engineers Handbook, 5th ed., McGraw-Hill, 1973.

13. ^Shelquist,R (2009) Equations - Air Density and Density Altitude (http://wahiduddin.net/calc/density_altitude.htm)

14. ^Shelquist,R (2009) Algorithms - Schlatter and Baker (http://wahiduddin.net/calc/density_algorithms.htm)

15. ^Partial sources for figures: Base constituents, Nasa earth factsheet

(http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html), (updated 2014-03). Carbon dioxide, NOAA Earth System

Research Laboratory (http://www.esrl.noaa.gov/gmd/ccgg/trends/#mlo), (updated 2014-03). Methane and Nitrous

Oxide, The NOAA Annual greenhouse gas index(AGGI) Greenhouse gas-Figure 2

(http://www.esrl.noaa.gov/gmd/ccgg/aggi.html), (updated 2014-03).

16. ^A.,Picard, R.S., Davis, M., Glser and K., Fujii (2008), Revised formula for the density of moist air (CIPM-2007),

Metrologia 45 (2008) 149155 doi:10.1088/0026-1394/45/2/004, pg 151 Table 1

17. ^S.Herrmann, H.-J. Kretzschmar, and D.P. Gatley (2009), ASHRAE RP-1485 Final Report Thermodynamic Properties

of Real Moist Air,Dry Air, Steam, Water, and Ice pg 16 Table 2.1 and 2.2

18. ^Thomas W. Schlatter (2009), Atmospheric Composition and Vertical Structure pg 15 Table 2
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://www.esrl.noaa.gov/gmd/ccgg/aggi.htmlhttp://www.esrl.noaa.gov/gmd/ccgg/trends/#mlohttp://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.htmlhttp://wahiduddin.net/calc/density_algorithms.htmhttp://wahiduddin.net/calc/density_altitude.htmhttp://en.wikipedia.org/wiki/Special:BookSources/9780125586917http://en.wikipedia.org/wiki/Sichttp://en.wikipedia.org/wiki/Special:BookSources/9291940046http://en.wikipedia.org/wiki/NRLMSISE-00http://en.wikipedia.org/wiki/U.S._Standard_Atmospherehttp://en.wikipedia.org/wiki/International_Standard_Atmospherehttp://en.wikipedia.org/wiki/Atmosphere_of_Earthhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Atmosphere_of_Earth


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http://en.wikipedia.org/wiki/Density of air 8/8

External links

Conversions of density units by Sengpielaudio (http://www.sengpielaudio.com/ConvDensi.htm)

Air density and density altitude calculations and by Richard Shelquist

(http://wahiduddin.net/calc/density_altitude.htm)

Air density calculations by Sengpielaudio (section under Speed of sound in humid air)

(http://www.sengpielaudio.com/calculator-airpressure.htm)

Air density calculator by Engineering design encyclopedia

(http://www.enggcyclopedia.com/calculators/physical-properties/air-density-calculator/)

Atmospheric pressure calculator by wolfdynamics (http://www.wolfdynamics.com/tools/atmospheric-

pressure-calculator.html/)

Air iTools - Air density calculator for mobile by JSyA (https://itunes.apple.com/en/app/air-

itools/id598469643?mt=8)

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Categories:Atmospheric thermodynamics Density

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19. ^ICAO, Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)), Doc 7488-CD, Third

Edition, (1993), ISBN 92-9194-004-6. pg E-x Table B

20. ^U.S. Committee on Extension to the Standard Atmosphere (COESA) (1976) U.S. Standard Atmosphere, 1976 pg 03

Table3

21. ^ abWallace, John M. and Peter V. Hobbs. Atmospheric Science;An Introductory Survey.Elsevier. Second Edition,

2006. ISBN 13:978-0-12-732951-2. Chapter 1
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Documents

Density of Air - Wikipedia, The Free Encyclopedia