Air Density Calculator

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Steps For Calculating The Density of Air

1. Saturation Vapor Pressure

Using the Wobus polynomial formula:

Es = Eso / p8

Where p = c0 + T (c1 + T (c2 + T (c3 + T (c4 + T (c5 + T (c6 + T (c7 + T (c8 + T (c9))))))))

  • Es is the saturation pressure of water vapor (hPa)
  • eso = 6.1078
  • T is the air temperature in degrees Celsius
  • c0 = 0.99999683
  • c1 = -0.90826951 × 10-2
  • c2 = 0.78736169 × 10-4
  • c3 = -0.61117958 × 10-6
  • c4 = 0.43884187 × 10-8
  • c5 = -0.29883885 × 10-10
  • c6 = 0.21874425 × 10-12
  • c7 = -0.17892321 × 10-14
  • c8 = 0.11112018 × 10-16
  • c9 = -0.30994571 × 10-19

2. Actual Vapor Pressure

pv = Es × Relative humidity

3. Dry Air Pressure

pd = ptotal - pv

4. Final Air Density

Air density formula

Where:

  • ρair = Density (kg/m³)
  • pd = Partial pressure of dry air (Pa)
  • pv = Pressure of water vapor (Pa)
  • T = Temperature in Kelvins
  • Rd Specific gas constant for dry air = 287.058 J/(kg·K)
  • Rv Specific gas constant for water vapour = 461.495 J/(kg·K)