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
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)