Calculating air density from a barometer?

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SUMMARY

The discussion centers on calculating air density using barometric pressure and temperature data. The ambient temperature is 19°C, with a barometric pressure of 765 mm Hg. Two correction factors, 2.35 and 2.41, are mentioned, but their application remains unclear. The relevant equations include the ideal gas law and the relationships for density and temperature adjustments, specifically using the standard conditions of ρ_sls = 1.225 kg/m³ and T_sls = 288 K.

PREREQUISITES
  • Understanding of the ideal gas law and its application in calculating density.
  • Knowledge of barometric pressure conversion (1 mm Hg = 133 Pa).
  • Familiarity with standard atmospheric conditions (ρ_sls and T_sls).
  • Basic concepts of correction factors in scientific measurements.
NEXT STEPS
  • Research the application of correction factors in atmospheric science.
  • Learn about the impact of humidity on air density calculations.
  • Study the effects of altitude on barometric pressure and air density.
  • Explore the derivation and application of the ideal gas law in real-world scenarios.
USEFUL FOR

Students in physics or environmental science, meteorologists, and anyone involved in atmospheric studies or lab reports requiring air density calculations.

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Homework Statement



Working on a lab report, where we are asked to calculate the density of air.

Ambient Temperature: 19°C
Barometer (mm Hg abs): 765
There were two correction factors: 2.35 and 2.41

How do I use the above information to find the Air Density (kg/m3) ?
What are the correction factors? And, why did we take two correction factors?

Homework Equations


I know that: 1mm Hg = 133 Pa; and μ=1.8*10^-5 Nsm^-2

σ=δ/θ where δ=p_ambient/p_sls and θ=T_ambient/T_sls
We know that:
ρ_sls=1.225 kgm^(-3)
p_sls=760 mm Hg abs
T_sls=288 K (15°C)

Hence:
δ=p_ambient/(1.225 kgm^(-3) )= and θ=T_ambient/(288 K) =
Thus:
σ=δ/θ= δ/θ=

The Attempt at a Solution



Using ρ=p/(RT)

where T=292.15 K, R=0.287, p=101,745 Pa

But I just don't know how to use the correction factors. Should I take an average of both of them? Should I have two air densities?
Any help you make have would be much appreciated.
Thanks
 
Last edited:
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I think there might be correction factors for humidity and altitude which might be in mm of Hg?
 

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