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Homework Help: Calculating air density from a barometer?

  1. Oct 3, 2011 #1
    1. The problem statement, all variables and given/known data

    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?

    2. Relevant 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)

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

    3. 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.
    Last edited: Oct 3, 2011
  2. jcsd
  3. Oct 5, 2011 #2
    I think there might be correction factors for humidity and altitude which might be in mm of Hg?
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