1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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)

    Hence:
    δ=p_ambient/(1.225 kgm^(-3) )= and θ=T_ambient/(288 K) =
    Thus:
    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.
    Thanks
     
    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?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Calculating air density from a barometer?
Loading...