1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

The proportion of Hydrogen to limit errors in measurement.

  1. May 14, 2013 #1
    It is proposed to use a katharometer to mesaure the amount (about 5%) of oxygen in nitrogen, in the presence of a small amount (0.5%) hydrogen. How constant would the proportion of hydrogen have to be in order to limit errors in measurement of % oxygen to +/- 0.1%?

    The thermal conductivities are:
    Nitrogen 0.993
    Oxygen 1.052
    Hydrogen 6.993

    Not to sure where to start with this one, any guidance just to start me off would be most appreciated.
  2. jcsd
  3. May 15, 2013 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    An approximation of the mixture's thermal conductivity can be expressed as the mole fraction-weighted sum of the individual components. For example,

    λm = χ1λ1 + χ2λ2 +… χnλn
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted