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Pressure rise in a vaccum system gas specific?

  1. Aug 26, 2014 #1
    If I introduce a gas into closed vacuum system at a known rate lets say 10 SCCM there will be a subsequent pressure rise over time. Is that pressure rise gas species dependent. If I evacuate the system and introduce a different gas at 10 SCCM should I see the same rate of pressure rise?

    Im trying to calibrate some flow controllers with respect to each other and I want to be sure my basic understanding is correct.

  2. jcsd
  3. Aug 27, 2014 #2
    No, you will not necessarily see the same pressure rise. A given volume of a gas "A" does not necessarily cause the same increase in pressure as another volume of gas "B". This is because the average molecular mass of each gas species are different. This means that the average absolute momentum (ignoring vector direction) of the particles is different for a given volume and temperature across various species.
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