Variations with temperature

Discussion in 'General Airgun Chat' started by Archer50, Jan 4, 2019.

  1. EV2UK

    EV2UK Active Member

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    Not read the whole thread but had a thought pop into my head.

    Pressure will. Increase with heat?
    If a cylinder has a set amount of air in it, the pressure will rise with temperature but the amount of air will remain the same?

    Will this mean that the regulator will shut off at the same pressure BUT will contain less air?
     
  2. frank

    frank Reactive Member

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    When the temperature increases the air expands causing the pressure to rise because the air is contained, the reverse happens when the temperature decreases, the density of the air changes, ie the air molecules get further apart as the temperature increases so the volume increases,
    your regulator will shut off at the same pressure and will contain the same volume of air but at a lower density,
    the lower density allows the air to pass more easily through the transfer port usually increasing the power of the gun,
    imagine a tub of butter straight out of the fridge it is hard to spread but spreads easily once it warms up
     
  3. Welsh Wizard

    Welsh Wizard FT: You Give, You take! Staff Member

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    I do, every month in Shooting sports!!
     
  4. Jesim1

    Jesim1 Active Member

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    The "super testing" is more about curiosity and the desire for knowledge and understanding, which in turn can lead to a better set up or practise by avoiding pitfalls, but I admit this can get too anal for real life use at times.:eek:

    You can see it being helpful on others though: -

    You turn up at a shoot on a cold and frosty morning, you get your gun out of your nice warm car which is 23 degrees. You zero your gun in 3 shots just out of the bag and then wait for an hour and get a coffee as things get sorted - your now on the course an hour after you arrived with a gun which has dropped 30fps or more since zero. The issue is not being able to sort this, the issue is not knowing on the first shot it has happened? It's also a bitch if you set your gun to 11.8fpe in the cold and have a range official check it on a warm day at 12.5fpe:oops:

    James
     

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