DATREND Systems venTest, Руководство по эксплуатации

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venTest OPERATORS MANUAL
2 Volume measuring of Gases
Measuring of air volume is not easy because gases are unlike liquids, being compressible, and
expand when being warmed up.
If you state a gas volume, you also have to state the respective ambient conditions of pressure
(e.g. 1013 mbar) and temperature (e.g. 20°C). With the gas law below described it is possible to
convert into different ambient conditions.
2.1 Physical Basics (Ideal Gas)
• Gases do not have a fixed volume, but a fixed mass which is dependent on the amount
of gas molecules and their mass.
• An amount of gas always takes up the volume at their disposal and in doing so a
pressure is created.
Example: Assume a closed receptacle filled with air, showing a
volume of 1 l and a pressure of 1 bar. If volume is reduced to 0.5 l,
pressure in the recipient will increase to 2 bar. If the original volume
is increased to 2 l, pressure will decrease to 0.5 bar.
Example: Assume a closed recipient filled with air with a flexible
wall; volume 1 l, ambient pressure 1bar. If ambient pressure is
increased to 2 bar, volume will decrease to 0.5 l. If ambient pressure
is reduced to 0.5 bar volume will increase to 2 l.
Appendix A
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