This procedure is used to measure the volume of a
pressure vessel. Because pressure vessels can stretch while pressurised the
volume also changes. The change in volume is important for
design purposes and estimating the expected altitude.
Due to pressures involved, this experiment should be carried
out behind a safety barrier.
Air source. This includes pumps, tanks, compressors etc.
This procedure measures the volume of an unpressurised
pressure vessel. The labelled value on a bottle is not the exact
Place the pressure vessel on the scale, and zero the
Completely fill the bottle with water.
Record the reading on the scale. (1 gram = 1 mL).
Procedure B - Pressurised
This procedure describes how to measure the increase in
volume of a pressure vessel as it stretches under pressure. This
information can be used when simulating the flight of the
rocket. The description below is for a PET bottle, but is
equally applicable to other pressure vessels.
Fill the bottle with water all the way to
the neck and stand bottle vertically.
Mark a line on the bottle representing the meniscus.
Connect air supply to pressure vessel. NOTE: You should have performed the
burst test on
the bottle prior to this test in order to not exceed the
Slowly increase the pressurise to the desired
Mark a line on the bottle representing the new
meniscus level. NOTE: Because this
step requires you to approach the pressurised bottle, appropriate protection should be worn
Depressurise the bottle.
When the bottle is depressurised empty enough water
until the meniscus lines up with the pressurised mark.
Place the bottle with water on the scale.
Zero the scale.
Add water to the bottle until it reaches the
Take the reading on the scale. This represents the
volume increase of the bottle at the particular
Caution should be exercised when performing this
experiment. Alternatively one can place a scale on the side
of the bottle and record the change in meniscus levels