3B Scientific Pressure Container for Determining Weight of Air User Manual

3B SCIENTIFIC® PHYSICS

Pressure capsule for determining weight of air

8412150

Instruction sheet

02/06 ALF

1 Inlet valve
2 Pressure capsule
3 Outlet valve
4 Hose

1. Description

The pressure capsule is designed for demon­strating the weight of air and determining its
density by means of comprerssion.

It is a metal capsule with a cycle valve so
that air can be pumped in and an outlet valve
at the other end.

2. Technical data

Dimension: 190 mm x 60 mm Ø
Mass: 100 g approx.

3. Operation

The following additional equipment is re­quired to complete the experiment:

1 Compressed air pump 8411210
1 Electronic scales U42048
1 500 ml measuring cylinder
1 Glass tube

1 Glass tubing, right angled
2 Rubber stoppers with hole
1 Rubber stopper without hole
1 Stand base 8611160
1 Universal clamp U13261
1 Universal sleeve U13255
1 Stand rod U15011

• Mass m
ing scales before starting the experiment.

• Fill the pressure capsule with air, pump­ing the piston 5-7 times.

• Mass m
has been filled.

• The difference m
of the air that has been pumped in.

• Set up an experiment as in Fig. 1 to de­termine the volume of air.

• Close the glass test tube by means of a
rubber stopper with a right-angled length
of glass tubing passed through its hole.

• Plug the other end of the glass tube with
the other stopper and connect a hose to
the capsule through it.

weigh the pressure capsule us-

1

weigh the capsule again after it

2

– m1 gives the mass m

2

1

• Completely fill the glass tube with water.

• Close the end of the right-angled tubing

using a stopper with no hole in it.

• Clamp the glass tube to the stand at a
slight angle and adjust the height so that
the tube points into a measuring cylinder
placed beneath it.

• Take the bung out of the right-angle tube
and let any excess water drain out of it so
that the water level only comes up as far
as the bend. Empty this water out of the
measuring cylinder.

• Slowly open the outlet valve until all the
air has escaped from the capsule.

• The escaping air forces water out of the
glass tube. You should collect this water
in the measuring cylinder and measure its
volume.

The water so collected has the same volume
V as the air that has escaped from the cap­sule.

• Use the values you have obtained to cal­culate the density of air using the formula

m

=ρ

V

Perform the experiment several timesto

obtain an average value for ρ.

• From the value of ρ you have measured,
make corrections to extrapolate its value
for standard atmospheric conditions (0°C
and 1013.3 mbars pressure). For this you
will need to measure the room tempera­ture and the air pressure extant at the
time the experiment is being performed.

Fig. 1 Measuring the volume of the escaped air

Elwe Didactic GmbH ▪ Steinfelsstr. 6 ▪ 08248 Klingenthal ▪ Germany ▪ www.elwedidactic.com

3B Scientific GmbH ▪ Rudorffweg 8 ▪ 21031 Hamburg ▪ Germany ▪ www.3bscientific.com

Rights to amend technical specification reservedn