3B Scientific Oscillation Tube - Manual (Page 3)

6
General notes:
The accuracy of the measurements depends strongly
upon the following factors:
• The precision tube must be extremely clean. If neces-
sary, clean the tube with tissue paper.
• The aluminium cylinder must also be extremely clean.
The slightest amount of dirt such as grease from fin-
gers can lead to considerable friction. Therefore the
cylinder should be cleaned before each measurement
using a fluff-free cloth and some petroleum ether.
• The slightest deformation of the cylinder (e.g. due to
having been dropped) adversely affects the experi-
ment.
• The glass tube must be vertical.
• All stoppers must be airtight.
• Since the duration of the oscillation is squared in the
equation, the time does need to be measured as ac-
curately as possible.
5. Measurement example
Volume V: 10400 cm³
Mass of cylinder m: 15.2 g
Ø
inner
of tube d: 16 mm
Atmospheric pressure p
L
: 1018 mbar
Time t in seconds for five oscillations:
5.172
5.276
5.259
5.224
5.305
5.175
5.231
5.241
5.191
5.175
———
Total: 52.249
Average: 5.2249
Period of oscillation T
s
: 1.04498 s
Substituting into equation (11) gives:
? = 1.39
From published tables:
? = 1.40
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com • Technical amendments are possible