2 Stativschiene
3 Proberohre
4 Rollachse mit Zeigern
5 Skala
1. Sicherheitshinweise
• Gerät vorsichtig behandeln, Glasröhre ist zer-
brechlich.
• Röhren nach den Versuchen erst abkühlen
lassen. Material speichert die Wärme. Verbrennungsgefahr!
2. Beschreibung
Das Längenausdehnungsgerät dient zur gleichzeitigen Messung und zum Vergleich der thermischen
Längenausdehnungskoeffizienten röhrenförmiger
Körper verschiedener Materialien.
Auf einer Aluminiumschiene sind drei Proberohre
in einem Dampfverteiler fest gelagert. Die freie
Ende jeden Rohrs liegt beweglich auf einer Rollachse. Die Anzeige der Längenausdehnung der Rohre
erfolgt durch drei unterschiedlich farbige Zeiger
auf einer Spiegelskala.
• Danger of serious burns! It is a property of all
the materials that these tubes are made of that
they store heat. Therefore, allow the tubes to
cool after every experiment.
2. Description
The thermal expansion apparatus is used for the
simultaneous measurement and comparison of the
coefficient of thermal expansion of tubular bodies
made of different materials.
Three sample tubes are mounted on an aluminium
base strip. The free end of each tube rests on a
pilot bearing. The thermal expansion of the tubes
is demonstrated by three pointers, each of a different colour, on a mirror scale.
Dimensions: 830 x 80 x 70 mm
Weight: 1200 g approx.
Sample tubes: Brass, aluminium, glass
Dimensions: 700 mm x 6 mm Ø
Tube length: 600 mm
4. Operation
In order to perform the experiment, the following
equipment is additionally required:
1 Steam generator 8624700
• Mount the mirror scale onto the base strip.
• Clamp the pointers below the tubes so as to
facilitate the measurement of thermal expansion.
• Calibrate all pointers to zero.
1
∆
⋅
∆
• Fill half of the steam generator with water,
place it onto the hot plate, insert the cork
cover and fasten it shut with the securing
clamp.
•Connect the thermal expansion apparatus to
the steam generator with a hose.
• Place a dish below the sample tube ends in
order to collect condensed water.
• Measure the room temperature T.
• Switch on the hot plate.
• Allow the steam to flow for some time through
the sample tubes. This should continue till the
tubes have attained a temperature equal to
the boiling point of water (100°C). Observe the
respective pointer deflections
•Read the thermal expansion l off the scale
(1 mm thermal expansion corresponds to 4 cm
pointer deflection on the scale).
•Calculate the temperature difference T in
relation to the room temperature.
The coefficient of linear thermal expansion of
different materials can be determined by the formula:
l
=α
Tl
where l is the length of the tube measured from its
fixed bearing up to the pilot