3B Scientific Teltron Discharge Tube S User Manual
Page 3
A TELTRON Product from UK3B Scientific Ltd. ▪ Suite 1 Formal House, Oldmixon Crescent ▪ Weston-super-Mare
Somerset BS24 9AY ▪ Tel 0044 (0)1934 425333 ▪ Fax 0044 (0)1934 425334 ▪ e-mail [email protected]
Technical amendments are possible
© Copyright 2012 3B Scientific GmbH
5.2 Experiment instructions
To perform experiments using the gas discharge
tube S, the following equipment is also required:
1 Tube holder S
1014525
1 Rotary-vane vacuum pump, two-stage
1003317
2 Experiment lead, safety plug and socket
1002839
1 High voltage power supply, 5 kV (230 V, 50/60 Hz)
1003310
or
1 High voltage power supply, 5 kV (115 V, 50/60 Hz)
1003309
•
Connect the hose to the vacuum pump.
•
Connect the power supply to the 4-mm ter-
minal pins.
•
Apply a voltage of 5 kV to demonstrate lumi-
nescent discharges.
•
After the operating voltage is applied, evacuate
the tube and close the vent valve.
•
Darken the room and observe the luminescent
phenomena.
•
When the experiment is finished, turn off the
pump and open the vent valve to let air into the
discharge tube.
Gas discharge at low pressure
Depending on the range of pressure, various phe-
nomena may be observed when high voltage is
applied:
Pressure range
Phenomena
1013 mbar
No discharge
30 – 10 mbar
Threads of light between
cathode and anode
10 – 1 mbar
Dark space in front of the
cathode
1 – 10
-1
mbar
Discharging in layers
10
-1
– 10
-2
mbar
Glowing light
10
-2
mbar
Anode rays and cathode rays,
(images of respective slits on
fluorescent screens)
Gas discharges with various gases
•
Allow a sequence of different gases into the
tubes.
The luminescent phenomena will differ depending
on the gas used.
•
Use a spectroscope to view spectral lines.
Magnetic deflection of anode rays and cath-
ode rays
•
At pressures below 10
-2
millibars, move a per-
manent magnet towards the tube and observe
how it deflects the rays.
Due to the differing masses of the particles in-
volved, the image of the slit on the fluorescent
screen does not move much for the anode rays, but
the cathode rays are deflected heavily