Instruction Sheet - 3B SCIENTIFIC PHYSICS U18570 Instrucciones De Uso

3B SCIENTIFIC ® PHYSICS

Instruction sheet

05/08 ALF
1. Safety instructions
Hot cathode tubes are thin-walled, highly evacuated
glass tubes. Treat them carefully as there is a risk of
implosion.
•
Do not subject the tube to mechanical stresses.
If voltage or current is too high or the cathode is at
the wrong temperature, it can lead to the tube be-
coming destroyed.
•
Do not exceed the stated operating parameters.
When the tube is in operation, the terminals of the
tube may be at high voltages with which it is dan-
gerous to come into contact.
•
Only use safety experiment leads for connecting
circuits.
•
Only change circuits with power supply
switched off.
•
Only exchange tubes with power supply
switched off.
When the tube is in operation, the stock of the tube
may get hot.
•
Allow the tube to cool before dismantling.
The tube may only be used with tube holder S
(U185001).
Dual Beam Tube S U18570
1
1 Guide pin
2 Connection pins
3 Axial electron gun
4 Perpendicular electron gun
5 Deflector plate
6 Fluorescent screen
The compliance with the EC directive on electro-
magnetic compatibility is only guaranteed when
using the recommended power supplies.
2. Description
The dual beam tube can be used to determine the
specific charge e/m from the diameter of the path
followed by electrons fired into the tube from a
perpendicularly mounted gun with a vertically a-
ligned magnetic field and observation of the spiral
path followed by electrons fired axially into a co-
axial magnetic field.
The dual beam tube is a partly evacuated electron
tube, filled with helium at low pressure and
equipped with both axial and perpendicular elec-
tron guns. The electron beams are perpendicular to
one another and a common deflector plate is pro-
vided for both guns. The electron beam source is an
oxide cathode heated indirectly via a heating coil.
The electron paths show up as a fine, slightly green-
ish beam due to impact excitation of the helium
atoms.