3B Scientific Teltron Triode D, Helium-filled - Manual

3B SCIENTIFIC ® PHYSICS
1
Gas Triode D 1000653
Instruction sheet
12/12 ALF
1 2
3 4
5
6 8
-
7
1 Boss
2 4-mm plug for connect-
ing anode
3 Anode
4 Grid
5 Boss with 4-mm plug for
connecting grid
6 Heater filament
7 Cathode plate
8 4-mm sockets for heater
filament and cathode
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.
• Do not subject the connection leads to any
tension.
• The tube may only be used with tube holder
D (1008507).
If voltage or current is too high or the cathode is
at the wrong temperature, it can lead to the tube
becoming destroyed.
• Do not exceed the stated operating parame-
ters.
When the tube is in operation, the terminals of
the tube may be at high voltages with which it is
dangerous to come into contact.
• Only change circuits with power supply
equipment switched off.
• Only exchange tubes with power supply
equipment switched off.
When the tube is in operation, the stock of the
tube may get hot.
• Allow the tube to cool before dismantling.
Use of the equipment over long periods and
involving hefty gas discharges can cause loss of
material from the electrodes, which is deposited
on the glass of the tube itself resulting in darken-
ing of the surface.
The compliance with the EC directive on elec-
tromagnetic compatibility is only guaranteed
when using the recommended power supplies.
2. Description
The gas triode allows recording of the I
A
– U
A
characteristic of a thyratron, observation of ex-
cited and non-excited discharge and of the dis-
continuous transfer of energy by helium atoms
in inelastic collision with free electrons.
The gas triode is a helium-filled tube with a pure
tungsten heater filament (cathode) and a round
metal plate (anode) with a wire grid between
them, all inside a clear glass bulb. The cathode,
anode and grid are all aligned parallel to one
another. This planar configuration corresponds
to the conventional symbol for a triode. A circu-
lar metal plate attached as a backing to the fila-
ment ensures that the electric field between the
anode and cathode is uniform.