the stabilised arc discharge region of the voltage-current characteristic of a gas discharge tube
What can not be read from the
characteristic is that the
nature of the arc discharge is
also influenced by
temperature. At higher
temperatures more electrons
will be freed, resulting in more
and more violent collisions
which in turn will free more
electrons. Due to this process
it can take one or even a few
minutes before the behaviour
of the arc discharge stabilises
at a constant working
temperature. To prevent the
arc discharge from falling back
into a glow discharge under
the fluctuation of external
conditions, the supply voltage
has to be increased until and
limited to point H of the
characteristic. A further increase of the operation point beyond H, will eventually
overload and destroy the electrodes and/or the housing of the device, due to
extremely high currents and/or temperatures.