Instability Of The Ion Source With A High Life Time And Low Kv Setting; Exchanging Fuses - Leica EM TIC 3X Operating Manual

5.6.2.10 Instability of the ion source with a high life time and low kV setting.

Due to the nature of the saddle field ion gun type the material of the cathodes is
permanently removed. This material removal changes the electrical field
characteristic and can cause instable ionisation inside the gun at a life time higher
than ~100 hrs and low voltages between 1 and 4 kV using the default value of the
current. If instabilities are noticeable please adapt the current manually in steps of
0.2 mA as long as stable ionisation can take place.
For example: stability of 3 kV (default 1 mA) can be achieved by manual adaption of
the current to 3 mA.
Since the adaption of the current is related to the current between anode and
cathode the ion current will be not influence. Hence, sample temperature will
not increase.

5.6.3 Exchanging fuses

If a fuse needs to be replaced (fuse faulty) (particularly if it fails repeatedly), try
to discover the reason for the failure of the fuse. If necessary, contact the
Service department.
There is danger if wrong fuses are installed.
This may cause personal injury due to electric shock and damage to the
system.
Only fuses with the appropriate rating must be used.
Exchanging the main fuse
1. Switch off the system at the main switch and remove the power cable.
2. Use a screwdriver to release the main fuse from its holder, as shown in the
illustration.
3. Remove the main fuse and replace it with a new one.
Page 95 Leica EM TIC 3X Operating Manual 07/17