Ulvac EGL-206M Instruction Manual page 55

Trouble symptom
18. The emission current is
saturated and cannot be
increased.
Possible cause
A. Poor contact of the filament cable
or filament lead.
B. Saturated emission current due to
low setting of the high voltage.
C. Incorrect dimensions of the emitter
assembly
D. Pressure in the vacuum chamber is
high.
SECTION 7
a. Check if the filament setscrew is tight.
b. Check if the filament support is clean.
If contaminated, clean it by rubbing.
c. Check if the filament cable terminal is tight.
If loose, retighten it.
d. Check if the screw on the atm. side of the high voltage
feed-through terminal is tight.
a. Operate the electron beam gun within its correct range.
0.8 A max. at 10 kV
0.8 A max. at
0.6 A max. at
0.4 A max. at
a. Check dimensions against Figure 5-1.
a. Operate at a pressure below 5 10
45
Corrective action
8 kV
6 kV
4 kV
-2
Pa.