6 - 5
Transpector MPH Operating Manual
6.5.2 How to Determine if a Filament Kit Replacement is Required
Follow these steps to determine if a filament replacement is required. Remember
that Transpector MPH has dual filaments, so if one filament is blown, but the
second filament is intact, Transpector MPH can still be used with the second
filament.
NOTE:
Performance of the second filament may be impacted by previous use of
Transpector MPH.
1
Measure the resistance of each filament. This can be accomplished while the
sensor is under vacuum by measuring the resistance between pins
3
and
10
for filament 1 and pins
4
and
10
for filament 2 (see
). A
failed filament will measure open while an intact filament will measure 0.8
Figure 6-1 Sensor pinout
Table 6-2 Pin assignment
Pin
Assignment
Pin
Assignment
1
PP
8
GND
2
EM HV
9
RF+
3
Filament 1
10 Filament Common
4
Filament 2
11
Reserved
5
Anode
12
Focus
6
RF-
13
TP
7
GND
1
2
3
4
5
6
7
8
9
10
11
12
13