Components of the Filament Replacement Kit
Figure 1
Replacement Kit
WARNING
Turn OFF and disconnect power to the VQM
®
Controller before
beginning this filament replacement procedure.
CAUTION
1. The components of the MS Gauge are fragile. Be especially
careful when disassembling and reassembling the gauge.
2. Do NOT scratch the ConFlat knife edge on the gauge.
3. The components of the filament replacement kit are UHV
compatible − perform the replacement procedure in a proper
cleanroom environment.
NOTE: The filament replacement kit includes a custom pair of
tweezers that are notched to grasp the retaining ring.
Tweezers to grasp the
retaining ring
Copper
Gasket
Filament
Assembly
Plasma
Screen
Retaining
Ring
Filament Replacement Instructions
NOTE:
Use clean, vacuum component compatible gloves while replacing the
filament.
1. Turn OFF power to the VQM System and vent the vacuum chamber to
atmosphere. Disconnect the cable from the MS Gauge and remove the 6
bolts that attach the MS Gauge to the vacuum chamber. See Figure 2.
Figure 2
Remove the MS Gauge from the Vacuum Chamber
2. Look closely at the port of the MS Gauge and make note of the position of
the components as shown in Figure 3. Orient the gauge as shown in
Figure 3.
CAUTION
Be sure to read through and understand the scope of this procedure
before beginning.
Figure 3
MS Gauge Components - Viewed from the Port End of the Gauge
3. Remove the retaining ring. Use the tweezers provided in the kit to squeeze
the tabs together and carefully lift the retaining ring from the gauge.
Be
careful not to scratch the ConFlat knife edge when removing the retaining
ring
.
4. Remove the plasma screen.
Figure 4
Retaining Ring and Plasma Screen Removed
Retaining Ring
Plasma Screen
Alignment Pin
See Figure 5
Filament Latch
See Figure 5
NOTE:
The filament
assembly is under the
plasma screen.
5. Use tweezers or small needle nose pliers to rotate the latch
counterclockwise and unlatch the filament assembly so it can be removed
from the gauge. Do not use excessive force when unlocking or locking the
filament latch.
Figure 5
Filament Assembly Latch
6. Use tweezers or small needle nose pliers to carefully lift the filament
assembly from the gauge. Note the position of the alignment pin and the
center pin (latch pin). Also note the position of the filament (which is near
the alignment pin hole in the ceramic disk) and the filament port which is
in the gauge assembly. Figure 6.
Figure 6
Position of the Filament and Alignment Pins
Filament Latch
Locked (Closed)
Filament Latch
Unlocked (Open)
Filament Assembly
Alignment Pin
Latch Pin
Filament
Assembly
Latch
Latch Pin
Alignment Pin
Filament
Ceramic Disk
NOTE:
The Filament
Assembly is
shown upside
down in this
illustration.
1
2
3
4
