Thermo Scientific DSQ II, Hardware Manual

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2
Maintaining the DSQ II
Replacing the Electron Multiplier
Thermo Scientific DSQ II Hardware Manual 59
18. Reattach the vacuum manifold cover.
19. Reattach the front and top covers.
20. Restart the DSQ II.
Replacing the Electron Multiplier
The electron multiplier consists of a conversion dynode and cathode. It must be kept clean
and free of dust because even the smallest amount of lint can cause spectral noise or static
discharge, which could lead to power supply failure. Always clean the conversion dynode and
electron multiplier with clean dry gas, never liquids or abrasives, each time you remove the
vacuum manifold cover. Attach the vacuum manifold cover when you temporarily step away
from the instrument to prevent dust from accidentally contaminating the system.
You may need to replace the electron multiplier if AutoTune is consistently setting the voltage
to 1800 V or higher. To replace the electron multiplier, you will need:
• Cathode (PN A0022-14633)
• Forceps
• Gloves, clean, lint- and powder-free
• Lint-free cloth
• Screwdriver, Flat
• Screwdriver, Phillips #1
• Wrench, Allen, 2.5 mm
• Wrench, Allen, 3 mm
1. Cover the work area with a lint-free cloth.
2. Shut down and vent the DSQ II, as described in "Shutting Down the GC/MS System"
on page 18 .
3. Remove the front and left covers, as described in " Removing the Front and Top Covers"
on page 25 and " Removing the Left Cover" on page 29
4. Remove the vacuum manifold cover, as described in " Removing the Vacuum Manifold
Cover" on page 32 .
CAUTION - INSTRUMENT DAMAGE. If you notice an ion burn on the surface of the
conversion dynode, clean it with Alox/water. Normally, it will not adversely affect the
performance of the instrument.
WARNING - ELECTRICAL SHOCK HAZARD. Before proceeding. unplug the DSQ II to
avoid an electrical shock.
Note Wear clean, lint- and powder-free gloves when you handle any vacuum manifold
components.