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Servicing
Photomultiplier Tube Replacement
9. Re-install the measurement bench. Refer to “Removing the
Measurement Bench and Lowering the Partition Panel” in this chapter.
Photomultiplier Tube
Replacement
Use the following procedure to replace the PMT tube.
Equipment Required:
Photomultiplier tube and PMT base
Nut driver, 5/16-inch
Flat blade screwdriver
Philips screwdriver, small
Equipment Damage Some internal components can be damaged by small
amounts of static electricity. A properly grounded antistatic wrist strap
must be worn while handling any internal component. ▲
1. Turn instrument OFF, unplug the power cord, and remove the cover.
2. Disconnect the high voltage cable from the PMT power supply and
unplug the BNC cable from the Input Board.
3. Remove six external screws holding PMT cover plate and the four
screws holding the PMT shroud to the panel and remove the PMT
cover plate (Figure 7–9). If the cooler fan is attached, unplug the fan
power cord if necessary.
PMT Cover Plate Screws (6)
PMT Shroud Screws (4)
PMT Base Screws (3)
PMT Base Assembly
Figure 7–9. Replacing the PMT
Thermo Fisher Scientific
Model 17i Instruction Manual
7-19