Servicing
Filter Wheel Replacement
Thermo Fisher Scientific
Model 48
i
Instruction Manual
7-13
1.
Turn the instrument OFF, unplug the power cord, and remove the
cover.
2.
Remove the chopper motor and wheel assembly by removing the three
motor plate Allen screws holding the motor plate to the optical bench
(
Figure 7–6
).
Figure 7–6.
Removing the Motor
3.
Remove the cross recessed screw on the bottom of the motor plate.
4.
Insert the 5/64-inch Allen wrench through the access hole in the
bottom of the motor plate, loosen the set screw holding the filter wheel
to the motor shaft, and
carefully
pry the filter wheel off the motor shaft
(
Figure 7–5
).
5.
Install new filter wheel by following the previous steps in reverse. Make
sure that the set screw seats on the flat of the motor shaft.
6.
After the filter wheel is installed, spin the wheel and observe that it runs
true on the motor shaft.
7.
Let the instrument sample zero air for about 90 minutes.
8.
From the Main Menu, choose Service >
Initial S/R Ratio
.
The Initial S/R Ratio screen appears.
Motor Mount Screws (4)
Motor Plate Screws (3)
Motor Motor Plate
