Thermo Electron 48C, Instruction Manual

Page: 128 / 204

Chapter 7 Servicing
7-8
PREAMPLIFIER/DETECTOR ASSEMBLY REPLACEMENT
Equipment required:
Detector Assembly (Part No. 8938), (Preamplifier Board - Part No. 7363)
Screwdriver
1. Wear an antistatic wrist strap, see “Safety Precautions,” earlier in this chapter for
more information.
2. Disconnect power and remove cover.
3. Disconnect the cables between the preamplifier and IR Source, Bias Power Supply
Board, and Input Signal Conditioning Board.
4. Remove the four screws holding the preamplifier cover to the preamplifier assembly
and remove the cover.
5. Remove the screws holding the preamplifier/detector assembly to the optical bench.
Note access holes through the preamplifier printed circuit board. Carefully remove
the preamplifier/detector assembly from the optical bench.
6. Install the new preamplifier/detector assembly by following the above directions in
reverse.
7. Re-install the instrument cover.
PUMP REBUILDING
Equipment required:
Screwdriver
Pump Rebuild Kit (Flapper Valve and Diaphragm) (Part No. 8606 KNF)
1. Wear an antistatic wrist strap, see “Safety Precautions,” earlier in this chapter for
more information.
2. Disconnect power and remove cover.
3. Loosen the fittings and remove both lines going to the pump.
4. Remove the four screws from the top plate, remove top plate, flapper valve, and the
bottom plate.
5. Remove the screw holding diaphragm onto piston, remove diaphragm.
6. Assemble the pump by following the above procedure in reverse, make sure the
Teflon
®
(white) side of the diaphragm is facing up and that the flapper valves cover
the holes of the top and bottom plate.
7. Re-install the instrument cover.
8. Perform a leak test as described in Chapter 5, “Preventive Maintenance.”