Figure 7-7. Replacing The Pmt - Thermo Scientific 42i Instruction Manual

Servicing
PMT High Voltage Power Supply Replacement
PMT High Voltage
Power Supply
Replacement
7-14 Model 42i Instruction Manual
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
power cord if necessary.
Figure 7–7. Replacing the PMT
4. Remove the three retaining screws holding PMT base assembly to the
cooler using a 5/16-inch nut driver.
Equipment Damage Do not point the photomultiplier tube at a light
source. This can permanently damage the tube.
5. Pull the PMT and PMT base from cooler assembly by twisting it
slightly back and forth.
6. To install PMT, follow previous steps in reverse making sure to backfill
the cooler with dry air or nitrogen prior to replacing the PMT.
7. Perform a photomultiplier tube calibration. See
Adjustment" in the "Operation" chapter.
Use the following procedure to replace the PMT high voltage power supply
(Figure 7–8).
Equipment Required:
PMT high voltage power supply
7–7). If the cooler fan is attached, unplug the fan
PMT Cover Plate Screws (6)
PMT Shroud Screws (4)
PMT Base Screws (3)
PMT Base Assembly
▲
"PMT Voltage
Thermo Fisher Scientific