1

Shutdown the system and stop the gas supply for detectors.

2

Loosen the knurled screw and remove the FPD cover.

3

Loosen the 2 photomultiplier unit fixing knurled screws.

4

Slowly pull the photomultiplier unit out to remove it.

5

Remove the 2 setscrews of the photomultiplier socket.

6

Detach the photomultiplier socket fixing plate.

7

Hold the photomultiplier socket and pull the photomultiplier out slowly.

8

Holding the base of the photomultiplier, pull it out slowly from the socket.

Replace the O-ring of the socket if it has deteriorated.

Photomultiplier socket O-ring 036-11031

9

Check that the O-ring in the opening (the filter attachment unit) of the photomultiplier case has not deteriorated.

Replace it if it has deteriorated.

O-ring for the photomultiplier opening 036-11018

10

Insert the new photomultiplier into the socket.

Photomultiplier P/N 221-48578

11

Insert the photomultiplier slowly into the photomultiplier case.

12

Attach the photomultiplier socket fixing plate and fix in place using the 2 screws.

13

Put back the photomultiplier unit slowly.

14

Tighten the photomultiplier unit fixing knurled screws to fix the photomultiplier unit.

Check to ensure that it has been fixed tight.

15

Put back the cover and tighten the knurled screw.

16

Start up the system.