5 Maintenance and Inspections
5.5 Replacing Photomultiplier
68 FPD-2010
6.
Remove the photomultiplier from the socket. Be careful not to contaminate and/or damage the light
receiving portion, using soft gloves and the like.
Fig. 5.5.6
7.
After inserting a new photomultiplier into the socket, mount it by following the removal procedure in
reversed order. If difference of height exists at the connecting portion of the lens and the
photomultiplier, stray light may result. When mounting the photomultiplier, adjust the height using
screws at two locations on the shielding plate at the lower portion of that photomultiplier so that no
inclination will be made. (In most cases, it is not necessary to change the height as the unit is so
adjusted at installation that any inclination is eliminated.)
Make adjustment using
these two screws.
Shield plate
Fig. 5.5.7
NOTE When Photomultiplier is replaced, due to varying characteristic of each photomultiplier, peak area for the
identical sample may be different from that of the previous photomultiplier. If you wish to coincide it with the
previous peak area used before replacement, change the value of the detector signal gain to:
Peak area before replacement/Peak area after replacement × (Currently set gain value).
To change the gain, press the [FUNC] key and select “6. GC Configuration” in the selected screen. Further,
select
“5. Signal Setting” and press [PF2] (Gain etc.) to display setting screen for gain.
For the details, refer to “16.6.7.6 Offset of signal” in the main unit instruction manual.
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