6
Routine Maintenance
Replacing the Lamps
Thermo Scientific
Surveyor PDA Plus Detector Hardware Manual
91
7. See
“Installing the LightPipe Flow Cell”
for instructions on how to reinstall
your flow cell.
Replacing the Lamps
As lamps age, there is a reduction in light output, which results in increased baseline noise. If
the noise level on your detector output signal is unacceptable, and cleaning the flow cell does
not help, use the diagnostic features of the software to determine the cause of the problem. If
light output becomes too low and adjusting the attenuators does not help, replace the lamps.
The detector keeps track of the number of hours each lamp has been operating. The
deuterium lamp has a lifetime of approximately 1000 h and the tungsten lamp has a lifetime
of approximately 2500 h. Lamp lifetime varies depending upon the application.
If the light output becomes too low and adjusting the attenuators does not help, replace the
lamps. The lamps are pre-aligned on small mounting blocks to facilitate replacement.
The deuterium (D2) and tungsten (W) lamps are located in the lamp compartment to the
right of the optical bench assembly (viewed with the detector chassis open as shown in
).
You must have the following tools to replace the lamps:
• narrow-blade screwdriver (2 mm wide)
• #2 Phillips head screwdriver
• 1/4-in. open end wrench
To replace the deuterium and tungsten lamps
1. Turn the power switch at the front of the detector to Off (released position) and
disconnect the power cord from the back panel.
2. Open the front doors by swinging each door outwards.
3. Remove the flow cell as described in
“Removing the LightPipe Flow Cell”
.
CAUTION
Intense UV light can damage your eyes! Always turn off the detector and
disconnect the power cord before you expose the lamp.
CAUTION
Always allow sufficient time for the lamp to cool before removing it. The
lamp gets very hot when it is illuminated.
