5
ChromQuest Diagnostics for the PDA Detector
Controlling the Lamps with ChromQuest
78
Surveyor PDA Plus Detector Hardware Manual
Thermo Scientific
Controlling the Lamps with ChromQuest
As lamps age, they emit less light, which results in increased baseline noise. If the noise level of
your detector 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 as described in
does not help, replace the lamps. See
The detector keeps track of the number of hours each lamp has been operating. The
deuterium lamp has a lifetime of approximately 1000 hours and the tungsten lamp has a
lifetime of approximately 2500 hours. Lamp lifetime varies depending upon the application.
In the ChromQuest data system, the lamp controls are on the Lamps page of the PDA
Diagnostics.
To open the Lamps page in ChromQuest
1. Open the online Instrument window in ChromQuest.
2. In the menu bar of the Instrument window, choose
Control > Instrument Status
to open
the Instrument status window.
3. In the Instrument Status window, click the
Surveyor PDA Plus
tab to open the Surveyor
PDA Plus Instrument Status page.
4. Click
Diagnostics
to open the PDA Plus Diagnostics dialog box.
5. Click the
Lamps
tab to open the Lamps page, and then note the status and usage of each
lamp (see
Note
Avoid indiscriminately pressing either Reset button. They should be pressed
only after their associated lamp has been replaced with a new one.
Note
The intensity of the deuterium lamp falls off very slightly over a period of time
after it is turned on. You should wait at least 1 h for the lamp to stabilize after a cold
start before collecting data in the spectral range of the deuterium lamp.