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Xcalibur Diagnostics for the PDA Detector
Adjusting the Light Throughput with the Xcalibur Data System
Thermo Scientific
Accela PDA Detector Hardware Manual
43
3. Load the display method to the detector, and click
Start Data
The spectrum of light intensities appears in the top window.
For the UV region, the diode of maximum intensity is between diode 10 and diode 40.
For the Visible region, the diode of maximum intensity is between diode 400 and
diode 500. Ignore the spike at approximately diode number 380. This spike is an
emission line of the deuterium lamp.
4. Adjust the left attenuator tab (UV attenuation) to achieve a Channel A value as close as
possible to 900000 intensity counts without saturating the array.
5. Adjust the right attenuator tab (Visible attenuation) to achieve a Channel C value as close
as possible to 900000 intensity counts without saturating the array.
6. After you finish adjusting the attenuators, close the front doors of the detector.
IMPORTANT
With a new deuterium lamp, when you select the 20 Hz option for the
diode array scan rate, you can typically adjust the intensity to an optimum value of
900000 to 950000 counts. If you adjust the intensity too high, you can saturate the
array. So take care to avoid saturating the array.
