User manual

1200 Series Variable Wavelength Detector User Manual 57
Using the Detector 4
Scanning with the VWD
1 Set up a run.
2 Start a run.
3 While running on the baseline, select from the menu
Instrument - More VWD - Blank Scan, see Figure 22 on page 57.
A background scan is stored in the memory.
4 When the peak of interest enters the flow cell, stop the flow (set flow rate to
zero or open the purge valve) and wait a few moments to stabilize the
concentration.
NOTE
Access to the scan feature is only possible during run.
Figure 22 Taking Online Spectra
• Step 1: Blank Scan: scan of the background
(solvent) is stored in the memory.
• Step 2: Sample Scan: scan of the peak of
interest is taken while the peak stays in the
flow cell (stop-flow condition).
• Online Spectrum: Sample Scan minus
Blank Scan.
NOTE
Turning off the pump would stop the run and no access to the sample scan is possible.