Location:
Detection tab page
Report Variable (Detection Parameters)
Type:
Alternatives
Dimension:
---
Value Range:
Off; On; At current level /
At global minimum
Default:
Off
Related Parameters:
Description:
If the Lock Baseline parameter is set to Off, the detection program calculates the baseline below non-resolved peaks according to a complex pattern recognition process. The other values are used to lock the baseline on different levels.
Function:
Off
Under non-resolved peaks, the baseline is determined automatically. The Valley-to-Valley parameter is effective in this mode, only. With all other lock-values, lock baseline has priority, while valley-to-valley is ignored.
On
In case of non-resolved peaks, the baseline is not pulled up to the relative minima (valleys). The baseline connects the start of the first with the end of the last non-resolved peak.
If one of the valleys in between is located below the baseline, the baseline is connected with this minimum to avoid cutting off a peak foot. The Valley-to-Valley parameter is not effective.
At current level
The baseline is fixed at the current signal level and is extrapolated horizontally to the right. The Valley-to-Valley parameter will not take effect.
At global minimum
Chromeleon searches to the right for the next absolute minimum. The search is performed either to the end of the chromatogram or to the next Lock Baseline. Within this interval, the baseline is locked on the found minimum and is horizontal. The Valley-to-Valley parameter is not effective.
Tips:
The end of the last non-resolved peak in a series of peaks is always a baseline point, since the chromatogram itself forms the baseline outside the peak!
Lock baseline needs to be disabled, before switching from At global minimum to another lock baseline value.
The classification criterion Type (Peak Type) in the peak table has priority. The criterion specified here is effective only for Peak Type = AUTO!
