PDA-100 Photodiode Array Detector
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Doc. 031644-02 9/03
Bunch Width
The bunch width setting determines how many nanometers are averaged when
collecting 3D data. The default is 1 nm. Selecting a bunch width above 1 nm will
reduce the required data storage by the reciprocal. For example, a bunch width of
5 nm requires one-fifth the amount of storage as a bunch width of 1 nm. This
parameter reduces the spectral resolution, so do not select a bunch width when the
spectrum of the compound has a fine structure.
Step
A
step
is the time interval between two successively stored data points. The
smaller the step, the more data points that are recorded and, in general, the more
precise the analytical results. However, because collecting more data points
requires more storage capacity, the step setting sometimes represents a
compromise between the amount of information collected and the file size.
The user does not need to select a step setting; PeakNet 6 or Chromeleon
automatically selects the step value that is the inverse of the data collection rate.
For example, if you set the data collection rate to 5.0 Hz, the software sets the step
to 0.2 second.
The following table indicates the automatically selected step setting for each data
collection rate.
The appropriate PDA-100 step setting is automatically selected by the
software.
Data Collection Rate
(Hz)
Step
(seconds)
0.25
4.0
0.5
2.0
1.0
1.0
2.0
0.5
2.5
0.4
5.0
0.2
10.0
0.1
