ThermoFisher Scientific Vanquish VC-D50, Руководство по эксплуатации

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6 • Operation
Page 114 Fluorescence Detectors (VC-D50, VC-D51, VF-D50, VF-D51)
Operating Manual
TIP In Multi-Channel mode, the response time and data collection rate
are always determined automatically. You can influence these
parameters by selecting a different multi-channel performance.
Data Collection Rate
The data collection rate is the number of data points per second (Hz)
that the Chromeleon software collects from the detector and stores as
raw data.
When you select a data collection rate, observe the following guidelines:
• In general, each peak should be defined by at least 20 data points.
For chromatograms with co-eluting peaks or low signal-to-noise
ratios, 40 data points per peak are recommended.
• If the data collection rate is too low, the start points, maxima, and
end points of peaks will not be determined accurately.
• If the data collection rate is too high, data files may need more disk
space and post-run analyses may require more processing time.
• If all peaks are relatively wide, select a lower data collection rate (for
example, 1.0 Hz). This saves disk space and allows for a faster display
of data in the Chromeleon software.
• If any peaks of interest are less than a few seconds, select a higher
data collection rate (10.0 Hz, for example).
• The selected lamp mode also has an effect on the maximum data
collection rate.
Response Time
The response time is a measure of how quickly the detector responds to
a change in signal.
• Select a response that is about 1/3 of the peak width at half-height
of the narrowest peak of interest. A longer response time allows
more averaging of the signal and results in less short-term noise, and
thus improves the signal-to-noise ratio.
• However, if the selected response time is too long, this can result in
reduced peak heights and asymmetrical peak shapes. Peaks that
elute shortly after each other may not be separated properly. When
set correctly, the response time significantly reduces baseline noise,
but reduces peak height only slightly.