ThermoFisher Scientific Vanquish VC-D11, Руководство по эксплуатации, Страница: 102 / 192

6 • Operation
Page 102 Diode Array/Multiple-Wavelength Detectors (VC-D11, VC-D12, VF-D11)
Operating Manual
6.7.2.2 Selecting the Response Time and Peak Width
As a standard, when setting the data collection rate, Chromeleon
automatically sets the optimum response time and peak width. As an
advanced option, response time and peak width can be set individually.
TIP
Disabling the link between the data collection rate parameters and
setting these parameters individually may lead to increased noise or
increased peak widths.
Observe the following guidelines when changing the response time and
peak width proposed by Chromeleon:
• Ensure that response time and peak width match the setting for the
data collection rate.
• The response time should be about 30% 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. However, if the selected response
time is too long, this can result in reduced peak heights and
asymmetrical peak shapes. If a separation of peaks is done that
follow closely to each other, the long response time can result in bad
peak separation. When set correctly, the response time significantly
reduces baseline noise, and reduces peak height only slightly.
TIP For best possible combinations of data collection rate, response time
and peak width, enable the Link data collection parameters check box in
the detector settings of the Chromeleon Instrument Method Wizard or
Instrument Method Editor.
6.7.2.3 Optimizing the Bandwidth and Slit Width Settings
In the default factory setting, a bandwidth of 4 nm and a wide slit width
(VF detector only) are defined in Chromeleon. If required, both
parameters can be set individually.
The interaction between bandwidth and slit width has a substantial
impact on baseline noise, selectivity, spectral resolution of the peak as
well as linearity.