ThermoFisher Scientific Vanquish VC-D11, Operating Manual

Page: 96 / 192

6 • Operation
Page 96 Diode Array/Multiple-Wavelength Detectors (VC-D11, VC-D12, VF-D11)
Operating Manual
Parameters Description
Wavelength Sets a wavelength for each of the UV_VIS_x signal
channels individually, in the range of 190 nm to 800 nm.
The wavelength defines the value at which the detector
measures the absorbance of the analyte(s) in the sample.
Observe the following:
• Set the Wavelength to the wavelength with the
absorbance maxima for the analyte(s) of interest.
• For best selectivity, select a specific wavelength for
every substance to be analyzed with a low spectral
bandwidth, for example, by using a separate signal
channel for each analyte.
• To obtain optimum linearity, set the Wavelength to a
peak or a valley in the absorption spectrum. A valley can
provide best linearity for high concentrations.
Data collection rate Sets the data collection rate, at which data is to be
collected from the detector and stored as raw data. The
data collection rate applies for all signal channels and the
3D field (only available for the VF‑D11 and VC‑D11
detectors).
As a standard, when setting the Data Collection Rate
parameter in the Chromeleon Instrument Method
Wizard, the response time and peak width are defined
automatically.
For guidelines on selecting the data collection rate, see
Selecting the Data Collection Rate ( } page 101) .
Bandwidth The bandwidth specifies the spectral bandwidth (i.e. the
ability of the detector to distinguish between single
wavelengths), at which the signal channel (
UV_VIS ) is
recorded. In general, this corresponds to the spectral
resolution of a detector.
The standard Bandwidth is set to 4 nm. If required, you
can set a different value for the bandwidth.
For details on the bandwidth and setting a different value,
see
Optimizing the Bandwidth and Slit Width Settings
( } page 102) .
Slit width (only available
for the VF detector) The slit width determines how much light passes through
the adjustable entrance slit and is available for
measurement. As more light is available for the
measurement, the baseline noise is minimized. However,
the spectral resolution diminishes.
The setting of the slit width affects all signal channels and
the 3D field.
You can select between two different slit widths: Narrow
and wide. The recommended
Slit Width is wide. If
required, you can set it to narrow. Upon restarting the
detector, the last setting is used. For details on the slit
width and selecting it individually, see
Optimizing the
Bandwidth and Slit Width Settings ( } page 102) .