Metrohm NIRS XDS SmartProbe Analyzer - Manual (Page 47)

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When method transfer (between instruments) is anticipated, be sure that Reference
Standardization and Instrument Calibration are selected. These features assure best method
transfer between similar instruments.
Some of these selections are spectroscopic
calibrations, and are used to apply corrections to
the instrument to minimize differences between
units of the same configuration.
The correction programs are accessed from the
Diagnostics menu bar, shown at right. The
diagnostic steps are explained in the sections that
follow.
7.1.1 Wavelength Linearization
Wavelength Linearization uses an internal wavelength standard set to determine a set of internal,
arbitrary peak positions that the instrument will use to maintain repeatability of wavelength response.
The NIR wavelength positions of
these peaks appear as shown.
The scale of this display is marked
in encoder pulses, which do not
relate to nanometers directly.
From the peaks, a linearization is
performed, which allows
assignment of nanometer values.
The “visible” portion of the
spectrum is similar. A linearization
is applied to this portion of the
spectrum.
Minor artifacts appear in these
raw spectra due to detector
crossover and other spectroscopic
reasons. After linearization these
artifacts are minimal or not
evident, some being beyond the
usable range of the instrument.
These peak positions are not meant to be traceable, as the wavelength calibration of the instrument