BUCHI NIRCal - Manual (Page 26)

NIRCal 5.5 Software Manual
26 NIRCal 5.5 Manual, Version A
Select spectra for the calibration (Calibration Spectra = C-Set) and for the validation of the calibration
(Validation Spectra = V-Set). The C-Set will be used for the calculation of the calibration, the V-Set is
used as an internal test of the calibration.
The same spectra should not be defined as C-Set and V-Set Spectra at the same time. If so then the
spectra will be marked with a question symbol in the spectra overview and following message
appears, that easily allows to remove the spectra set overlap automatically:
Link:
Chemometrics / Selections / Spectra Data Set
Wavelengths selection:

All Wavelengths: the measured wavelength/ wavenumber range and the number of
wavelength / wavenumber data points, which is determined by the used instrument and by the
resolution;

Calibration Wavelengths: only the selected range will be taken into account for the calculation
and later for the application.
Link: Chemometrics / Selections / Wavelength Data Set
Properties selection:

All Properties: number of properties belonging to the imported spectra;

Calibration Properties: only the selected properties will be taken into account for the
calculation and later for the application. Normally all or several will be selected for Cluster
calibration, only one should be selected for quantitative and for SIMCA calibration method.
Link: Chemometrics / Selections / Properties Data Set
Principal Components Selection:

All PCs: the number of primary principal components used for the calibration, they are used
for the spectra reconstruction and for the Residual calculation;

Calibration PCs: only the selected PCs will be taken into account for the calculation and later
for the application, they are used in quantitative calibration for the property value calculation
or in qualitative calibration for the property separation and for the allowed tolerance area
calculation.
Link: Chemometrics / Primary Principal Components & Secondary Principal Components
Pretreatments selection:
The measured spectra can be modified before the calculation with several pretreatments or different
combinations of them.
NOTE
The original spectra are still the same and will not be modified.
The list of in NIRCal 5 implemented
pretreatments indicates the huge flexibility of the software. The
pretreatments used in the calibration will be applied in the application also.