NIR calibrations are used for NIR contents analysis as a productive analytical method.
That is a two step procedure.
A NIR analyzer does a non-destructive optical scan of a sample that yields a measured spectrum in seconds.
A NIR calibration model can quantitatively predict (analyze, determine, estimate) multipleconstituents, ingredients, contents, analytes, assay, API and other parameters and attributes (chemical, physical, biological, biochemical, sensory) summarized as properties, out of a single spectrum in milli seconds.
The NIR analysis is a very fast non-destructive analysis method that can replace or backup slower methods like wet chemical analysis, chemistry laboratory, sensory panels or rheology (viscosity).
Or a NIR calibration can open the door to new possibilities of analytics, quality assurance and process control, by developing calibration models for parameters that seems to be impossible, because they are based on human knowledge, empirical values or sensory like taste value.
If you have an NIR instrument, you can measure your samples systematically and thus develop your own calibration models.