Vision has an option to import DA files (from NSAS ) into a project, so we import the file which comes with our standard set and we will see one file called R80xxxxx (the “x” are the serial number of the standards box set). This file is our Master Reference file.
If we acquire the spectra of this R80xxxxx in the Host instrument (our instrument), without reference standardization , the spectra is quite different to the Master spectra, so a Reference standardization is needed in order that the Master and the Host have in common the same reference spectra when acquiring a sample.
In the next picture we see the spectra of the R80xxxxx (Red in the Master and Blue in the Host without Ref STD).
We run the Reference standardization and a STD file is created to correct this differences from the Host to the Master. Other Hosts do the same and the idea of more transferable equations (between instruments) is possible because we are correcting most of the instruments differences.
Here we are not correcting wavelength shift, just photometric response.
There are standards sets with different ceramics in order to check the photometric response of the Host to the Master at different reflectance levels (R99xxxxx, R40xxxxx, R20xxxxx, R10xxxxx and R02xxxxx).
Let´s compare the R99xxxxx passed in the Host instrument with and without Reference Std.
Without Ref Std:
With Ref Std: