Metrohm NIRS XDS Transmission OptiProbe Analyzer - Manual (Page 44)

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The black spectrum is SRM-2035. The gray spectrum is XC-1300, which is used to calibrate the
wavelength scale of the XDS Rapid Liquid Analyzer.
Note that the XC-1300 standard used to calibrate
the XDS Rapid Liquid Analyzer shares many of the
same peak absorptions as SRM-2035. Both
materials use some of the same rare earths, and the
absorbances would naturally fall in the same places
in the NIR spectrum.
The XC-1300 standard has additional peak
absorbances, especially at the higher wavelengths.
These additional wavelengths permit accurate
calibration of the wavelength scale beyond that
offered by SRM-2035.
A note about the XC-1300 Transmission Calibration Standard:
When first offered, the XDS Rapid Liquid Analyzer used a wavelength standard labeled WST3WCAL.
It was later determined that better transferability between instruments could be achieved if each
standard was calibrated on the Metrohm NIRSystems master transmission instrument. Since that
time, each WST3Wxxx standard is serialized, with a matching calibration file. For example, the
standard may now be labeled “WST3W068”. The calibration file is contained on a mini-CD that
contains the file “TSS3W068” for that specific standard. Each serialized standard has a unique
number.
The wavelength scale response of the instrument is established by instrument optical design. This is
fine-tuned at the time of manufacture and testing. An initial wavelength assignment is made during
Wavelength Linearization. In Instrument Calibration, the XC-1300 is used at the sample plane to
make a final adjustment/verification of the wavelength response. By performing this function at the
sample plane (where user samples will be scanned) the analytical response of the instrument can be
assured.