Metrohm NIRS XDS MasterLab Analyzer - Manual (Page 95)

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Note that the peak position is shown only to two digits after the decimal point. Any further digits are
not considered significant, and are therefore not displayed.
Wavelength Certification also tests certain “measured instrument profile” peaks in the wavelength
standard. These peaks are used to set the “Instrument Wavelength Profile,” and one peak is used for
bandwidth calculation.
The wavelengths used for the instrument wavelength profile are well-defined, stable peaks in the
wavelength standard. These are the same peaks used during Instrument Calibration. Wavelength
Certification is verification that the peaks are located in the correct positions, and that the peak
positions are consistent over time. Note that both tests use the wavelength standard at the sample
plane, where actual sample measurement is done.
Wavelength Certification is an excellent method to test whether Instrument Calibration needs to be
re-run. If the original settings in Instrument Calibration have drifted, a message will be displayed in
Wavelength Certification that Instrument Calibration should be re-run. Click on the Instrument
Calibration tab to see the results:
The wavelength peaks used here are not the NIST peak positions, though they are within +/- 1.0nm
of the NIST peaks. The peaks used in Instrument Calibration are the peak positions used to assure
transferability of the XDS instrument, and are defined based upon tests of many XDS instruments.
The acceptance specification in this test is tighter than in Wavelength Certification.
Note that Performance Test measures peak positions of internal reference materials, and these
positions are used as a preliminary method to maintain wavelength measurement. The final
measurement is made at the sample plane, using the external standard. As discussed under
Performance Test, the internal reference materials are not traceable, and are only used as an internal
method of maintaining correct wavelength measurement prior to measurement of the external
wavelength standard.
If the test has passed, the user may click on “Print Report” or “Close Report”. The test is saved in the
Diagnostic Database for future recall. See the Vision manual for a full explanation.