Calibrating the wavelength of the nir spectrometer, About wavelength calibration, Calibrating the spectrometer – Ocean Optics NIR User Manual
Page 21: Preparing for calibration, Calibrating the wavelength of, The nir spectrometer, Appendix a
Appendix A
Calibrating the Wavelength of
the NIR Spectrometer
This Appendix describes how to calibrate the wavelength of your spectrometer. Though each
spectrometer is calibrated before it leaves Ocean Optics, the wavelength for all spectrometers will drift
slightly as a function of time and environmental conditions.
About Wavelength Calibration
You are going to be solving the following equation, which shows that the relationship between pixel
number and wavelength is a third-order polynomial:
λ
p
= I + C
1
p + C
2
p
2
+ C
3
p
3
Where:
λ
= the wavelength of pixel p
I = the wavelength of pixel 0
C
1
= the first coefficient (nm/pixel)
C
2
= the second coefficient (nm/pixel
2
)
C
3
= the third coefficient (nm/pixel
3
)
You will be calculating the value for I and the three Cs.
Calibrating the Spectrometer
Preparing for Calibration
To recalibrate the wavelength of your spectrometer, you will need the following:
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