Ocean Optics RaySphere 1700 Install - Manual (Page 55)

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Chapter 9
Nonlinearity Correction and
Calibration
Overview
The signal from the spectrometer has to be processed for several corrections to get the highest possible
precision. The most important processes are described in the following paragraphs.
Nonlinearity Correction
The spectrometer’s signal is automatically corrected for nonlinearity by an internal algorithm. The
function cannot be disabled in the RaySphere software.
Wavelength Calibration
The wavelength (measured in nanometers) of the spectrometer(s) in your RaySphere unit has been
calibrated before leaving Ocean Optics. See the appropriate spectrometer manual (NIRQuest and/or
QE65000) for more information on spectrometer wavelength calibration in
Product-Related
Documentation .
Absolute Irradiance Calibration
Absolute irradiance calibration of the RaySphere system is done in the calibration laboratory of Ocean
Optics GmbH Germany. For recalibration, it is recommended that any recalibration, if necessary, be done
there as well.
The equipment used for calibration is listed on the Ocean Optics calibration certificate. Ocean Optics
calibration light sources are traceable to NIST standards and all other equipment used is ID-traceable to
NIST or German PTB standards.
The spectral data use physical units of µW/cm^2/nm and the wavelength is in nanometers.
Uncertainties Calculation
The calculation of uncertainty is done in accordance with the IEC Guide 115 Application of uncertainty of
measurement to conformity assessment activities in the electrotechnical sector.