Ocean Optics RaySphere 1700 Install - Manual (Page 60)

9: Nonlinearity Correction, Stray Light Correction and Calibration
50 RAYSPHERE-1700-02-201304
The Deviation in [%] is defined as:
Deviation[%]= (1 - SP_Cal/SP_Raysphere) x 100
Variables are defined as follows:
SP_CAL = Spectrum from calibrated light source from Heraeus (calibrated by German PTB)
SP_RaySphere = measured spectrum from RaySphere
The peaks in the infrared at ~1400 nm and ~1700 nm results from water adsorption of humidity in the air.
The humidity in the air at the Ocean Optics calibration lab is different than the humidity at Heraeus
Noblelight during the calibration test.
Uncertainty in Absolute Irradiance and Uncertainty in Spectral Distribution
The spectral match test measures the spectral distribution of the solar simulator. The exact value of
absolute irradiance is not of importance in principle. Since standards are available only for absolute
irradiance and not for spectral distribution one has to quantify the uncertainty of spectral distribution from
the spectrum in absolute irradiance.
The deviation between RaySphere’s data and emission spectrum from the calibration lamp at Heraeus test
lab is the basis for extracting the uncertainty for spectral match test. The deviation can be described as an
offset and a change in spectral distribution. The offset can be subtracted without changing the spectral
distribution. An example with generated data is shown in the graph below.