Ocean Optics Curie UV-VIS Emission - Manual (Page 53)

Appendix C
Relative Irradiance Mode
Irradiance is the amount of energy at each wavelength emitted from a radiant sample. In relative terms, it
is a comparison of the fraction of energy the sample emits and the energy the sampling system collects
from a lamp with a blackbody energy distribution (normalized to 1 at the energy maximum). OOIBase32
calculates relative irradiance with the following equation:
S λ - D λ
I λ = B λ
(
R λ - D λ
)
Where:
B λ
= Relative energy of the reference (calculated from the color temperature) at wavelength λ
S λ
= Sample intensity at wavelength λ
D λ
= Dark intensity at wavelength λ
R λ
= Reference intensity at wavelength λ
The figure below shows a typical relative irradiance setup: Use a light source with a known color
temperature such as the LS-1-LL to take a reference spectrum. The light source is coupled to the cuvette
adapter (such as the PS-HG1-ADP) with a fiber. The cuvette adapter is used to reflect light energy into
the spectrometer. The spectrometer then transmits the information to the PC, which compares the
measured spectra against the reference spectrum, thus removing wavelength-dependent instrument
response from the measurement.
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