Ocean Optics Overture - Manual (Page 18)

Chapter 3: Overture Software Icons and Menus
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Color
Overture can fill the space under the spectrum with an artificial display of spectral color. The color
display covers the visible range of 380nm to 780nm. Outside that range is
UV and NIR (near infrared)
and of course we cannot see colors there.
Transmission
Note
Transmission and Absorbance modes are only enabled when dark and reference readings
have been stored.
Transmission is the amount of light transmitted through the sample as a percentage of the light
transmitted through the reference. When you select Transmission mode, the y-axis units change to
percentage.
Where:
S
λ
= Sample intensity at wavelength λ
D
λ
= Dark intensity at wavelength λ
R
λ
= Reference intensity at wavelength λ
So now you can see why you need dark D
λ
and reference R
λ
readings. If you don’t have them, the math
won’t work!