User's Manual

Ocean Optics with Xplorer GLX Measurements

Absorbance

The GLX uses this equation to evaluate each pixel on the detector and

produce the absorbance spectrum:

Where:

= Sample intensity at wavelength λ

= Dark intensity at wavelength λ

= Reference intensity at wavelength λ (acquired with a blank

cuvette in place)

Absorbance is not a valid quantity if either or is

less than zero. This condition may occur if the test solution or the refer-

ence solution is very dark.

Transmission

The GLX calculates the transmission of a solution using this equation:

Rel. Irradiance

Relative irradiance is a comparison of the fraction of energy a sample

emits and the energy the spectrometer collects from a lamp with a black-

body energy distribution (normalized to 1 at the energy maximum).

To measure the relative irradiance of a sample, you must save the refer-

ence scan using a lamp of known color temperature and enter the color

temperature under the Lamp tab of the configuration screen.

The GLX calculates relative irradiance with this equation:

Where:

= Relative energy of the reference (calculated from the color

temperature) at wavelength λ

= Sample intensity at wavelength λ

= Dark intensity at wavelength λ

= Reference intensity at wavelength λ

log

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–()R

–()

–

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100%×=

–

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