Correcting Data - Horiba Scientific FluoroMax-4 Operation Manual

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FluoroMax -4 & FluoroMax -4P with USB rev. D (30 Jul 2012)

Correcting data

Introduction
Collecting accurate information about the fluorescent or phosphorescent properties of a
sample depends upon several factors:
Equipment specifications
Sample characteristics
Timing considerations.
To ensure that the spectra collected indicate the actual properties of the sample and not
external conditions, data often must be corrected. To correct data means to remove in-
formation from the data not directly related to the properties of the sample. Gratings,
detectors, and other spectrometer components have response characteristics that vary as
a function of wavelength. These characteristics may be superimposed on spectra, there-
by yielding a potentially misleading trace. For accurate intensity comparisons, such as
those required for quantum-yield determinations, response characteristics must be elim-
inated. Supplied with the instrument are sets
of excitation and emission correction fac-
tors to eliminate response characteristics.
1
, xcorrect and mcorrect,
These files
are included with the software.
Items that may be convo-
luted into a spectrum
Fluctuations caused by
the light source
Influence of the sample
holder
System hardware (e.g.,
optics, detectors)
To use radiometric correction factors, either:
Select the ones supplied with the program, or
Select a set generated at your facility during or after acquisition, discussed in the
following section. Acquiring radiometric correction factors is explained in Chapter
8: Producing Correction Factors.
Blank Subtraction and Dark Offset functions are described in the on-line
FluorEssence™ help files.
1
Filenames include a three-letter extension. For the sake of clarity, we have omitted the extensions in
this section.
Ways to remove these artifacts
Monitoring lamp output using the reference detector, R,
and using the signal ratio S/R to correct lamp profile or
temporal fluctuations
Running a blank scan (which is then subtracted from the
sample scan)
Using radiometric correction factors
5-14
Optimizing Data
Note:
The excitation range is
240–600 nm; the emission
range is 290–850 nm.