Horiba Scientific FluoroMax-4 Operation Manual page 34

® ®
FluoroMax -4 & FluoroMax -4P with USB rev. D (30 Jul 2012)
When setting slit width, the trade-off is intensity of signal versus spectral resolution.
The wider the slits are, the more light falls on the sample and detector, but the resolu-
tion decreases. The narrower the slits are, the higher the resolution gets, but at the ex-
pense of signal. Set the slits for intensity toward the higher end of the detector's linear
response, with sharp-enough resolution to discern desired spectral features.
Slits may be set in bandpass units, or the physical width of the slit (mm). Under
bandpass units, each monochromator's slits are set simultaneously, for the bandpass is
determined by the dispersion of the monochromator:
bandpass (in nm) = slit width (in mm) × dispersion (in nm mm
The dispersion of FluoroMax
1200 grooves mm
corresponding bandpasses.
Slit width (mm) Bandpass (nm) Rounded bandpass (nm)
0.50
1.175
2.00
Shutters
An excitation shutter, standard on the FluoroMax
monochromator's exit slit. The shutter protects samples from photobleaching or
photodegradation from prolonged exposure to the light source. FluorEssence™ controls
the shutter, and can set the shutter to automatic or photobleach modes. An emission
shutter is an optional accessory, placed just before the emission monochromator's en-
trance, and protects the detector from bright light.
Sample compartment (3)
A toroidal mirror focuses the beam from the excitation monochromator on the sample.
About 8% of this excitation light is split off, using a beam-splitter, to the reference pho-
todiode. Fluorescence from the sample is then collected and directed to the emission
monochromator.
The sample compartment accommodates various optional accessories, as well as fiber-
optic bundles to take the excitation beam to a remote sample (or the MicroMax), and
return the emission beam to the emission monochromator. See Chapter 12 for a list of
accessories.
®
-4 monochromators is 4.25 nm mm
–1
at 540 nm. Below is a table showing standard slit-widths with their
2.125 2
4.994 5
8.500 8.5
Caution:
Operation of the instrument when the excitation
shutter is disabled may expose the user to excessive
light. Wear light-blocking goggles or face-shield, and
light-blocking clothing and gloves.
–1
–1
®
-4, is located just after the excitation
2-4
System Description
)
for gratings with