Alignment - Horiba Scientific FluoroMax-4 Operation Manual

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

Alignment

Introduction
Polarizer alignment is verified by measuring the anisotropy of a dilute scattering solu-
tion. Scattered light is highly polarized, and this allows a simple check of the crystal
alignment in the instrument. We recommend using a very dilute solution of glycogen or
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Ludox (colloidal silica) as the scattering sample. The Ludox
is Aldrich 420859-1L, Ludox
de-ionized.
The alignment test may be a measurement of the polarization or anisotropy within the
software using the Anisotropy scan-type, or use of the Remeasure Anisotropy Only
utility (click Advanced..., and the Polarizer Alignment window opens). The test also
may be performed manually using the Real Time Control application. One measures the
polarization, anisotropy, or the polarization ratio of scattered light (typically, the excita-
tion and emission monochromators are both set to 370 nm for the measurement). To
calculate the polarization ratio, use the definition:
polarizati
Alignment is satisfactory when the polarization ratio ≥ 100, or P ≥ 0.98, or r ≥ 0.97.
Note:
scatterer. Use only a slight amount of scatterer to align the system.
The check below assumes a sample of Ludox
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TMA Colloidal Silica, 34 wt. % suspension in water,
Caution:
Refer to your Material Safety Data Sheets
(MSDS) for hazards regarding the use of glycogen,
colloidal silica, or other scatterers.
I I
VV HH
on ratio
I I
VH HV
The polarization ratio can be lowered by using concentrated
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we use as the reference
(9)
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or glycogen is used.
10-6
Automated Polarizers