horiba FluoroMax-3, Operation Manual

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FluoroMax-3 v. 3.1 (6 Mar 2006) Automated Polarizers
10-7
6
Apply the proper voltage on S (950 V for an
R928P photomultiplier).
7
Open the excitation shutter (if applicable).
8
Click the Accessories icon.
9
Set both polarizers to VV (0°).
10
Check the signal on S. Set slits evenly for each
monochromator to result in 1–1.5 million cps on
S.
11
Record the four permutations of the polarizers:
VV, HV, VH, and HH.
12
Subtract the dark counts from each permutation.
For example, VV
′ = VV – dark counts.
13
Calculate the polarization ratio using the dark-
subtracted data (e.g., VV
′ ).
14
If the polarization ratio ≥ 100, then the polarizers
are satisfactorily aligned. If not, then polarizers
should be re-aligned.
As an alternative, use an Anisotropy scan to acquire the polarization ( P ) or anisotropy
(< r >) to verify alignment. To be aligned, P ≥ 0.98 or < r > ≥ 0.97.