FluoroMax-3 v. 3.1 (6 Mar 2006)
FluoroMax
®
-P Phosphorimeter Operation
9-2
Theory of operation
A second source of illumination, a pulsed xenon lamp, is used for phosphorescence
measurements. Samples are excited with pulsed light; the emitted phosphorescence is
measured using an R928P photon-counting detector.
Sequence of data acquisition
The illuminator housing, or flash lamp, operates at up to 25 Hz. The control module
triggers each lamp pulse. When the start of the light output is detected, a signal is sent
to the control module for timing purposes. The control module houses the signal-gating
circuitry that intercepts the signal from the pulse-counting emission photomultiplier
tube, collects a selected, time-delimited portion of the signal, and later passes it to the
software. The maximum signal detectable per flash varies with the integration time:
Integration time
Maximum signal (counts) per flash
100 µs
400
1 ms
4000
10 ms
40 000
100 ms
400 000
1 s
4 000 000
With, for example, 100 flashes of integrated over 10 ms each, the maximum detectable
signal is:
100 flashes × 40 000 counts = 4 000 000 counts total
A typical
sequence
of data-
acquisition
starts with
a flash
from the
pulsed
lamp,
sensed by the control module as time
t
= 0. The light enters the excitation monochroma-
tor, where it is dispersed. Monochromatic light from the monochromator excites the
sample. Luminescence emission from the sample then passes through the emission
monochromator to the photomultiplier-tube detector. The control module includes a
gate-and-delay generator, allowing the signal at the detector to be integrated only dur-
ing a specific period after the flash (the
Initial Delay
), for a pre-determined length of
time (the
Sample Window
). Any signal arriving before or after the gating is ignored.
This sequence of excitation, delay, and collection is repeated for each lamp pulse. The
total signal is accumulated for a pre-determined number of exciting pulses (flashes) and
saved to disk. The data then can be manipulated using the
Analysis
menu.
Summary of Contents for FluoroMax-3
Page 5: ...FluoroMax 3 v 3 1 3 Mar 2006 v 15 Declaration of Conformity 15 1 16 Index 16 1...
Page 6: ...FluoroMax 3 v 3 1 3 Mar 2006 vi...
Page 18: ...FluoroMax 3 v 3 1 3 Mar 2006 Introduction 0 12...
Page 36: ...FluoroMax 3 v 3 22 Feb 2005 System Description 2 8...
Page 96: ...FluoroMax 3 v 3 1 3 Mar 2006 Maintenance 6 12...
Page 156: ...FluoroMax 3 v 3 1 6 Mar 2006 Automated Polarizers 10 22...
Page 208: ...FluoroMax 3 v 3 1 6 Mar 2006 Bibliography 14 4...
Page 210: ...FluoroMax 3 v 3 1 6 Mar 2006 Declaration of Conformity 15 2...
