Beckman Coulter Navios, Instructions For Use Manual

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773232AH
3-7
Operation Principles
Signal Processing
3
•
Part II of Figure 3.7 shows when the cell is in the center of the laser beam and the scattered light,
and therefore, the pulse height, reaches a maximum.
•
Part III of Figure 3.7 shows when the cell leaves the laser beam and the scattered light decreases.
The intensity of light scatter or fluorescence determines the height of the peak pulse (see
Figure 3.7 ). The time the particle is in the laser beam determines the width of the pulse. Therefore,
the total fluorescence (intensity and time) determines the area under the pulse. Figure 3.8 shows
how three cells with the same amount of total fluorescence but with different fluorescence
intensities, produce different peak pulses.
Figure 3.7
Voltage Pulse Formation, Peak Signal
1.
Laser beam
2.
Cell/Particle
3.
Volts
4.
Time
5.
Pulse height
b
c
d
e
b
d
e
c
b
c
d
e
f
I
II
III