BSA Flow Software Installation and User's Guide - CSI

Polarization ring
Fixing screw
Push rod
Fiber manipulator
Figure 7-54. The fibre plug has a push rod that activates the transmitters
automatic safety shutter to allow laser light to pass. The polarization ring,
which holds the push rod, has to be rotated to change the polarization state.
7.4.2 Configuring the PDA receiving optics
Front lenses and beam expanders
As a general rule, the shorter the focal length, the smaller the particles that
can be measured; the longer the focal length, the larger the particles that can
be measured. The focal length also corresponds to the working distance.
The particle size range measurable by the PDA can be changed in several
ways and thus, the PDA probe can be configured to suit the measurement
application:
• mounting a selection of front lenses and beam expanders
• using different aperture plates
Front lenses The PDA probes can be fitted with standard front lenses from the 60X
FiberFlow optics and, using the 60X117 Conical Adapter which is supplied
with every PDA probe, front lenses from the 50X optics series (see Table 7-
1).
To facilitate alignment of the PDA receiving probe, Table 7-1 also contains
the focal distances of the different lenses. The distance between the front
side of the lens (at the center point of the lens) and the focal point (which
should coincide with the measurement volume) is called the focal distance
and can easily be measured using a ruler.
Caution When using a ruler to check the focal distance, be careful not to scratch the
lens.
Type no. Focal length Focal distance Notes
mm
mm
60X70 160 155
50X57 310 300 Requires adapter 60X117
BSA Flow Software:Reference guide 7-73