BSA Flow Software Installation and User's Guide - CSI

Methods to determine whether the LDA measuring volume is in position
Note For all the below procedures, it is important to protect the photomultiplier
tubes. Run the laser at low power and make sure that the PM current limit
property of the processor has been correctly set.If the PM current saturates,
reduce the PM high voltage.
The main difficulty is normally to determine whether the measurement
volume’s longest dimension is centered correctly. The below methods can be
used for this. The pinhole/power meter method is good for determination of
all three coordinates.
Pinhole/power meter method
A precise method is to mount a pinhole matched to the diameter of the
measuring volume within the flow rig, and accurately measure its position
relative to the laboratory origin. The LDA measuring volume must then be
moved to the position where maximum light power from all beams pass
through the pinhole. This method is highly repeatable, if a power meter is
used to measure the power of the beams after the pinhole.
Window surface/photomultiplier current method
Another often used method is to use a window surface as the reference for
the LDA measuring volume: if there is a window between the LDA optics
and the flow, and the LDA measuring volume can be traversed to the
window position, the detected Doppler signal from the wall or the PM anode
current will reach a maximum, when the center of the measuring volume is
at the surface of the window.
Model surface/photomultiplier current method
Similar to the window surface method, but if the surface is not transparent,
stronger reflections occur, and it may be necessary to reduce the PM high
voltage more. The automatic protection of the PM may further reduce the
high voltage. In this case, reduce the laser power if possible until the PM
current is below the allowed limit.
5.7.7 Saving traverse properties for use in other projects
To ensure that new projects use the traverse properties that you have defined,
it is necessary to perform the steps below.
The template function supports the properties of the Lightweight,
Lwhandbox and Generic traverse systems, but if you define new projects
without aplying a template, the traverse properties will be the system default
values.
To save traverse settings in such a way that they are automatically used in
future projects, you must right-click the traverse server icon and select
Save... This opens a dialog in which you can rename the traverse server to
any name that you wish, e.g. Lab Traverse.
In the Dantec Device Configuration, select Custom Driver, and type in the
name you gave the traverse:
5-42 BSA Flow Software: Project explorer objects