User guide

Page 58 Document No: 11294 LBA-USB User Guide
Histogram
Check this box to generate a histogram of your laser beam’s energy distribution.
The histogram graphic and numerical results will appear in its own window of
LBA-USB’s main display. The size of each bucket in the histogram is user
programmable. Bucket size is based on the integer values produced by the A to
D converter. If required, the bucket size will be converted to floating point values
to reflect the processing effects of an energy calibration. The buckets are sized
up (plus) and down (minus) from zero.
Enter the Bucket Size in the provided field. A good value to start with is 16, 64,
or 256, depending on the number of bits per pixel the camera in use provides (8,
10, or 12-bit format).
Refer to section 4.22 for additional details.
Statistics
Check this box to add of statistical information to the Results window.
Statistical results will be computed for every numerical results item that appears
in the Results window. The statistical results provided are: Mean, Standard
Deviation, Maximum, and Minimum. To view these results, either maximize
the Results window or use the horizontal scroll bar to bring the values into view.
There are three ways to control how many samples are used to generate the
statistical results calculations:
 Continuous – Statistical results begin to accumulate when Start! is clicked and
continues until Stop! is clicked.
 Frames – Enter the number of frames of data to accumulate for statistical
purposes. Click Start! to begin statistical data collection. The collection will stop
automatically when the designated number of frames accumulates.
 Time – Enter the desired collection duration in Hours:Minutes:Seconds. Click
Start! to begin statistical data collection. The collection will stop automatically
when the time frame expires.
While performing any of the above, click Stop! and Start! to pause and resume
statistical data collection. However, for Frames and Time controls, a restart
does not resume the cycle from the point of interruption. Rather, the cycle resets
to the duration values set in the dialog box, but does not clear the prior
accumulated stats.
To continue adding more data to the results set, click on Start! after the frame
count or timer has run out. The cycle will complete a second time.