User guide

LBA-USB User Guide Document No: 11294 Page 53
Gauss Height, etc., will be computed in processed digitizer units. Processed
digitizer units are called counts, and are dimensionless. In this case, no units will
be displayed in the results window.
Any non-zero entry causes the displayed results to be reported in the units
selected. Fluence results also rely on the Pixel Units entry to complete the
energy density definition. A Pixel Unit selection of PX stands for pixel spatial
units. The PX unit is dimensionless.
When the Scale Units are set to µm, mm, or cm, the energy density results are
computed as energy/cm². When the scale units are set to PX or m, the density
results are displayed as energy/PX², or energy/m² respectively.
Energy Calibration Procedure
Once LBA-USB is set up ready to acquire data, the energy calibration procedure
involves the following three operations:
1. Execute an Ultracal! operation.
2. Acquire a calibration frame on the 2D display and a matching energy measurement
on an external power/energy meter.
3. Enter the energy and select the corresponding units in the Computations dialog
box.
Quantitative Display
Check the Quantitative box to have the quantitative results item appear in the
results window.
Checking this box only controls the display of these results. Even when not
checked, these results will be computed. The only way to turn off all
computational activity is to minimize the Results display window.