NOTE: It is not necessary to fix a symmetrical percent around the peak. In fact, some isotopes
are multi-peaked, which can cause an asymmetric spectrum. Keep in mind that if a calibration
is performed you must save the result in order to have it used in ROI calculations.
If you select an isotope from the Isotope Editing page, the screen will display the isotope name,
LLD, ULD and range setting as demonstrated in the following chart.
RANGE
Min keV Max keV Half Scale
0 3000 1500
0 1500 750
0 1000 500
0 750 375
0 500 250
0 375 187
0 250 125
0 188 94
0 125 62.5
0 95 47.5
0 64 32
0 45 22.5
A. Lower Level Discriminator (LLD) = 0.85 times the Min keV of interest.
B. Upper Level Discriminator (ULD) = 1.15 times the Max keV of interest.
NOTE: Some isotope ROIs are preset so they are not ±15%. Using an isotope sample the ROIs
were determined for those isotopes.
To Next Page
Loading...
