Appendix D Optimizing the CANBERRA iSERIES for Air Sample Counting
Figure 17 Incorrect Results with Improper Gain Cal
It sometimes happens that a facility is aware that the gain calibration is set incorrectly
for their standards, yet they do not possess a proper Am-241 standard to perform a new
gain calibration. To verify that the gain is set correctly for a given sample matrix, use
the natural radon progeny found on a freshly collected sample to set the gain manually.
i
LINK software must be used if the system gain calibration is set manually.
In most locations, even a short sampling time will yield RaC' (Po-214, 7.68 MeV). The
peak from RaC' should be seen in channels 195-199. If the 7.68 MeV peak is out- side
of this range, the algorithm will not work correctly.
Figure 18 Gain Calibration Crosscheck
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iMatic Automatic Counting System User's Manual - 9239221K
