BNC SAM 935 Portable Gamma Spectroscopy System - Manual (Page 47)

SAM 935™ Instruction Manual 43
F2, Edit an Isotope: Scroll down the list of isotopes to the isotope you wish to monitor. Press
E
NTER , and you will be returned to the Select list.
F3, Delete a Trigger: The trigger will be deleted.
F4, Change a Trigger Level: Use the
←
and
→
arrows to select a digit; use the
↑
and
↓
arrows to
change the digit. When you’re finished, press E NTER .
Monitor and Detail Modes Only: The strength of a trigger is measured in terms of standard deviations
above background, where the background is measured over the same region of the spectrum. For exam-
ple, in the case of a full spectrum, if the number of counts per second in the background spectrum was
100, then its standard deviation would be 10. If the number of counts in a measurement period was 145
counts per second, then the net counts above background would be 145 – 100 = 45, and the reported ratio
would be 45/10 = 4.5. This would trigger an alarm if the corresponding trigger level was set to 4 or less.
6.1.3 Set the Default Trigger Levels
The factory-set default trigger levels are:
5 All Isotopes
8 FULL Spectrum
7 Unidentified Peak
Default values apply only when an item is added to the list of triggers being monitored.
To change the default trigger levels:
1. Select Set Default Trigger on the Monitor Setup menu
for the type of default being set (Iso, Full, or Peak) and
press E
NTER :
2. Use the
←
and
→
arrow keys to select a digit; use the
↑
and
↓
arrow keys to increase or decrease the value.
3. Press E NTER when finished. C ANCEL will exit without
changing the original value.
4. Either select another default trigger level to edit or
press E
NTER to return to the Monitor Setup menu.
Cursor Points To F2 F3 F4
I SOTOPE – Allows you to
select an isotope
Any Isotope E DIT - Allows one isotope to
be replaced by another
D ELETE the FULL trigger
from the list
T RIG L VL – Allows you to
change the trigger level
FULL D ELETE – Removes the
FULL trigger from the list
T RIG L VL – Allows you to
change the trigger level
PEAK D ELETE – Removes the
PEAK trigger from the list
T RIG L VL – Allows you to
change the trigger level