BNC SAM 935 Portable Gamma Spectroscopy System - Manual (Page 27)

SAM 935™ Instruction Manual 23
If the SAM 935 detects that the background reading is unusable or non-existent, it will present this
screen, which
requires you to take a background reading:
4. To take the background reading, first remove the Cs137 standard from the vicinity of the detector.
Then press B
KG (F2) to begin acquiring the background spectrum.
5. The automatic background adjustment will take 1
minute (the factory setting); the spectrum will be dis-
played on screen as it resolves:
6. When the calibration adjustments are done, the dose rate monitoring screen will appear and you
can begin taking samples:
4.3 Powering the SAM 935 Off
Whenever the SAM 935 is turned off, all information is saved in battery-backed-up RAM. This allows you to
start up again without loss of calibrations and other information. Note that if the internal lithium battery has
failed, the self-test display will indicate the problem.
1. Power off the SAM 935 using the On/Off push button on the front panel, located behind the sliding
door.
Remove the Cs137 standard and press F2 to
immediately begin the background reading.
If the SAM 935 is unable to coarse adjust, it will tell you. (You may notice that the peak is too
far to the right of the screen or off the screen because the high voltage and gain are too high.)
If you see this message, it usually means the energy range was too high before the quick cal-
ibration was started. Press C
ANCEL and go to the Utilities menu to calibrate. When prompted
to reset hardware values, answer Y ES . Perform a coarse calibration and background reading;
the fine calibration does not need to be redefined if the last one was valid.