Doc. # 5016
BM-185D/285D/286D
Rev. A
Operation and Service Manual
3.4.2.7
Alarm Type
Selects method of generating a radiation alarm. The available options are:
1.
NSigma: ((N*
√
background) + background)
2.
nCi: nanoCuries above background
3.
SPACT: Specific Activity
3.4.2.8
Efficiency
The efficiency of the detectors, in percent, to the source activity. This value is used in calculating
the activity. This value may be either entered manually or automatically calculated by the
BM-185D/285D/286D. Press on the white box and enter a value, or press auto to allow the unit
to calculate the efficiency.
1.
Manual entry method: Enter efficiency in percent.
2.
Automatic calculation: The operator will be prompted for a count time (in
seconds) and the calibration source activity (in nanoCuries). Press BEGIN, at
which time a START button will appear. Press the START button and the unit
will then take an nn second background. The operator will be prompted to place
the source in the center of the chamber and press START to accumulate an nn
second count with the source in the chamber. The efficiency will be displayed in
the efficiency window.
3.4.2.9
Alarm Level
The operator will be prompted for the alarm level (depending on the alarm type selected above).
Enter the alarm level in the appropriate units. The previous value will be displayed, and will only
be accepted by entering it again or a new value may be entered.
1.
ACT
: Activity is displayed in either nCi or Bq.
2.
N*Sigma
: Radiation alarm level in N*Sigma (N*
√
bacbackground).
This is the count level that will generate a radiation alarm when N*Sigma alarm type is
selected.
This value is used only when the Alarm Type is set to N*Sigma.
3.
SpAct: Radiation alarm level, above background, in pCi per kilogram or nCi per
kilogram.
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