Exploranium GR-100, User Manual

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GR-100 User's Manual Revision 1.2 2.0 Operation
2.8 Alarms
For normal use the unit is operated in the MONITOR mode. In this mode, the signal is analyzed for
alarm conditions and the results are updated every second.
2.8.1 Alarm Level Setting
After start-up a 5 second average of the local radiation background is computed and stored in memory.
This is the
S art Background
. The system automatically updates this background every 10 seconds using
a special algorithm that creates an accurate representation of the local background. This is referred to as
the
Local Background
.
t
The Alarm Threshold is a parameter in the unit’s memory that you can set. The unit automatically sets
the Gamma Alarm Threshold by applying the Gamma Parameter that you set via the PC Monitor 105
program to the background. The Gamma Alarm threshold setting represents the number of standard
deviations (Sigma) of the local background radiation signal by which the measured signal must exceed
the background signal to trigger an alarm. The gamma threshold is constantly adapting to varying
background conditions.
The local background is constantly updated unless an alarm occurs, in which case the updating is
suspended until the alarm is cancelled and Monitoring mode is restarted. It is strongly recommended
that you step back from the source before switching to Monitor mode to make sure the background is
truly reflective of only the local radiation level and not the anomalous level due to the detected source.
Also note that once the alarm threshold is set using this technique, the unit is usable in any local
radiation setting without further need for readjustment. The alarm level is automatically changed to
adapt to local radiation conditions.
2.8.2 Alarm Level actions
The GR-100 unit is typically worn on a belt. You are alerted to an alarm by an audio beep and/or
vibration action, depending on the system settings selection. In alarm condition, you can glance down at
the unit and see the flashing LEDs through the transparent windows as a visual reinforcement that an
alarm has occurred.
The following indications are present when an alarm occurs:
• The AUDIO transducer beeps in a warning mode of 5 triple-beeps that are approximately 2 secs
apart.
• The appropriate LED lights up (YELLOW=Gamma, RED=Neutron) in a
flashing mode ones per second.
GAMMA ALARM
PRESS BUTTON
44.4 µR/h
• The VIBRATOR is activated 5 times, provided it is enabled.
• The LCD screen shows:
SAIC/Exploranium – Proprietary Page 8 Revision Date:
November 2004