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Neutron detector in this mode continues to
work identical to the Search Mode.
To toggle between various operation modes, the
MODE button is used.
2.3.1. Search Mode
In the Search mode the
instrument displays the current
value of gamma and neutron
radiation count rate in s
-1
(counts per second) and
automatically compares the average count rate with
the threshold value (the value based on the
background radiation measured during calibration
and the n coefficient set by the user).
In this mode, the instrument is capable of searching
for and locating radioactive sources. When a
radioactive source is detected (the point at which
the calculated alarm threshold is exceeded), the
instrument will produce a visual and audio and/or
vibrating alarm. As the instrument moves closer to
the radiation source, the frequency of audio or
vibrating signals increase and thus enable the user
to determine the direction toward the source
location.
When the alarms signals reach their maximum
frequency it is recommended to run the
background calibration procedure (see section
Getting a new background
). During this process it is
important to keep the instrument in the same place
if possible. Once the background calibration is
completed, the user may then continue to search
for the radiation source. If necessary, this procedure
may be repeated as many times as necessary until
the gamma radiation source is located.
To operate the instrument or locate a neutron
radiation source in mixed gamma and neutron
radiation fields, it is recommended to switch OFF
the audio and vibrating alarms and manually
monitor the numerical values of gamma and
