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neutron count rates on the display. The closer the
instrument is to the radiation source, the larger the
count rate value. In this scenario it is not necessary
to run background calibration while approaching
the source.
If the value of the dose rate exceeds the
instrument’s upper measuring limit for radiation,
the overload message on the LCD screen will
display “-OL-” for gamma radiation or “-999-” for
neutron radiation.
Alarms in the Search Mode
Alarm levels in the Search Mode are derived from
the ambient background. When the instrument runs
through background calibration, it acquires a
background reading and calculates the alarm levels
automatically based on the value of n coefficient
set by the user.
The value of n coefficient may be set in the range of
1.0 to 9.9 through every 0.1. The smaller is the value
of n coefficient, the more sensitive is the instrument
to changes in background radiation, however this
also increases the rate of false alarms (false
positives). The larger is the value of n coefficient, the
less sensitive unit becomes to minor changes in
radiation background and responds only to large
radiation field variations (intensive radiation sources
nearby) and probability of false alarms decreases.
Suppress NORM algorithm
It was implemented a special algorithm, that allows
excluding alarm signal when the natural gamma
background value increases and Naturally
Occurring Radioactive Materials (NORM) are
detected. When the gamma radiation DER grows, an
analysis is performed - is given the yellow indication
light. If NORM are detected - is given the green
indication light. In the case the other radionuclides
types are detected (IND, NUC, MED), the red
indication light and sound alarm will be provided.
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