Thermo Scientific RadEye GX Operating Instructions Manual page 41

Thus the actual alarm threshold adjusts itself automatically to the
existing background radiation level. The actual setting of the
alarm threshold 1 can be observed at the bar graph threshold
mark. At power on of the instrument, the background ratemeter
starts with its preset maximum background value, reaching its
final value after about 2 minutes.
Using the menu option , the exact value of
Alarm Count Rate
the alarm threshold currently valid at the respective background
can be displayed.
On acknowledgment of an alarm, the background ratemeter is set
to the actual count rate display. Accordingly the alarm threshold
is increased.
This is useful, if an alarm occurs while entering a zone with high-
er background level (certain buildings, subway...).
There will be no further alarms at background conditions and
normal sensitivity will be established again automatically after
about two minutes.
Alarm 2 is always referring to the total count rate without consid-
eration of any learned background.
RadEye GX, GX-L DB-074 E 3-19
Pi/Ff 14.09.2016