13
normal operation Mode and alarms
after PM1904 is charged and disconnected from the power source
it is ready for autonomous operation. The green light flashes every
10 seconds and the instrument continuously measures DeR and
De of gamma radiation and compares it to the preset thresholds.
If the thresholds are exceeded, PM1904 alerts the User with a red
leD indicator. If the DeR threshold is exceeded the instrument
flashes the red LED light every second. If the DE threshold is
exceeded, the red LED light flashes twice every second.
Manufacturer’s preset values are the following:
•
DeR Threshold 1:
1.0 µSv/h
•
DeR Threshold 2:
10 µSv/h
•
De Threshold 1:
10 mSv
•
De Threshold 2: 10 Sv
When the DeR threshold is exceeded that usually means there is
a source of radiation nearby and the general course of action is to
leave the area (the radiation rate drops significantly as the distance
from the radiation source increases). The red DeR alarm will stop
