13
Normal operation mode and alarms
After PM1904A is charged and disconnected from the power
supply 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 those
measurements to preset thresholds.
If the thresholds are exceeded, a red light will flash on the LED. A
red LED light flashing every second indicates that the DER
threshold was exceeded; a red light flashing twice every second
indicates that the DE threshold was exceeded.
The manufacturer’s preset values are follows:
•
DER Threshold 1: 1 µSv/h
•
DER Threshold 2: 10 µSv/h
•
DE Threshold 1: 1 mSv
•
DE Threshold 2: 5 mSv
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
after background radiation drops below the preset threshold.
When the DE threshold is exceeded it doesn’t necessarily mean
that there is a radiation source nearby. Moreover, the red DE alarm
Summary of Contents for PM1904A
Page 1: ...QUICK START OPERATION GUIDE Electronic Personal Dosimeter PM1904 POLISMART II...
Page 25: ...27 Figure 7 History mode on Android OS mobile devices...
Page 27: ...29 a b Figure 9 World Map for Android OS mobile devices...
Page 29: ...31 Figure 10 Window of the applications Settings mode...
