This environmental radiation is emitted continuously, day and night, from various objects and substances in the natural world and our living environment. PA-1000 "Radi" environmental radiation monitor makes it easy for non-specialists to measure even minute levels of gamma rays as one of the type of environmental radiation. One of the feature from this unit is high performance detection with a CsI (Tl) scintillator where it can measure radiation levels ranging from normal natural radiation to levels 100 to 200 times that intensity. Even non-specialists will find it easy to measure radiation of 0.001 - 9.999 µSv/h