... <±30% (50KeV—1.3MeV).6,Relative basic error: <±10%(137Cs Source 662 KeV γ Radiation 1msv/h).7,Alarm ... threshold value: 0.5,1.0,2.5,10,30,50usv/h. 9,With accumulated dose memory ... million times storage and erased. 10,Battery voltage indication.Icon shows the battery voltage in the upper right corner ... power. 11,Working environment requirements:Temperature-10 - +50°C Humidity: reach 90% (no condensation) ...