There are three detection modes: Real-time dose, average dose and cumulative dose to meet your different needs. Real Time Dose (REAL): Update once per second to quickly display the true value of each moment, characterized by large fluctuations and high correspondence with the sensors' detection results. The real-time value will be tested and displayed automatically after booting without any operation. (unit: ups or h) Average Dose (AVG): Record the total dose received over a period of time and convert it to the average display, which features low fluctuation and convenience to check the background value of the environment and the low-radiation environment. Press the M button to recalculate the mean. (unit: ups or h) Cumulative dose (ACC): That is, add up all the detected doses, and the data will not be lost after the shutdown, and historical data will continue to be accumulated after the reboot, and there will be a long-term cumulative sum value. You can press the L button and R button at the same time to clear the cumulative value. (Unit: msv or h) Portable Size: The small size of this tool is very convenient for your daily use. You can carry it in your tool bag without taking up too much storage space. Wide Applications: This nuclear radiation detector can be used in nuclear physics, environmental monitoring and industrial fields. Specifications: Material: ABS Color: Black,White Detectable types: , Y, X rays Diaplay mode: LCD Screen and Backlight Energy ranges: 20kev-3.0 Mev 30 percent (137Cs-) Sensitivity: 80cpm or sv or (Co-60) Test accuracy: 0.01 sv or h Real time ranges: 0-99.99 sv or h Cumulative ranges: 0-99.999 msv Real Time Error: 10 percent Mean error: 3 percent Power supply: 3 x 1.5V batteries or 1.2V rechargeable batteries (NOT INCLUDED) Battery time: 4 hours Overall size : 106x70x30mm or 4.17x2.75x1.18 inch Package Weight: 131.5g or 4.6oz Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.