This app requires smartphone with camera, that can be covered so no light hits the sensor - black or aluminium tape works fine.After the sensor is covered, the app detects "hot pixels" caused by ionizing radiation, and is able to provide precise CPM (counts per minute) number and, after calibrating against well-known detector estimated dose rate in uSv/h.Be aware that the modern phone cameras have the sensor really small (a couple of square millimeters) and not much sensitive, so you need quite "hot" source to get measurable results. A large piece of high quality uranium ore works usually fine.The application currently supports averaging over two timeframes, and graphing data.Disclaimer: even though the principle of the operation is solid and it has been proven to work on multiple devices, this application is not intended as a replacement for a well-calibrated Geiger counter, dosimeter or another radiation detector. This application should not be used instead of proper meter for radiation safety or where life, health or property could depend on the risk.
Camera-based Geiger Counter
