The CoMo-170 is a powerful, mobile and battery or accumulator operated nuclear contamination monitor for highly sensitive nuclide-related measurement of surfaces for α-, β- and γ-contamination when handling ionizing radiation. The one-hand measuring system has a detector area of 170 cm² and automatically detects whether α-radiation is present. The measured value display is optionally pulses per second (Ip/s) or nuclide-related in Becquerel (Bq) and Bq/cm².