The clearance counter is equipped with 2 large-area plastic scintillation detectors. The measuring chamber (approx. 450 x 450 x 550 mm) is shielded on all sides with 5 mm low-activity lead to guarantee a low background. In a measurement time of 30 s (BG-measuring time 300 s) a detection limit of < 100 Bq is reached, related to Co-60, located in the center of the measuring chamber (75 Bq of Co-60 at 30 sec. measuring time, 100 sec. background and 50 nSv/h dose rate).