external exposure facility STUK website Paul Schofield The Radiation Metrology Laboratory (DOS) at STUK (Radiation and Nuclear Safety Authority, Finland) maintains the Finnish national standard for ionising radiation and provides calibration and irradiation facilities covering gamma, X-ray, alpha, beta and neutron radiation qualities, with dose rates from 700 nGy/h to 40 Gy/h. The laboratory is accredited to ISO 17025, is a member of CIPM MRA and participates in regular EURAMET intercomparison measurements and external audits. It is also a member of the IAEA/WHO SSDL network. Located at STUK.