scope:

This standard is applicable to equipment intended for continuous or sequential measurement of alpha-emitting transuranic aerosols in gaseous effluents discharged to the environment. It is applicable to equipment designed to fulfil the following functions: - the measurement of the concentration of airborne alpha-emitting particles present in gaseous effluents in the form of transuranic aerosols; - the actuation of an alarm signal when either a predetermined concentration or a predetermined activity of transuranic nuclides is exceeded. This equipment is intended for the measurement over a wide range of activity associated with alpha-emitting transuranic aerosols, including very small quantities in the presence of a much larger natural alpha background. The daugthers of ²²²Rn (radon) and ²²⁰Rn (thoron) constitue the natural alpha background.