| 摘要 |
β-particles from the decomposition of radon daughters RaB and RaC are detected from at least an essentially confined, free room air volume via the calculation of detector pulses during a set period of time. Detection is carried out at such a distance from surfaces in the room, whereupon the radon daughters can be deposited so β radiation from the decomposition of deposited radon daughters are essentially undetected. During detection, the deposit of radon daughter at the opening to the detector is prevented; especially on the window of the detector by having a radium-absorbent and radium disposing cover go past the opening. A measurement test value is calculated based on an activity-representative pulse count N, obtained through calculation. In particular, a measurement test value EEC' = k1 N(RaB) + k2 N(RaC) + k3 where k1, k2 and k3 are determined via calibration at known radon daughter contents during the utilisation of linear multiple regression.<IMAGE> |
