Glossary

When measuring radon via its follow-up nuclide concentration in the air, a conversion formula is required. Here, the equilibrium equivalent radon concentration is first determined. The equilibrium equivalent radon concentration, also called EEC, is defined as a hypothetical radon concentration under equilibrium conditions. There this equilibrium between radon and its secondary nuclides is hardly reached in the interior because the short-lived follow-on nuclides quickly attach to surfaces and are thus removed from the air, the EEC is always lower than the radon concentration. The following simple conversion leads to the approximate radon concentration CRn: CRn [Bq / m3] = EEC [Bq / m3] / F If no precise information is available, the equilibrium factor F can be set to a value of 0.4 indoors be set.