DIN ISO 11665-11:2017-01

Radon is now considered to be the main cause of natural radiation exposure to humans. The UNSCEAR report (2006) suggests that worldwide radon causes about 52% of the global mean exposure from natural radiation. The radiological effect of isotope 222(48%) is far more significant than that of isotope 220(4%), while isotope 219 is considered negligible. Therefore, in this part of the DIN ISO 11665 (VDE 0493-1) series of standards, the term radon refers only to radon-222. Radon-222 activity concentration in soil can be measured by point measurement, continuous or integrating measurement methods with active or passive sampling of soil gas (see DIN ISO 11665-1 (VDE 0493-1-6651):2013-05). In the case of point measurements, the sampling of the soil gas is active. On the other hand, integrating and continuous methods involve passive sampling. This standard describes general guidelines for sampling techniques that are either passive or active by means of short-term, continuous or integrating in situ measurement of the radon-222 activity concentration of soil gas. The detection methods are described in DIN EN ISO 11665-5 (VDE 0493-1-6655):2015-11 and in DIN EN ISO 11665-6 (VDE 0493-1-6656):2015-11. The measurement methods are applicable to all soil types and are defined by using the measurement results while taking into account the expected value of radon-222 activity concentration (phenomenological observation, definition and verification of reduction measures and so on). The responsible committee is DKE/GUK 967.2 "Aktivitätsmessgeräte für den Strahlenschutz" ("Radiation protection instrumentation") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.