Task 1.2: Comparison of existing radon gas primary standards at European NMIs/DIs in the few kBq range

The aim Task 1.2 is to organise, undertake and complete two CCRI(II) comparisons to compare the results of 222Rn and 220Rn measurements made using the existing radon gas primary standards at different European NMIs/DIs in the few kBq range.
The last comparison of radon activity concentration under the auspices of CCRI (EUROMET.RI(II)-S1.Rn-222) was undertaken in Europe in the early 2000s and the data is more than 10 years old. It is, therefore, opportune to undertake two new comparisons of NMI/DI capabilities for 222Rn and 220Rn in the range of a few kBq to assure the quality of these calibration facilities. This task is standalone and complementary to other tasks in this WP and independent of other tasks in the project.