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.