Task 5.3: Validation of the traceability of European radon calibration facilities at stable radon atmospheres in the range from 100 Bq/m3 to 300 Bq/m3

The aim of this task is to validate the traceability of the European radon calibration facilities by comparison of the secondary standards used by European radon calibration facilities in the range from 100 Bq/m³ to 300 Bq/m³ to the reference device calibrated in a reference radon atmosphere traceable to a primary standard.
The validation exercise will be organised, scheduled and a reference laboratory selected. The European radon calibration facilities will send their secondary standards which are used for the calibration of the end-user devices to the reference laboratory, which will compare the secondary standards against a reference device calibrated in WP1 and tested in WP1 in the range from 100 Bq/m³ to 300 Bq/m³. The reference laboratory will evaluate any deviations in the existing calibration of the secondary standard. A report will be produced for each calibration by the reference laboratory detailing the results and any deviations, and the reports then sent to the relevant European radon calibration facilities. A validation report on the traceability of primary and secondary radon calibration facilities in Europe will be produced together with a guideline and recommendations on metrologically sound calibration and measurement procedures for the determination of radon concentration in air.