WP5: Validation of traceability of European radon calibration facilities

The aim of this work package is to validate the traceability of existing European radon calibration facilities at NMIs/DIs, accredited laboratories, other calibration laboratories and universities over the ranges from 100 Bq/m³ to 300 Bq/m³ and 300 Bq/m³ to 10 000 Bq/m³.
The traceability of measurements plays an important role in many quality systems. The desire to improve and harmonise radon measurements in air arose during the last quarter of the 20th century, as radon activity concentrations in air measured with different radon monitors were found not to be consistent with each other when the monitors were placed in the same environment. As a result, many existing laboratories still look for uniform traceability to a validated primary standard.
In this WP comparisons will be performed, which will allow the operators of radon calibration facilities to reduce the relative uncertainties related to their facilities below 5 % (= 1). These international comparisons will fulfil the need to provide confidence in the capability of European radon calibration facilities in the field of radon activity concentration measurements in air. The traceability of calibrations for radon activity concentration in air measurement to European radon calibration facilities (national or international standards) will be established by using existing primary radon gas standards and the new radon activity standards traceable to primary standards developed in WP1, and two different approaches for validation will be used: The first way is to calibrate the secondary standard devices used by European radon calibration facilities in the same place with traceability to the new radon gas standards. The other way of validation is for one reference device calibrated with a primary radon gas standard to be shipped to European radon calibration facilities for a comparison with their existing secondary standards. Task 5.1 will identify suitable European radon calibration facilities to participate in the validations to be undertaken in Task 5.2 and Task 5.3. In Task 5.2 intercomparisons will be conducted using a calibrated instrument to validate the traceability and performance of European radon calibration facilities in the range from 300 Bq/m³ to 10,000 Bq/m³, whilst in Task 5.3 the traceability and performance of European radon calibration facilities will be validated using a reference device calibrated in a stable reference atmosphere with traceability to a primary standard in the range from 100 Bq/m³ to 300 Bq/m³.

Task 5.1: Selection and evaluation of European radon calibration facilities for validation of traceability

Task 5.2: Validation of traceability, performance and precision of European radon calibration facilities

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