What percentage of annual tests should be blanks to ensure accuracy?

To maintain accuracy in radon measurement testing, it is essential to include a certain percentage of blank tests. Including blank tests in the annual testing schedule serves several purposes: they help identify any background levels of contamination in the testing process, ensure that equipment is functioning correctly, and confirm the validity of the testing results.

A benchmark of 5% is generally recognized as an effective standard for the percentage of annual tests that should be blanks. This level of blank testing provides a reliable measure for assessing the integrity of the measurement environment and the testing methodology. The rationale behind this figure is rooted in ensuring that the results obtained from the actual tests can be trusted and are not influenced by external factors or contamination.

While lower percentages may provide some level of monitoring, they might not adequately capture incidental contamination or equipment issues. Conversely, higher percentages may be impractical or unnecessarily burdensome. Therefore, the practice of using 5% blank tests strikes a balance between maintaining rigorous quality control and practical application in the field.