Measurement of indoor air

Measuring method

Radon levels in indoor air is measured with so-called track-etch detectors, roughly the size of a snuffbox. Track-etch detectors are passive detectors, meaning they do not emit any signals. In fact, such detectors have no electronic components and are made entirely of plastic. The measurement starts when they are removed from the airtight aluminum sachet in which they are supplied. Measurement ends when they are put back into the sachet, ready to send in to our laboratory for analysis.

A measuring kit for measuring radon in an indoor environment contains detectors, measuring instructions and protocols. The price includes the analysis and measurement report.

Long-term measuring

A radon measurement performed per the DSA's recommendations gives the measured radon gas levels for the residence as an annual average. Measuring operations must be performed during the heating period that runs between October 15th and April 15th, with a minimum period of 60 days and nights. The measurement must be performed on all floors with rooms with living space (i.e. bedroom, living room). If the residence is on one floor, two radon detectors are placed in two different rooms with living space. If the residence has two or more floors, a radon detector is placed on each level. Another requirement is at least 2 detectors per residence. Having the radon measurement expressed as an annual average level gives reliable and easily comparable measurements. In addition, the annual average value is government mandated. If you want to apply for a lower assesment property valuation due to excessive radon levels. Note that measurements at work premises do not produce an annual average value, but should still be performed in a similar manner to give reliable results.

Short-term measuring

Indicative short-term measuring can be performed if time is short, or as a quick check to see if performed radon mitigation has been effective. Measuring must span over at least 7 days (longer measuring periods give more accurate measurement values). The results are in some cases uncertain, and should therefore be interpreted accordingly. Note that indicative short-term measurement NEVER gives an annual average value. Indicative measurement should always be followed up by long-term measurements.

Measuring radon in the ground

Radon levels in the ground are measured with ground radon detectors, buried approximately 1 meter below ground. Measurements must span over 4-5 days. We recommend two ground radon detectors for testing of each specific house location. Ground radon detectors are supplied with instructions for use and measuring protocols.