Measurement of indoor air

Measuring method

Radon levels in indoor air is measured with so-called track film detectors that are roughly as big as a snuffbox. Track film detectors are passive detectors, which means that they do not emit any signals. In fact, such detectors have no electronic components and consist only of plastic. They don’t need to be switched on as measuring starts when they are removed from the airtight aluminium sachet in which they are supplied and measuring ends when they are put back into the sachet and sent to our laboratory for analysis.

A measuring kit for measuring radon in indoor air contains detectors, measuring instructions and a measuring protocol. The price includes the analysis and measurement report. Payment is against an invoice with comes with the measuring kit (30 days net).

Long-term measuring

If a measuring operation in a residence is performed as per the Swedish Radiation Safety Authority’s recommendations, the measured radon gas levels for the residence are given as an annual average value. The recommendations that must be followed in this case are that measuring period must be at least 60 days and that measuring must be performed in the heating period (1 October - 30 April). In addition, a measuring operation must be performed with at least one detector on each floor with rooms with living space. Rooms with living space means for example bedrooms, living rooms, dens or kitchens. Laundry rooms, toilets or showers do not count as rooms with living space. A further requirement is at least 2 detectors per residence. The advantage of having the radon level in your residence expressed as an annual average value is that it is very reliable and easily compared measurement. In addition, the annual average value is the measurement that authorities request, for e.g. if you want to apply for a lower assessed property valuation due to excessive radon levels. Note that measurements in work premises do not produce an annual average value but should nevertheless be performed in a similar way to give reliable values.

Short-term measuring

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

Measuring radon in the ground

The radon level in the ground is measured with ground radon detectors, which are buried in the ground at a depth of approx. 1 m. Measuring 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 protocol. Payment is against an invoice which is sent separately.