Exposimeter (track etch detectors)
Exposimeters are a simple and inexpensive solution to measure the indoor radon activity concentration.
Exposimeters can be purchased online from by using the order form.
For more information about the indoor measurement procedure and to get to the online order form, please click here. We apologize for providing only a German version of the order form.
Exposimeters are a world-wide well-established procedure for measuring indoor radon concentrations. Due to convenient handling and low costs this integrating long-term measuring procedure is suitable for extensive measuring campaigns as well as for private customers at home. The measuring range of approx. 15 Bq/m3 up to over 5.000 Bq/m3 enables the accurate determination of all radon concentrations usually occurring in residential buildings.
The detector itself - a plastic film consisting of a polycarbonate foil (approx. 1 to 10 cm2 in size, approx. 0.1 to 1 mm thick) - is located inside the exposimeter housing. Air containing radon diffuses through the housing into the measuring chamber; radon decay products, dust and humidity are retained here. In addition, the sufficiently large diffusion resistance prevents the intrusion of thoron (Rn-220; half-life: approx. 55 seconds). In the measuring chamber radon decays emitting alpha particles into its so called radon daughters. These short-lived decay products are alpha-emitters too. The alpha particles create microscopic tracks in the film, which are counted in the laboratory. Afterwards, a specific radon concentration based on the number of the tracks, the size of the detector and the exposure time is calculated.
The exposimeter is very easy to handle. It is working without an external or internal power supply. It is not necessary, to change any settings or to read off any values. It is recommended, to place two exposimeters in each house: One of them in the main living room in the ground floor, the other one in the basement.
We offer exposimeters for long-term measurements (3 months until 1 year) and for short time measurements (7 to 10 days).
The decision for planning of remediation measures to reduce the radon concentration in buildings should be exclusively based on long-term measurements.