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Proficiency test of commercial radon monitors for low level radon exhalation measurements in chambers with air exchange

  • Compared to the designated European upper reference level of 300 Bq m-3 for indoor radon concentrations, the contribution of building materials appears to be low. Taking into account the recommended limit of 100 Bq m-3 by WHO as well as the increased dose conversion factor, the contribution of building products is quite relevant, especially at low air change rates. Therefore in Germany a maximum contribution of building materials to the indoor radon concentration of 20 Bq m-3 is discussed. Because measurements of low concentrations are associated with high uncertainties, radon exhalation rates are often determined in chambers without air exchange and indoor conditions are extrapolated. This study investigated the suitability of direct low level radon measurement under simulated indoor conditions with commercially available instruments, based on the preliminary EU standard for the determination of the emission of volatile organic compounds (VOC) from building materials in testCompared to the designated European upper reference level of 300 Bq m-3 for indoor radon concentrations, the contribution of building materials appears to be low. Taking into account the recommended limit of 100 Bq m-3 by WHO as well as the increased dose conversion factor, the contribution of building products is quite relevant, especially at low air change rates. Therefore in Germany a maximum contribution of building materials to the indoor radon concentration of 20 Bq m-3 is discussed. Because measurements of low concentrations are associated with high uncertainties, radon exhalation rates are often determined in chambers without air exchange and indoor conditions are extrapolated. This study investigated the suitability of direct low level radon measurement under simulated indoor conditions with commercially available instruments, based on the preliminary EU standard for the determination of the emission of volatile organic compounds (VOC) from building materials in test chambers. Measurements are possible with a relative uncertainty ranging from 7 to 18 %. Four major problems were identified: 1. Detector sensitivity: Two of four instruments were identified to determine low radon concentrations in a sufficiently short measuring time. 2. Thoron discrimination: Thoron was discriminated by aging the sampled air in a hose before the detector. 3. Sampling setup: An external chamber measurement was feasible as long as all main system parts were under slight overpressure. 4. Blank value: For VOC-emission testing ambient air, conditioned by filtration and sorption, is used to generate an air exchange. Regarding radon, this treatment is non-effective. If all instrument background levels have been characterized, the blank value must be measured with a second detector in parallel.zeige mehrzeige weniger

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  • Hofmann et al-2016-Proficiency test of commercial radon monitors for low level radon exhalation measurements in chambers with air exchange-Presentation.pdf
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Metadaten
Autoren/innen:Michael Hofmann
Koautoren/innen:Matthias Richter, Oliver Jann
Dokumenttyp:Vortrag
Veröffentlichungsform:Präsentation
Sprache:Englisch
Jahr der Erstveröffentlichung:2016
Organisationseinheit der BAM:4 Material und Umwelt
4 Material und Umwelt / 4.2 Materialien und Luftschadstoffe
DDC-Klassifikation:Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Sanitär- und Kommunaltechnik; Umwelttechnik
Freie Schlagwörter:Building materials; Radon exhalation; Radon measurement; VOC emission test chamber
Themenfelder/Aktivitätsfelder der BAM:Umwelt
Umwelt / Umweltschadstoffe
Material
Material / Materialien und Stoffe
Veranstaltung:8th International Conference on Protection against Radon at Home and at Work
Veranstaltungsort:Prague; Czechia
Beginndatum der Veranstaltung:12.09.2016
Enddatum der Veranstaltung:15.09.2016
Verfügbarkeit des Volltexts:Volltext-PDF im Netzwerk der BAM verfügbar ("Closed Access")
Datum der Freischaltung:21.09.2016
Referierte Publikation:Nein