Adsorption of 222Rn by Open-faced and Diffusion-barrier Canisters at Different Conditions of Temperature and Humidity

Luetzelschwab, John W.; Hastings, L.; Ellis, Stephanie

doi:10.1097/00004032-199401000-00009

Cited by 17 publications

(7 citation statements)

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“…EPA set the values for these parameters in ranges believed typical of U.S. homes, e.g., 16 -29°C (60 -85°F) temperature range. Both temperature and relative humidity are well known environmental factors that may influence the testing results of charcoal-based short-term radon test devices (George 1984;Prichard and Marien 1985;Ronca-Battista and Gray 1988;Pojer et al 1990;Luetzelschwab et al 1994).…”

Section: Discussionmentioning

confidence: 99%

Blind Testing of Commercially Available Short-Term Radon Detectors

Sun¹,

Budd

McLemore

et al. 2008

Health Physics

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A sample of commercially available, charcoal adsorption type, short-term radon detectors was blind tested under controlled laboratory conditions in order to obtain a "snapshot" of the accuracy and precision of the detectors. The results of the controlled exposures were then compared to a previous field study of the same type of commercially available radon detectors. Radon detectors, purchased from seven different commercial vendors, were exposed to a reference (222)Rn gas concentration at the U.S. Environmental Protection Agency's (EPA) Radon Chamber located at the Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada. EPA Test 1 was performed under a controlled simulated field exposure paralleling, to the extent possible, the previous actual field exposure conditions. A second controlled exposure, EPA Test 2, was performed under a relatively steady state of (222)Rn gas concentration, at the same temperature, but a more moderate relative humidity. In the previous field setting evaluation of detectors, five out of six companies tested did not pass the accuracy guideline (all individual relative errors < or =25%) established during the EPA's former Radon Measurement Proficiency Program (EPA-RMPP). As compared to the field test, the detectors in this study generally exhibited better accuracy and precision. Not surprisingly, it appeared temporal fluctuations in radon concentrations and increased humidity had a negative influence on the accuracy and precision of detectors for some companies. The inability of three out of seven companies to meet former EPA-RMPP guidelines for accuracy, even under ideal exposure conditions (constant temperature, humidity, and radon concentration), highlights the importance of blind testing commercially available radon detectors. Furthermore, the consistent over-reporting or under-reporting trends in the overall results for all three tests suggest a potentially widespread systematic bias for the individual companies that merits further investigation. It is unknown if this one-time "snapshot" represents the overall reliability of commercially available charcoal-based radon detectors. Nonetheless, the findings suggest the need for improved vigilance to assure that the public can rely on commercially available radon detectors to make an informed decision whether or not to perform additional testing or to mitigate.

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Section: Discussionmentioning

confidence: 99%

Blind Testing of Commercially Available Short-Term Radon Detectors

Sun¹,

Budd

McLemore

et al. 2008

Health Physics

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“…The concentration of radon can be determined either by the detection of alpha particles emitted by radon and its progeny or by the detection of gamma rays emitted by its decay products. Alpha track detectors are normally used for estimating the average radon concentration over long-term periods, while for short-term averages the activated charcoal method is usually employed (Bigu 1986;Cohen and Nason 1986;Scarpitta and Harley 1991a and b;Arafa et al 1994;Luetzelschwab et al 1994). Corresponding author:Hala Mohammed Abd El-Ghany.Email:hala.m.bakeer@gmail.com…”

Section: Introductionmentioning

confidence: 99%

“…As the charcoal adsorbs the water, it has fewer sites available for radon atoms, or water can displace radon that has already been adsorbed. In addition, temperature affects the ability of charcoal to adsorb radon (George 1984;Prichard and Marien 1985;Ronca-Battista and Gray 1988;Pojer et al 1990;Luetzelschwab et al 1994).…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature and humidity on the performance of Charcoal CanisterPassive Rn detectors

Mahmoud

Arafa

Ashry

et al. 2016

Journal of Scientific Research in Science

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The dependence of radon adsorption on the temperature up to 35 °C was studied for 4" open face (OF) charcoal canister at different values of relative humidity using a radon calibration chamber with variable and controlled radon concentration, humidity, and temperature which was previously constructed. Sets of calibration factor (CF) and adjusting factor (AF) curves were established at 20, 25, 30, and 35 °C and,different humidity (RH%). These curves are used to extend the use of open-faced charcoal canisters for higher temperature and humidity applications. The optimum exposure time to achieve the best detection accuracy was estimated between 2 and 4 days depending on relative humidity. The open-faced canisters havehigher efficiency of radon absorption at low temperature.

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“…The effect of humidity (Ronca-Battista and Gray, 1988;Scarpitta, 1992) and temperature (El Samman et al, 2002;Luetzelschwab, 1994) on charcoal canisters and PicoRad detectors have been extensively investigated in the past. Among others, Iimoto (2005Iimoto ( , 2008 showed that PicoRad measurements done in a high relative humidity environment, such as radioactive spas and other ground areas (mines, caves, tunnels, etc.…”

Section: Introductionmentioning

confidence: 99%