Activated Carbon Open
AccuStar PicoCan Open Face Charcoal Canisters
AccuStar Labs offers the PicoCan 275 and PicoCan 400 open face charcoal canister for your short-term radon testing needs. Radon test kits using the PicoCan Model 275 and the PicoCan Model 400 include the device, instructions for its use, data sheet for notation of exposure information, a return mailer and a report of laboratory analysis. Single packaged tests kits contain one test canister and are best used as an initial screening test. Double test kits contain two test canisters and are designed to be used in real estate transactions following the US EPA simultaneous testing protocol. They can also be used to measure the "stack effect" by placing one canister on the lowest level and another on a higher level. Test canisters packaged in bulk are available for testing large buildings and schools.
The PicoCan Model 275 and the PicoCan Model 400 are open face activated charcoal canister radon sampling devices that consist of a metal canister measuring 2 ¾" (PicoCan 275) or 4" (PicoCan 400) in diameter, and 1" deep. The PicoCan 275 canister contains 25 grams of activated charcoal. The PicoCan 400 canister contains 75 grams of activated charcoal. In both models, the charcoal is held in place by a metal screen. The PicoCan 275 canister is closed with a metal lid and sealed with vinyl tape. The PicoCan 400 canister is closed with a metal lid that has a circular piece of foam material attached to the inner surface. The PicoCan 400 is also sealed with vinyl tape. Both devices are designed to be exposed in an indoor environment for a minimum of 48 hours and a maximum of 96 hours, with a recommended exposure of 48 hours. A complete calibration for each device has been developed from devices that have been exposed in a radon chamber operated by Bowser-Morner in Dayton, OH. Exposures have included different radon concentrations, durations and relative humidity.
To begin the radon measurement the user removes the tape and the lid and sets the canister in a room for the chosen exposure period. The user writes the start date and time, ending date and time and test location information on a data sheet. During the exposure period the device is left open and undisturbed, so that radon-laden air can diffuse through the metal screen and adsorb onto the activated charcoal.
The user places the device in accordance with one or more the following US EPA and/or State radon measurement protocols:
- Indoor Radon and Radon Decay Product Measurement Device Protocols
(EPA 402-R-92-004, July 1992) revised
- Protocols for Radon and Radon Decay Products Measurement in Homes
(EPA 402-R-93-003, June 1993)
- Radon Measurement in Schools - Revised Edition
(EPA 402-R-92-014, July 1993)
At the end of the chosen exposure period, the user replaces the lid on the device and reseals the edge with the vinyl tape. The device must be returned to the lab for analysis within 8 days from the date of closure.
The user also follows standards of practice for quality assurance as outlined in:
- EPA National Radon Proficiency Program Guidance on Quality Assurance
In the laboratory, the closed device is placed on a gamma detector. Gamma emissions from the decay of radon adsorped on the charcoal are counted. A calibration factor accounting for exposure time and decay time is used to calculate the radon concentration. A correction factor is applied for any weight gain from moisture absorbed in the charcoal during the exposure period. The average radon concentration over the exposure period is reported in picoCuries per liter.