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An electret passive environmental 222Rn monitor based on ionization measurement
P Kotrappa1, J C Dempsey, J R Hickey
1Plastic Casting Inc., Olean, NY 14760.
Health Physics
|January 1, 1988
Summary
The electret passive environmental radon monitor (E-PERM) accurately measures radon exposure by collecting ions on an electret. Its sensitivity is suitable for both short-term and long-term radon monitoring in homes.
Area of Science:
- Environmental Science
- Radiation Detection
Background:
- Electret dosimeters are established for X and gamma radiation measurement.
- Radon (222Rn) is a significant indoor air pollutant requiring accurate monitoring.
Purpose of the Study:
- To introduce and characterize the electret passive environmental 222Rn monitor (E-PERM).
- To assess the E-PERM's sensitivity and suitability for various radon exposure durations.
Main Methods:
- Utilized electret dosimeters adapted for 222Rn gas detection.
- Designed E-PERM devices with varying chamber volumes and electret thicknesses.
- Measured surface potential drop on the electret as an indicator of integrated radon exposure.
Main Results:
- A 220-mL E-PERM with a 0.23 cm electret showed a 2.5 V drop for 37 Bq m-3 d.
- A 40-mL E-PERM with a 51-micron electret yielded a 2.6 V drop for 37 Bq m-3 y.
- Electret surface potential stability was confirmed under varying humidity conditions.
Conclusions:
- The E-PERM is a sensitive and reliable tool for both short-term (weekly) and long-term (yearly) 222Rn monitoring.
- The ion collection efficiency remains consistent across a wide range of electret surface potentials and humidity levels.
- E-PERM technology offers a stable and effective method for assessing indoor radon exposure.
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