Radon inspection can be done using either passive or active devices. When performing a short-term inspection, use passive devices such as charcoal canisters, alpha track detectors, liquid scintillation detectors and electret ion detectors. Long-term inspections require active devices. Both approaches are important when securing an area from radon's radioactive particles.
Charcoal scintillating devices and canisters absorb the radioactive particles. Radon products are converted to light in a liquid scintillating medium and counted by a sodium iodide counter or a scintillating detector. The alpha track devices attract and retain alpha particles using a plastic film. The alpha particles etched on the film are counted in the laboratory. Additionally, use electret ion detectors that have a statically charged Teflon disc. Ions generated from radon decay lose their electric charge when they strike the Teflon disc. The reduced charge is measured, and the radon level quantified.
Radon testing can also be done using active devices, such as continuous working level monitors and continuous radon monitors. Unlike passive devices, active devices detect and record the radon and its products continuously using electricity. These devices require professional expertise for effective operation and accurate results. Place the device in a room that is frequently occupied, such as a bedroom, dining room or family room.