Types of Radon Testers

Radon is a colorless, odorless radioactive gas that occurs naturally and can cause cancer over long periods of exposure. In order to prevent exposure, several types of radon detectors have been created which either detect radon gas directly or register the by-products of radon's radioactive decay. Active radon detectors are powered devices which test for radon at predetermined integers. Passive devices require no power source and trap evidence of radon to be analyzed in a laboratory.

Alpha Track Detectors

• Alpha track detectors use a small sheet of polycarbonate plastic film, which will be etched by collisions with microscopic alpha particles. After exposure, the film is chemically treated to reveal the markings left by the alpha particles, which can be counted to determine the concentration of radon.

Electret Ion Chamber

• Using a charged teflon disc to detect radon decay, the electret ion chamber periodically covers and uncovers the disc at regular intervals to take readings. If ions generated from radon decay strike the disc, its electric charge is reduced. After exposure, any reduction in the charge can be measured to determine the level of radon present.

Charcoal Liquid Scintillation Detector

• The charcoal in a liquid scintillation detector absorbs radon or its by-products and can then be taken to a laboratory for examination. Either by using a sodium iodide counter to detect radioactive particles emitted from the charcoal or by converting them to light in a liquid scintillation medium, observers are able to count the particles to determine the amount of radon present.