What are the most commonly used radon testing methods?
There are two main methods used to test for radon gas and radon daughter products. The most popular involves a “passive” device such as an activated charcoal test kit that collects radon gas atoms or an alpha track device that has a small strip of special plastic that is “marked” when hit by radon’s alpha particles. “Passive” devices are later “counted” in a laboratory to give you your result. Another passive device called an electret has a plastic disc with a static charge. Electrets are used only by professional radon inspectors because of the expertise required and the expensive equipment needed for analysis. The other main method is the use of an “active” device called a CRM (continuous radon monitor). These are mostly used by professional radon inspectors for short-term (48 hours) radon testing during a real estate transaction. There are many different models of CRMs, but they all require some formal training in order to be used properly. The biggest differences between passive an
