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ResourcesGlossary: testing

Short-term test

By Radon411 Editorial TeamUpdated 1 min readHow we research

Short answer

A short-term test is a radon test that stays in the home from 2 to 90 days, depending on the device, and for a minimum of 48 hours. It is the quick first measurement.

What short-term test means

Because radon levels vary from day to day and season to season, EPA says a short-term test is less likely than a to tell you your year-round average radon level.

EPA lists the devices used for it: charcoal canisters, alpha track detectors, electret ion chambers, charcoal liquid scintillation devices and continuous monitors.

How long a short-term test runs, in hours

Each row multiplies days by 24. EPA gives its own example of what a short result can and cannot say: if the average of two short-term tests is 4.1 , there is about a 50 percent chance that the year-round average is somewhat below, or above, 4 pCi/L.

Short-term test lengths in days and hours
TestDaysHours
EPA's minimum for any radon test248
A 7-day charcoal canister, EPA's example of a device that needs longer7168
The longest short-term test902,160

What it means for your home

If a first short-term result is 4 pCi/L or higher, EPA says to follow up with either a long-term test or a second short-term test. If it is more than twice the , take the second short-term test immediately.

Run it under : windows and outside doors closed, except for normal entry and exit, from 12 hours before the test and all through it.

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