Are Home Radon Monitors Accurate? What Official Sources Say

What makers claim

Manufacturers publish their own figures. Airthings, for example, lists the Corentium Home 2 as accurate within 10% after 7 days at 5.4 pCi/L,⁠² and its View monitors at about 10% after 7 days and about 5% after 2 months at the same level.⁠³ These are the maker’s statements, not independent tests.

What official guidance says

Check results with an approved test. CRCPD says to verify a monitor’s results by hiring a certified or licensed radon professional or using an approved test kit.⁠¹
Keep checking over time. Monitors may lose accuracy and reliability over time, so CRCPD says to verify radon levels periodically using an approved method.⁠¹
Not for mitigation decisions. CRCPD says consumer monitors are not for making radon mitigation decisions; long-term testing is advised.⁠¹
Never for a home sale. CRCPD says consumer monitors should never be used in real estate transactions.⁠¹ For a sale, the Health Department points to short-term test kits.⁠⁴
At least 48 hours. The minimum length for any radon test is 48 hours.⁠¹
If it reads high: the EPA says you may wish to use a long-term test or consult a radon professional.⁠⁵

Consumer vs. professional monitors

Certified radon professionals use devices on approved lists. As of October 17, 2026, NRPP’s and NRSB’s lists include Airthings’ professional Corentium Pro, but not its consumer models.⁠⁶⁷

So what’s a monitor good for?

Watching levels change day to day, between lab tests. The Health Department’s recommended way to learn your home’s typical level is a long-term test of 3 to 12 months, ideally including a heating season,⁠⁴ and its Lab sells that kit for $25.⁠⁸ See Airthings’ three monitors compared.

The recommended test, plus a monitor if you want one

Order the Health Department Lab’s long-term kit for $25⁠⁸ and leave it in place for 3 to 12 months, ideally including a heating season.⁠⁴

Want to see levels day to day? A digital monitor measures and records radon continuously while it has power.⁠⁹ Use it alongside the lab test, not instead of it: CRCPD says to check a consumer monitor’s results with an approved test.⁠¹⁰

Order the $25 long-term kit See Airthings monitors Affiliate link

If you buy through the Airthings link, Vermont Radon may earn a commission at no extra cost to you. How we make money

Enter vtradon-10OFF for 10% off at checkout. Airthings ships only within the US.

The state lab kit is not an affiliate link. To order by phone, call 802-338-4736 or 800-660-9997.⁠⁴

Common questions