radon system follow-up test 2

https://getbuiltdepstandardspro.fairmontdigest.com/posts/why-radon-mitigation-systems-must-be-built-to-dep-standards

A follow-up test for a radon system checks that the mitigation setup is still effectively lowering radon levels. We place detectors in the same spots as the original test, typically in the livable areas, and run them for a minimum of 48 hours to get a reliable average. Depending on your region and season, we'll schedule this test a few months after installation, or if you've made any foundation modifications, just to ensure the system continues protecting your indoor air quality.