radon measurement period
https://getactivesubslabmag.clarionvale.com/posts/why-active-sub-slab-depressurization-works-for-radon-mitigation-in-st.-louis
During the radon measurement period, we placed small detectors in the basement and first-floor rooms to track gas levels over three months. The winter season usually traps more radon inside, so timing matters. We checked the devices weekly, noting any spikes after heavy rain or snow. The final report showed safe averages, but we still installed a simple vent system for peace of mind.