Uploaded August 2026 | Updated September 2026, 3 weeks ago
I thought it would be interesting to try detecting naturally occurring radon gas. Granite areas often have some radon because of the uranium content, but radon itself is tricky—it’s a gas, it doesn’t hang around long, and it emits alpha radiation that’s hard to pick up directly.
So instead, I went after the daughter products. When radon decays, it produces solid isotopes like Polonium‑218 and Polonium‑214. These stick to dust, which means you can trap them on a filter paper. Both isotopes emit alpha particles at different energies, so if my detector sees those distinct alpha pulses, that’s a pretty clear sign that radon was in the air.
My setup digitises each pulse into a sound level representing its energy, and ideally, I’d calibrate it properly. Even without calibration, the activity I recorded strongly supports the presence of radon decay products. The software use uses the PC sound channel for data collection, Pulse Recorder and Analyser, it was written by Marek Dolleiser and is handily available free to download.
I thought it would be interesting to try detecting naturally occurring radon gas. Granite areas often have some radon because of the uranium content, but radon itself is tricky—it’s a gas, it doesn’t hang around long, and it emits alpha radiation that’s hard to pick up directly.
So instead, I went after the daughter products. When radon decays, it produces solid isotopes like Polonium‑218 and Polonium‑214. These stick to dust, which means you can trap them on a filter paper. Both isotopes emit alpha particles at different energies, so if my detector sees those distinct alpha pulses, that’s a pretty clear sign that radon was in the air.
My setup digitises each pulse into a sound level representing its energy, and ideally, I’d calibrate it properly. Even without calibration, the activity I recorded strongly supports the presence of radon decay products. The software use uses the PC sound channel for data collection, Pulse Recorder and Analyser, it was written by Marek Dolleiser and is handily available free to download.
