Earlier this year, Vladimir Peskov, a physicist from CERN Laboratory in Switzerland, unveiled the first radon detector inexpensive enough to install by the hundreds. Standard scientific radon detectors inject air samples into a closed chamber of argon gas in an electric field. Radon decays into radioactive particles that alter the charge of the argon, and the detector reads this change to determine radon levels. This closed system eliminates other interactions from being read as radon, but it costs $15,000. Peskov increased the gradient of the electric field in the chamber of his device, allowing it to identify subtler changes as air breezes through it. It costs $60, he says, and it works as well as the more expensive models.