What method is used to measure radon concentrations with alpha-track detectors?

Alpha-track detectors measure radon concentrations by relying on the density of tracks left by alpha particles emitted during the decay of radon gas. When radon gas decays, it releases alpha particles that collide with the surface of the detector, creating damage tracks. Over a designated exposure period, the alpha particles leave a series of tracks proportional to the concentration of radon in the air during that time. After the detection phase, the number of tracks is counted under a microscope, and this count is used to calculate the radon concentration in the environment where the detector was placed.

This method is effective for determining long-term radon exposure levels, as it integrates the alpha emissions over time, unlike other methods which may focus solely on immediate readings or other parameters.