Which measurement device is commonly used for time-integrated radon measurements?

The Alpha Track Detector is commonly used for time-integrated radon measurements because it captures the alpha particles emitted by radon decay over an extended period, typically ranging from a few months to a year. This type of detector contains a film that becomes damaged or "tracked" by the alpha particles, and the amount of damage corresponds to the radon concentration over the measurement period.

Since this detector integrates the radon levels over time, it provides a more accurate representation of exposure, which is crucial in assessing health risks associated with radon. The long-term nature of Alpha Track Detectors makes them particularly useful for residential radon testing, allowing homeowners to obtain a realistic picture of radon levels in their environment.

In contrast, other devices like pulsed ion chambers and electret ion chambers are better suited for short-term measurements or do not offer the same level of temporal accuracy for average radon levels. Grab/sampling devices provide instantaneous readings and are not suitable for long-term assessment, thus highlighting the specific utility of Alpha Track Detectors in this context.