Which measurement method uses activated charcoal for sampling radon?

The method that utilizes activated charcoal for sampling radon is indeed associated with charcoal liquid scintillation. This technique employs activated charcoal to adsorb radon gas from the air, after which the radon is subsequently counted using scintillation detection methods. This approach is effective because the charcoal captures radon efficiently, and the subsequent measurement can provide valuable data on radon levels.

The other measurement methods mentioned do not use activated charcoal. Continuous working level monitors typically measure the decay products of radon rather than the radon gas itself. Electret ion chambers use electrets to detect alpha particles emitted from radon decay and do not involve charcoal in their sampling face. Continuous radon monitors utilize different technological mechanisms to measure radon levels, and again, do not rely on activated charcoal for sampling. Understanding the distinctions between these methods helps clarify why charcoal liquid scintillation is the correct answer for this particular question.