How are activated charcoal detectors primarily designed to function?

Activated charcoal detectors are specifically designed to function by capturing radon gas present in the environment. The charcoal material has a high surface area and is effective at adsorbing radon gas molecules that pass through the detector. When radon gas is captured on the activated charcoal, it can then be measured later, typically by using scintillation counting or other analytical methods, which provide an indication of the concentration of radon in the air.

Other methods listed, such as releasing chemicals, measuring radiation levels, or analyzing temperature changes, do not accurately describe the primary operational mechanism of activated charcoal detectors. These other concepts may pertain to different types of detection technologies but do not apply to the functioning of activated charcoal detectors in the context of radon measurement.