With the EC test, the amount of voltage reduction is directly related to which two factors?

The correct choice highlights that the voltage reduction in an Electret Ion Chamber (EC test) is directly influenced by the average radon concentration and the duration of the exposure period.

In an EC test, radon gas interacts with the electret, leading to a reduction in voltage that is measurable. The concentration of radon present in the air directly affects how many alpha particles are emitted as radon decays; a higher concentration results in a greater number of interactions, which translates to a more significant reduction in voltage.

Moreover, the duration of exposure is crucial because the longer the electret is exposed to radon, the more alpha particles it detects. This prolonged exposure provides a cumulative effect, intensifying the voltage reduction over time. Essentially, both factors work together: a higher concentration and a longer exposure period create a more pronounced voltage reduction, which is read and interpreted to ascertain the level of radon present.

In contrast, other answers present factors that do not have a direct relationship to the voltage reduction. For instance, while temperature and humidity can influence the performance of radon detectors in general, they do not correlate with the voltage reduction caused specifically by radon concentration and exposure duration. Thus, these aspects do not play a direct, measurable