Final answer:
Personal dosimeters, specifically film badges, could be most biased by changes in radon levels during the last 12 hours of deployment since they are less sensitive to quick fluctuations. Geiger counters and scintillators are more sensitive and better at registering emissions consistently.
Step-by-step explanation:
The student's question pertains to which measurement devices can have their measurement results biased the most from changes in radon levels during the last 12 hours of deployment. The most susceptible devices to radon level fluctuations among Geiger counters, scintillators, and dosimeters are likely to be the personal dosimeters, specifically the film badge type. Because the film in such dosimeters reacts to radiation exposure by darkening, a rapid change in radon levels can significantly alter the measurement results as these devices are less sensitive to low levels of radiation and may not accurately reflect short-term fluctuations.
Geiger counters and scintillators, on the other hand, are more sensitive and can register the number of emissions in a given time, making them potentially less prone to bias from sudden changes in radon concentration at the end of the deployment period. However, factors such as the sensitivity of the device, calibration, and type of radiation detected can influence the degree to which measurements are affected by changing radon levels.