Which set of devices is used to directly measure shielding effectiveness by monitoring ambient room radiation?

• A. Geiger counters
• B. equipment survey devices
• C. environmental survey devices
• D. personal dosimeters

Answer: (C)

Directly assessing shielding effectiveness means measuring the actual ambient radiation present in the room. Environmental survey devices are designed for this purpose—they act as area monitors that can be placed at various locations to map the room’s ambient exposure rates. By tracking how the radiation level changes with different barriers in place, they provide a straightforward readout of whether the shielding keeps the dose in occupied areas within acceptable limits, which is exactly what you need to verify shielding adequacy.

Geiger counters can detect radiation and are handy for quick spot checks, but they aren’t ideal for accurate, room-wide ambient dose-rate measurements or long-term monitoring across multiple points. Equipment survey devices are focused more on the characteristics and performance of the imaging equipment itself, not the general ambient field in the room. Personal dosimeters measure an individual’s exposure, not the room’s radiation environment, so they don’t evaluate shielding effectiveness.

So, the best fit for directly measuring shielding effectiveness by monitoring ambient room radiation is environmental survey devices.