Which statement correctly differentiates a passive dosimeter from an active dosimeter?

• A. Active dosimeters provide integrated dose read later; passive dosimeters provide real-time dose information.
• B. Passive dosimeters require power to operate.
• C. Passive dosimeters provide integrated dose when read later; active dosimeters give real-time dose information.
• D. Both provide real-time dose information.

Answer: (C)

The essential distinction is that passive dosimeters accumulate dose without a power source and are read after the exposure period, giving you an integrated dose once you process them. They don’t display or update dose information in real time during exposure. Active dosimeters, by contrast, have electronics and power and continuously monitor the radiation field, providing real-time dose information (and often alarms if dose rate or exposure exceeds limits). That real-time feedback is the hallmark of active dosimetry.

So the statement that passive dosimeters provide an integrated dose when read later, while active dosimeters give real-time dose information, best captures the difference.