Passive dosimetry is defined as

• A. A method of giving direct readings automatically
• B. A method of measuring radiation exposure without providing direct readings and without active functionality
• C. A system for real-time dose measurement
• D. A method that requires an electronic reader

Answer: (B)

Passive dosimetry uses dosemeter devices that record radiation exposure without giving any readout during use and without needing active electronic operation. These devices accumulate dose over a period and must be processed later, typically in a lab, to obtain the reading. That’s why this description fits best: it measures exposure but does not provide direct readings on the spot and does not rely on active functionality during use. Examples include film badges, thermoluminescent dosimeters (TLDs), and optically stimulated luminescence (OSL) dosimeters.

The other statements describe features of real-time or actively read dosimeters, or place emphasis on requiring an electronic reader during use, which is not what defines passive dosimetry.