What is a key difference between OSLDs and TLDs in radiation dosimetry?

• A. OSLDs require heating to read, while TLDs provide immediate readouts.
• B. TLDs offer immediate readouts and reusability, while OSLDs are exposed and read later, usually one-time use per exposure.
• C. OSLDs provide immediate readouts and reusability, while TLDs are exposed and read later, usually one-time use per exposure.
• D. Both types are read immediately after exposure and are reusable.

Answer: (C)

Reading method and reuse distinguish OSLDs from TLDs. OSLDs store energy when exposed to radiation, and you read them by stimulating with light; this readout is quick and the dosimeter can be reset with light and reused for future exposures. TLDs, on the other hand, require heating to release the stored energy as light, so the readout is not immediate and, after reading, the device must be annealed to reset it for reuse. Because of that, TLDs are typically used once per exposure before reconditioning, while OSLDs can be read and reused multiple times. That’s why the correct option describes OSLDs as providing immediate readouts and reusability, and TLDs as read later with typically one-time use per exposure.