Which devices have the disadvantage of no permanent record of radiation exposure?

• A. 2 and 3
• B. 1 and 2
• C. 1 and 3
• D. 1, 2, and 3

Answer: (C)

Permanent records come from dosimeters that store and archive exposure data, so you can look back at a history of dose over time. Some devices, however, only show the current exposure when you check them and don’t automatically keep a lasting log unless you manually record the value. Those are the direct-reading, no-permanent-record types.

In this question, the two devices described as giving an immediate readout without an ongoing log fit into that category. The others record exposure data in a durable form (such as a film or a memory-equipped dosimeter that stores past doses), providing a permanent record. Therefore, the combination of the two no-permanent-record devices is the best choice.