The personnel monitoring device that can typically be worn for up to three months is?

The personnel monitoring device that can typically be worn for up to three months is the thermoluminescent dosimeter (TLD). TLDs are particularly effective for measuring ionizing radiation exposure over extended periods. They contain materials that absorb and store energy from radiation exposure, which can later be released as light when heated, allowing for precise measurement of the radiation dose received.

One of the key advantages of TLDs is their ability to provide long-term monitoring without the need for frequent replacement. This makes them especially useful in environments where personnel may be exposed to radiation over time, as they can continuously record exposure levels throughout their usage period, which usually spans several months.

In contrast, devices like film badges and pocket dosimeters have limitations in terms of wear duration and the types of radiation they can effectively measure. Film badges are usually replaced monthly due to their sensitivity and the nature of film deterioration, while pocket dosimeters provide real-time readings but are typically used for short-term monitoring and require immediate assessment of exposure. Geiger counters, on the other hand, are instruments used to detect and measure ionizing radiation but are not worn as personal monitoring devices. Instead, they are handheld devices used for surveying radiation levels in an environment.