Which personnel radiation monitoring device provides an accuracy of about plus/minus 25%?

The film badge is a personnel radiation monitoring device known for its widespread use due to its ease of use and effectiveness in providing a permanent record of radiation exposure. It functions by using photographic film that is sensitive to ionizing radiation. When exposed, the film darkens in proportion to the radiation dose received, which can then be measured after development.

The accuracy of the film badge is typically about plus/minus 25%, which means it can provide a reasonably good assessment of an individual's radiation exposure, but it is not the most precise option available. This level of accuracy is suitable for many monitoring scenarios in a medical or occupational health context, where tracking accumulated exposure over time is essential.

Other monitoring devices, such as TLDs (Thermoluminescent Dosimeters) and pocket dosimeters, offer higher precision in measuring radiation doses and typically have better accuracy ratings. An audible warning device is a safety tool used to alert personnel to high radiation levels but does not measure exposure. Hence, the film badge's characteristic of providing an accuracy of about plus/minus 25% makes it a relevant answer to this question.