What is used to determine an individual’s radiation dose in the field?

An external dosimeter is a device specifically designed to measure an individual's exposure to radiation while performing work in areas where radiation may be present. These devices are worn on the body and provide a continuous measurement of dose accumulation, allowing for real-time monitoring of exposure levels.

External dosimeters are particularly useful in field situations where it is essential to track radiation exposure to ensure safety regulations and limits are adhered to. They typically measure ionizing radiation such as gamma rays and x-rays, providing immediate feedback to the user about their environmental exposure.

This method of dose measurement is crucial for maintaining safety in radiological environments, as it allows workers to be aware of their exposure levels and take necessary actions if they approach established dose limits. Other methods listed, such as bioassay samples or whole body counters, serve different purposes and are typically used in laboratory settings or for analyzing internal contamination rather than providing real-time dose monitoring in the field.