What do frisker alarms indicate?

Frisker alarms are employed in radiation safety practices to detect the presence of contamination. These alarms are specifically designed to alert personnel to areas or items that may be contaminated with radioactive materials. When using a frisker, if radioactive contamination is detected, an alarm will sound, prompting the worker to take appropriate safety measures, such as decontaminating the area or item or using personal protective equipment. This function is crucial to maintaining safety in environments where radiation exposure is a concern, helping prevent the spread of contamination and ensuring the health and safety of workers and the public.

The other options do not relate to the primary function of a frisker. High levels of ambient temperature and low humidity levels pertain to environmental conditions rather than radiation detection. Anomalies in thickness measurements refer to physical measurements unrelated to contamination monitoring. Thus, the primary and correct role of a frisker is to indicate the presence of contamination, making option B the right choice.