The outside area dosimeters used in AWST consist of a 4-element detector card for measuring the environmental dose equivalent H*(10) caused by X-ray, gamma and neutron radiation. Depending on the location, detectors with 6LiF (Mg, Ti) or 7LiF (Mg, Ti) are used.
When ionizing radiation hits the detectors, energy is stored in the detector crystal. By heating, part of this energy is released again in the form of light. The light intensity is a measure of the absorbed radiation.