What is the unit for measuring air kerma?

Air kerma is measured in Grays (Gy), which quantifies the energy deposited in air by ionizing radiation. Specifically, one Gray is defined as the absorption of one joule of radiation energy by one kilogram of matter, which in this context refers to the air. Air kerma is particularly important in radiology and radiation therapy as it helps in assessing the radiation dose delivered to a specific volume of air, which is crucial for understanding and controlling exposure to patients and staff.

The other units mentioned serve different purposes: Sieverts measure the biological effect of radiation and are related to the dose equivalent. Röntgens quantify exposure in air but do not account for energy absorption, making them less useful for certain applications where energy transfer is critical. Coulomb per kilogram is a unit of charge density used in the context of ionization in air but is not a direct measurement of energy deposition like the Gray. Thus, Gray is the appropriate unit utilized to express air kerma.