dosmätning

Dosmätning, or dosimetry, is the measurement and assessment of ionizing radiation doses absorbed by matter or living tissue. It encompasses methods for characterizing radiation fields, estimating doses to patients, monitoring occupational exposure, and supporting radiation protection decisions. The field includes physical dosimetry, which deals with energy deposition, and medical dosimetry, which focuses on patient dose planning and evaluation in diagnostic radiology, nuclear medicine, and radiotherapy.

Types of dosimetry include personal dosimetry for workers, environmental dosimetry to measure ambient radiation levels, and medical dosimetry to estimate doses received by patients in clinical procedures. Dosimetry methods are broadly categorized as passive and active. Passive dosimeters, such as film badges, thermoluminescent dosimeters (TLD), optically stimulated luminescence (OSL) dosimeters, and glass dosimeters, store information for later readout. Active or electronic dosimeters provide real-time dose data, often using ionization chambers or semiconductor detectors. Ionization chambers are commonly used as reference instruments in calibration and calibration laboratories.

Dose quantities and units include absorbed dose (gray, Gy), equivalent dose and effective dose (sievert, Sv), which account for radiation type and tissue sensitivity. Exposure historically used units like roentgen; modern practice relies on SI units such as Gy and Sv. Practical dosimetry guides clinical dose planning, radiation protection, and regulatory compliance.

Applications span diagnostic radiology and computed tomography, radiotherapy treatment planning, nuclear medicine, occupational safety, and environmental monitoring. Standards and regulations are set by national authorities and international bodies (e.g., ICRP, IAEA, ISO), with dosimetry audits and quality assurance ensuring accuracy, traceability, and safety. Ongoing advances include real-time wearable dosimeters and improved materials for more accurate, low-uncertainty measurements.