IEC 61674:2024

Overview

IEC 61674:2024 - Medical electrical equipment - Dosimeters with ionization chambers and/or semiconductor detectors as used in X‑ray diagnostic imaging - is the third edition of the international standard that specifies performance and relevant constructional requirements for diagnostic dosimeters. It applies to dosimeters using vented ionization chambers and/or semiconductor detectors for measurement of air kerma, air kerma length product and air kerma rate in photon radiation fields used in radiography, radioscopy and computed tomography (CT) with X‑ray generating potentials from 20 kV to 150 kV.

Key topics and technical requirements

• Scope of measurement: air kerma, air kerma length product and air kerma rate for diagnostic X‑ray imaging (20–150 kV).
• Detector types covered: vented ionization chambers and semiconductor detectors (single and multiple detector assemblies, including CT detectors).
• Performance characteristics: requirements and limits for linearity, repeatability, resolution of reading, stabilization time and stability (short‑ and long‑term).
• Influence quantities: tests and limits for energy dependence, dose rate dependence, angle of incidence, air pressure, temperature and humidity, field size and spatial uniformity (especially for CT).
• Electromagnetic compatibility (EMC): ESD, radiated fields, conducted disturbances and voltage variations testing relevant to medical environments.
• Uncertainty and testing: guidance for estimating combined standard uncertainty of dosimeter performance (Annex A) and standard test conditions.
• Marking and documentation: detector and measuring assembly marking and accompanying documentation requirements.

Significant technical changes in the 2024 edition vs. 2012:

• Manufacturer‑specified reference radiation quality for mammography and minimum rated range for mammography energy‑dependence tests.
• Removal of the compliance test for analogue displays.
• Removal of separate tests for range reset and leakage/recombination losses (covered by linearity tests); changes to combined uncertainty estimation.
• Updated compliance tests for mains rechargeable and battery‑operated dosimeters.

Applications and practical use

IEC 61674:2024 is used to ensure dosimeters deliver accurate and traceable measurements in clinical X‑ray environments. Typical applications:

• Acceptance testing and performance verification of diagnostic dosimeters in hospitals and imaging centers.
• Product development, design verification and type testing by dosimeter manufacturers.
• Calibration and conformity testing by metrology and calibration laboratories.
• Regulatory compliance, procurement specifications and quality assurance programs used by medical physicists, radiology quality managers and health authorities.

Who should use this standard

• Dosimeter and detector manufacturers
• Medical physicists and clinical engineering teams
• Calibration laboratories and test houses
• Regulatory bodies and accreditation organizations
• Procurement specialists specifying diagnostic dosimeters

Related standards

• IEC 60601‑1 (terms and definitions referenced)
• Other IEC/ISO guidance on medical electrical equipment, radiological protection and calibration procedures

Keywords: IEC 61674:2024, diagnostic dosimeters, ionization chamber, semiconductor detector, air kerma, CT dosimeter, energy dependence, dosimeter performance, medical electrical equipment.