Overview
EN ISO 20785-2:2020 - Dosimetry for exposures to cosmic radiation in civilian aircraft - Part 2: Characterization of instrument response (ISO 20785-2:2020) specifies minimum methods and procedures for characterizing how instruments respond when used to determine ambient dose equivalent (H(10))* in aircraft radiation fields. Published by CEN/ISO, this standard updates prior editions and supports traceable measurements for validation of calculated dose estimates for aircrew and passengers.
Key topics and requirements
- Scope and purpose: Establishes minimum requirements for instrument characterization used for cosmic radiation dosimetry at flight altitudes.
- Calibration fields and procedures: Defines recommended reference radiation fields, calibration setups and considerations for scattered and secondary radiation.
- Instrument characterization: Procedures to determine dosimetric characteristics, response functions and behavior under both reference and non‑reference conditions.
- Atmospheric radiation field: Discussion of the complex cosmic-ray field at altitude, including particle types and energy ranges relevant for measurements.
- Use of numerical simulations: Guidance on applying Monte Carlo or other simulations to evaluate instrument response where direct calibration is limited.
- Software requirements: Minimum expectations for instrument-related software development, testing and spreadsheet data analysis.
- Uncertainty and performance: Requirements for uncertainty estimation and remarks on performance tests to quantify measurement reliability.
- Informative annexes: Representative particle fluence energy distributions (solar min/max and cut-off rigidity), recommended calibration fields, comparison measurements and charged-particle irradiation facilities.
Practical applications and users
This standard is intended for organizations and professionals involved in aviation radiation protection, including:
- Calibration laboratories performing traceable calibrations of airborne dosimeters and survey instruments.
- Dosimetry instrument manufacturers designing and validating detectors and software for aircraft use.
- Airlines and aviation safety authorities implementing crew dose assessment and regulatory compliance (e.g., EU Basic Safety Standards).
- Radiation protection specialists and researchers validating modelled effective dose estimates by comparison with measured ambient dose equivalent.
- Regulatory bodies setting protocols for occupational exposure monitoring for aircrew (notably when annual doses may exceed 1 mSv).
Related standards
- Part of the ISO 20785 series on dosimetry for exposures to cosmic radiation in civilian aircraft; users should consult other parts of the series for complementary guidance (e.g., measurement methods, calibration practice and route dose assessment).
Keywords: ISO 20785-2:2020, cosmic radiation, dosimetry, ambient dose equivalent, H*(10), aircraft dosimetry, instrument characterization, calibration, aviation radiation measurements, uncertainty.