ISO/ASTM 51707:2015

Overview - ISO/ASTM 51707:2015 (measurement uncertainty in dosimetry)

ISO/ASTM 51707:2015 is a technical guide for estimating measurement uncertainty of absorbed dose in radiation processing. It explains how to apply the JCGM “Guide to the Expression of Uncertainty in Measurement” (GUM) concepts to dosimetry systems, providing methods to identify, evaluate and combine uncertainty components into a coherent uncertainty budget and a formal statement of uncertainty. The standard is intended to support traceable dose measurement, quality assurance, and compliance with related dosimetry requirements.

Key topics and technical requirements

• GUM methodology: Use of the JCGM/GUM approach to evaluate Type A (statistical) and Type B (other) uncertainty components.
• Identification of components: Systematic listing of dosimetry uncertainty sources (instrument, calibration, environmental/influence quantities such as temperature, dose-rate, energy).
• Combination rules: Procedures for calculating combined standard measurement uncertainty and deriving expanded (overall) uncertainty using a coverage factor (k) - guidance notes that k is typically in the range of about 2–3.
• Probability distributions: Characterization of uncertainty components by appropriate distributions (normal, rectangular, etc.).
• Uncertainty budgets and statements: Worked examples showing how to build a budget, quantify contributors, and prepare a formal uncertainty statement for absorbed dose (Gy).
• Terminology & traceability: Definitions (measurand, traceability, repeatability, reproducibility) and emphasis on metrological traceability to accredited labs or national standards.
• Use cases for estimates: How uncertainty estimates support process control, calibration, performance characterization and conformity assessment.

Practical applications and typical users

Who uses ISO/ASTM 51707:2015:

• Dosimetry engineers and scientists developing dose measurement protocols.
• Radiation processing facilities (gamma, electron beam, X‑ray) performing dose mapping, product validation and routine process control.
• Calibration laboratories and accreditors seeking ISO/IEC 17025 traceability.
• Quality managers and regulatory bodies concerned with sterilization (e.g., ISO 11137) and product radiation treatment validation.
• Researchers and instrument manufacturers characterizing dosimeter performance.

Practical benefits:

• Produces transparent, reproducible uncertainty budgets for absorbed dose.
• Improves confidence in dose-based QA decisions and regulatory compliance.
• Facilitates comparisons between dosimetry systems and laboratories.

Related standards and references

Relevant companion documents cited in ISO/ASTM 51707:2015:

• ISO/ASTM 52628, 51261, 52701 (dosimetry practice and performance characterization)
• ISO/ASTM 51608, 51649, 51702 (facility-specific dosimetry practices)
• JCGM 100 (GUM) and JCGM 200 (VIM) - for uncertainty and terminology guidance
• ISO/IEC 17025 (laboratory competence) and ISO 11137 (sterilization requirements)

Keywords: ISO/ASTM 51707:2015, measurement uncertainty, dosimetry, absorbed dose, radiation processing, GUM, uncertainty budget, expanded uncertainty, traceability.