EN ISO 32679:2025 PDF

Overview

EN ISO 32679:2025 (identical to ISO 32679:2024) is a CEN/ISO standard for non‑destructive testing (NDT) by radiographic methods to determine the physical size of industrial gamma radiography sources. It defines a radiography procedure using X‑rays to measure source sizes ≥ 0.5 mm for radionuclides Ir‑192, Yb‑169, Se‑75 and Co‑60. The measured source size (d) is used to assess image quality and to validate or monitor manufacturing and installation of source inserts. Measurement accuracy is ±10 % (typically not better than ±0.1 mm). The method can be validated for other radionuclides.

Key topics and technical requirements

• Test geometry and alignment
  • Place X‑ray tube, gamma source and detector on a common axis.
  • Gamma‑source-to‑detector distance b should be 10–20 % of the total X‑ray‑source-to‑detector distance (a + b).
  • Geometrical magnification factor ν = (a + b) / a; measured projection d′ is corrected by 1/ν to obtain d.
  • Minimum focus‑detector distance of 700 mm for focal spots