Overview
ISO 15708-1:2017 - "Non-destructive testing - Radiation methods for computed tomography - Part 1: Terminology" defines the standardized vocabulary for computed tomography (CT) within non-destructive testing (NDT). The document collects CT-specific and more general imaging and radiography terms, clarifies meanings (with some discussion points) and frames terminology to the specific context of CT. It is a reference for consistent language in documentation, testing procedures, specifications and training.
Key Topics
The standard focuses on precise definitions and concepts used in CT and radiographic imaging, including:
- Basic interaction mechanisms: absorption (photoelectric effect) and Compton scattering as photon–matter interactions.
- Beam characteristics: beam hardening (spectral change) and related effects such as the cupping effect.
- Acquisition geometries: cone‑beam, fan‑beam, and parallel‑beam CT modes.
- Data and image elements: projection, sinogram, reconstruction, image (tomogram), slice, volume, pixel and voxel.
- Quantitative measures: gray value, linear attenuation coefficient, density resolution, attenuation of X‑rays.
- Image quality and limits: artefact, partial volume effect, slice thickness, region of interest (ROI), local CT (ROI CT).
- System and test objects: CT system (tomograph) and calibration phantom (standard).
The standard does not set performance thresholds; its requirement is to provide authoritative terms and definitions to ensure clarity in NDT CT communications and documents.
Applications
ISO 15708-1:2017 is used to:
- Standardize terminology in CT test procedures, reports and specifications for industrial NDT.
- Improve communication between CT system manufacturers, inspection service providers and end users.
- Support training materials and certification programs for CT operators and inspectors.
- Aid researchers, metrology labs and regulators in unambiguous reporting of CT results and methods.
- Provide a reference for writing and harmonizing other standards or technical documents involving CT imaging.
Who should use this standard
- NDT engineers and radiographers working with industrial CT
- CT system designers and manufacturers
- Quality assurance and inspection managers
- Standards developers, regulators and testing laboratories
- Technical writers and trainers producing CT procedures and documentation
Related standards and resources
- The ISO 15708 series (other parts cover methods and requirements for CT) - see ISO for the list of parts.
- ISO Online Browsing Platform and IEC Electropedia for standardized terminologies and cross-references.
Keywords: ISO 15708-1:2017, computed tomography terminology, NDT CT, radiation methods, CT vocabulary, CT imaging terms, beam hardening, attenuation coefficient, voxel, sinogram.
Open preview (PDF)Non-destructive testing — Radiation methods for computed tomography — Part 1: Terminology
