Overview
ISO/TS 22809:2007 - Non-destructive testing - Discontinuities in specimens for use in qualification examinations - defines the types, sizes and presentation of discontinuities in test specimens used for NDT qualification and certification. As an ISO Technical Specification, it guides examination centres in preparing realistic, sector-specific specimens for practical NDT examinations and in documenting discontinuities for candidate assessment.
Key topics and requirements
- Scope and purpose: Specifies discontinuity types to be exhibited in specimens for qualification examinations; excludes methods such as acoustic emission, infrared thermography, strain and leak testing where discontinuity type need not be defined.
- Specimen sectors: Details specimen configurations and representative discontinuity types for:
- Castings (c)
- Welded test specimens (w)
- Wrought products (wp)
- Forgings (f)
- Tubes and pipes (t)
- Minimum specimen numbers: Examination centres must hold a calculated minimum number of specimens based on the number of specimens per practical exam and the maximum simultaneous candidates.
- Minimum discontinuity sizes (method-specific):
- Radiographic testing (RT): planar ≥ 5 mm; pores ≥ 2 mm; clusters ≥ 5 mm; inclusions ≥ 3 mm. (RT specimens may omit physical discontinuities for interpretation exams.)
- Ultrasonic testing (UT): planar length ≥ 5 mm; through‑wall extent ≥ 2 mm or 20% of wall thickness (whichever is less); calibration reference = 3 mm side‑drill; volumetric ≥ 5 mm.
- Magnetic particle / Liquid penetrant (MT / PT): linear ≥ 3 mm; rounded or clusters ≥ 5 mm.
- Eddy current (ET): linear ≥ 2 mm.
- Visual testing (VT): surface discontinuities ≥ 1 mm (direct and remote aided VT).
- Surface conditions: Test areas must be free from dirt, oil, loose corrosion products, roughness or coatings that interfere with inspection.
- Number of discontinuities: Recommended minimum reportable discontinuities presented to a candidate: four for product sectors, six for industry sectors.
- Radiographic interpretation: Radiographs used in practical exams must be of suitable quality, contain at least one mandatory reportable discontinuity, and include datum/reference points.
- Specimen master report: All discontinuities relevant to evaluation must be recorded on a specimen master report in line with ISO 9712 requirements.
Applications and who uses this standard
- NDT examination and certification bodies preparing practical qualification tests.
- NDT trainers and centres designing realistic specimens for candidate assessment.
- Quality, inspection and welding personnel in industries such as oil & gas, power generation, aerospace, manufacturing and foundry work, where certified NDT personnel are required.
- Employers and regulatory authorities setting competency demonstration criteria for inspection staff.
Related standards
- ISO 9712:2005 - Qualification and certification of NDT personnel (referenced for terms and specimen master report format)
- ISO 4063 - Welding process nomenclature
- ISO 6520-1 - Classification of geometric imperfections (fusion welding)
Practical takeaway: ISO/TS 22809:2007 helps ensure that NDT qualification specimens are realistic, method-appropriate and consistently documented, improving the reliability of personnel certification and on‑site inspection competence.