Why is NDT Personnel Competency Critical?

Non-destructive testing (NDT) aims to detect surface and internal discontinuities in a material or part without causing damage. However, in most of these methods, the test result depends as much—and often more—on the knowledge and skill of the inspector as on the equipment used. Two different operators using the same equipment might evaluate a critical crack in a weld seam differently.

Therefore, in NDT, personnel competence cannot be left to chance; it needs to be qualified and documented using objective criteria. TS EN ISO 9712 is an internationally accepted standard that precisely meets this need and impartially demonstrates that personnel are competent at a defined level in a specific method.

This content is for informational purposes only; evaluation for a specific inspection, part, or project should be performed by the relevant authorized engineer.

  • The outcome of the inspection largely depends on the competence of the personnel.
  • Competence must be based on objective and verifiable criteria.
  • TS EN ISO 9712 defines personnel competencies according to levels.

Scope of TS EN ISO 9712 Standard

TS EN ISO 9712 establishes internationally accepted principles for the qualification and certification of non-destructive testing personnel. The standard defines which methods, at what level, and in which industry/product sector personnel are considered competent; prerequisites such as training, experience, examination, and vision testing; the validity of the certificate; and recertification procedures.

The standard also includes the principle of providing individual written authorization from the employer: the document demonstrates the person's general competence, while permission to apply that competence to specific jobs in a particular workplace is complemented by written authorization from the employer.

The inclusion of the word 'certification' in the standard's name is inherent to the standard's subject matter; it does not mean that any organization can automatically issue certificates. Personnel certification under ISO 9712 is carried out by certification bodies accredited for this purpose.

  • Competency definitions based on method, level, and sector.
  • Education, experience, examination, and vision test are prerequisites.
  • Employer's responsibility for written authorization.

Three Competency Levels: Levels 1, 2, and 3

TS EN ISO 9712 defines NDT personnel in three levels according to increasing levels of responsibility. Each level covers the competencies of the previous level and adds new responsibilities.

This hierarchical structure between levels ensures that each stage of the inspection process—from implementation to interpretation, procedure development to personnel authorization—is carried out by appropriately competent individuals.

  • Level 1: Performs the examination according to written instructions and under supervision, adjusts the device, records the results, and reports them. Does not make the acceptance/rejection decision independently.
  • Level 2: Selects and applies appropriate techniques, prepares inspection instructions according to standards, evaluates and interprets results and reports; directs/supervises Level 1 personnel.
  • Level 3: Develops and approves NDT procedures, defines methods and techniques, contributes to the content of examinations, provides technical support for the training and authorization of Level 1 and 2 personnel, and assumes technical responsibility for the inspection unit.

Basic NDT Methods

Within the scope of TS EN ISO 9712, personnel are individually qualified and certified for each method; being certified in one method does not imply competence in others. The most commonly used surface and volumetric inspection methods in the manufacturing, welding, and pressure vessel sectors are summarized below.

The choice of method depends on the type of material, the nature of the discontinuity being sought (surface/subsurface/internal), and the relevant product standard. Selecting the correct method and technique is the responsibility of appropriately qualified personnel.

  • MT (Magnetic Particle): Detection of surface and near-surface discontinuities in ferromagnetic materials.
  • PT (Liquid Penetrant): Making surface-level discontinuities visible through capillary action.
  • RT (Radiographic): Imaging of internal discontinuities using X-rays or gamma rays.
  • UT (Ultrasonic): Measurement of internal discontinuities and thickness using high-frequency sound waves.
  • Eddy Current (EC): Electromagnetic detection of surface and near-surface defects in conductive materials.
  • VT (Visual Inspection): Direct or instrumental examination of surface condition, geometry, and visible defects.

Documentation Process

Certification according to TS EN ISO 9712 relies on the simultaneous fulfillment of multiple prerequisites. Passing the exam alone is not sufficient; the candidate must also document specific educational and industrial experience.

The process generally includes completing the defined training for the relevant method and level, acquiring the necessary work experience, successfully passing theoretical and practical exams, and undergoing a vision examination (near vision and color/grayscale discrimination).

The certificate is not perpetual; it has a specific validity period, during which regular renewal of vision examinations and uninterrupted activity are expected. At the end of this period, the certificate is renewed through recertification according to the conditions defined in the standard; re-examinations may be required at certain intervals. For exact durations and periods, the current text of the standard and the rules of the relevant certification body should be taken as a basis.

  • Training tailored to the method and level.
  • Documented industrial experience.
  • Theoretical and practical exam.
  • Vision examination (near vision and color/grayscale discrimination).
  • Recertification at the end of the validity period.

Application Sectors and Employer's Responsibility

TS EN ISO 9712 certification is carried out according to product and industry sectors. Each sector, such as welded fabrication, forging and casting products, pipes and tubes, pressure vessels, steel structures, railway and aerospace, has its own specific inspection requirements. The candidate's certificate includes the sector scope as well as the method and level of competence demonstrated.

The document demonstrates a person's general competence; however, written authorization from the employer is required for that person to actually conduct examinations at a specific workplace. The employer is responsible for verifying that the employee possesses a valid document appropriate to their role, keeping records of annual vision examinations, and providing the individual with specific written authorization.

This structure strengthens the traceability and accountability of the inspection process by separating documented competency from workplace-specific authorization.

  • The scope of the industry includes welding, pressure vessels, pipes/tubes, casting-forging, and steel structures.
  • Document = general competence; written authorization = workplace-specific permission.
  • The employer verifies the valid documentation and vision examination records.

Why is it important for exports?

In international markets, particularly in the export of welded fabrication, steel structures, and pressure equipment to Europe and other developed markets, end buyers and product standards often require inspections to be carried out by personnel certified according to TS EN ISO 9712. This has become more than a technical preference; it is a contractual and conformity requirement.

Inspections carried out by certified personnel increase the acceptability of inspection reports, reduce the risk of nonconformity during buyer audits and third-party inspections, and demonstrate that the product meets the regulatory/standard expectations of the target market in a traceable manner.

For Turkish manufacturers and exporters, working with NDT personnel certified under TS EN ISO 9712 is a fundamental element in proving product safety and remaining competitive in international supply chains.

  • End buyers often require ISO 9712 certified personnel.
  • It increases the acceptability and traceability of inspection reports.
  • It reduces the risk of non-conformities in buyer and third-party inspections.

Information Note

AES is NOT an NDT personnel certification body and DOES NOT issue personnel certificates/documents under ISO 9712. ISO 9712 certification is carried out by personnel certification bodies accredited by TÜRKAK under TS EN ISO/IEC 17024.

AES, as a TÜRKAK-accredited Type A inspection body, is accredited only in the field of '6.1 Electrical Installation'; NDT personnel certification is outside the scope of this accreditation.

The content on this page is for informational purposes only and is subject to the technical assessment of an authorized engineer. For specific inspection, standard interpretation, or certification needs, the relevant accredited organization and authorized engineer should be contacted.

  • AES does not issue personnel certificates/documents under ISO 9712.
  • AES is a TÜRKAK accredited Type A inspection body only in the field of '6.1 Electrical Installation'.
  • ISO 9712 certification is carried out by personnel certification bodies accredited according to TS EN ISO/IEC 17024.

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Frequently Asked Questions

What is TS EN ISO 9712?

Non-destructive testing (NDT) is an internationally recognized standard that defines the criteria for the qualification and certification of personnel at a specific method and level. It specifies the requirements for training, experience, examination, vision testing, and recertification.

What are the three levels of NDT and how do they differ?

Level 1 performs and reports on the inspection according to written instructions and under supervision; Level 2 selects the technique, prepares instructions, evaluates/interprets the results, and directs Level 1; Level 3 develops procedures, defines methods, and assumes technical responsibility for the inspection unit.

Which NDT methods does ISO 9712 cover?

The most common methods are MT (magnetic particle), PT (liquid penetrant), RT (radiographic), UT (ultrasonic), ET (edge current), and VT (visual inspection). Personnel are certified separately for each method.

How do I obtain the document and what is the process involved?

The process includes completing appropriate training at the specified method and level, documented work experience, passing theoretical and practical exams, and a vision examination. The certificate has a specific validity period, after which recertification is required. The current text of the standard should be used as the basis for the exact duration and periods.

Why are ISO 9712 certified personnel important in export?

Many end-buyers and product standards require inspections to be performed by ISO 9712 certified personnel as a contractual condition. This increases the acceptability of inspection reports and reduces the risk of nonconformities during buyer/third-party audits.

Does AES issue NDT personnel certificates under ISO 9712?

No. AES is not an NDT personnel certification body and does not issue personnel certificates/documents under ISO 9712. AES is only a TÜRKAK accredited Type A inspection body in the field of '6.1 Electrical Installation'. ISO 9712 certification is carried out by personnel certification bodies accredited according to TS EN ISO/IEC 17024. This content is for informational purposes only and is within the framework of authorized engineer technical evaluation.