NDT Certification Systems
The need for competent personnel to perform NDT tasks is paramount in all industries. In order to determine competency, systems have been devised to ensure that NDT personnel have the proper training, have passed written and practical examinations, and have enough experience to properly perform NDT tasks using the applicable test method or technique. Personnel that have met all three of these requirements are said to be “qualified,” and once qualified they can be certified, which is defined in several different ways under the various NDT systems.
The following terms are used here for descriptive purposes only and should not be considered to be formal (or “official”) definitions:
Certification Standard: National or international documents describing the requirements for the qualification and certification of NDT personnel. (See the Codes and Standards web page.
Recommended Practice: A formal document that provides nationally or internationally recognized guidelines, and describes the qualification and certification process for NDT personnel. If mandated by governing codes, standards, specifications or contract documents, these guidelines become requirements for the specified project.
Certification System: The combination of the standard or recommended practice governing the certification requirements, the third-party certification program (if applicable) or the employer's written practice, and additional employer documents used in the administration of their certification program.
Certification Program: The documented employer’s or certification body’s procedures and processes based on a standard or recommended practice, which defines the requirements of that specific program.
NDT Certification Systems
There are multiple NDT certification systems worldwide, but they can generally be divided into two main types: “employer-based” and “central” certification systems.
Employer-based certification systems are systems in which the employers are responsible for the administration of the training and the qualification examinations of their own employees, as well as the documentation of the required training, examinations and experience in accordance with an employer-based standard or recommended practice. Most employer-based systems do allow the employer to accept training and examination services provided by outside agencies provided it is properly documented and the employer has determined that the content of those services meet their own company requirements as described in the employer's Written Practice.
Upon proof of qualification, the employer may issue a certificate, which can be a formal certificate or in letter format, and can authorize their personnel to perform NDT tasks. In all employer-based systems, the employer is responsible for authorizing their personnel to perform such work. Because employer-based certification is usually tailored to an employer's specific needs, the resulting certifications expire when an employee leaves the company that issued the certification.
Central certification systems are systems in which the qualification examinations are administered by an independent third-party certification body based on a central certification standard. To be eligible to sit for these examinations, prospective candidates must provide acceptable documentation of their training and experience to the certification body. Upon successful completion of the third-party examinations, the certification body will issue a certificate attesting to the fact that the named certificate holder has met the requirements and passed the examinations described in the third-party certification system. The employer can then choose to accept the third-party certificate(s) as proof of qualification. As with employer-based systems, the employer has the ultimate responsibility to certify (authorize) the certificate holder to perform NDT tasks.
Levels of Qualification
Most certification programs have three levels of NDT qualification: Level I, Level II and Level III. Because the requirements for the levels are very similar, the descriptions provided here are from the 2006 edition of the ASNT Recommended Practice No. SNT-TC-1A.
An NDT Level I individual should be qualified to properly perform specific calibrations, specific NDT and specific evaluations for acceptance or rejection determinations according to written instructions and to record results. The NDT Level I should receive the necessary instruction and supervision from a certified NDT Level II or III individual.
An NDT Level II individual should be qualified to set up and calibrate equipment and to interpret and evaluate results with respect to applicable codes, standards and specifications. The NDT Level II should be thoroughly familiar with the scope and limitations of the methods for which he is qualified and should exercise assigned responsibility for on-the-job training and guidance of trainee