At present, there are numerous certification systems for nondestructive testing personnel in China, which can pose challenges for enterprises and institutions when conducting qualification assessments and arranging for the certification of their NDT personnel. The majority of certifications in China are based on two major standards—ISO 9712:2012 and TSG Z8001-2019. What are the key similarities and differences between the certification systems corresponding to these two standards?

I. Introduction to the Management System

(1) Applicability of the Certification Certificate
Standard ISO 9712:2012 specifies the training, qualification assessment, and certification of nondestructive testing personnel. To enhance mutual recognition of such certificates among different countries and organizations worldwide, the International Committee on Nondestructive Testing (ICNDT) has initiated the ICNDT MRA Agreement (Multilateral Recognition Agreement for NDT Personnel Certification). Certification bodies that meet the ICNDT’s stringent assessment criteria will have their certificates recognized by an increasing number of countries and regions. ISO 9712:2012 is the standard for the training, qualification assessment, and certification of nondestructive testing personnel engaged in radiographic testing, ultrasonic testing, magnetic particle testing, liquid penetrant testing, acoustic emission testing, eddy current testing, leak testing, infrared thermography, strain measurement, visual inspection, and other NDT methods, primarily in the mechanical, construction, and export-product sectors both domestically and internationally. It applies to the training, qualification assessment, and certification of NDT personnel in these industries.

Standard TSG Z8001-2019 is the assessment regulation for nondestructive testing personnel engaged in radiographic testing, ultrasonic testing, magnetic particle testing, liquid penetrant testing, acoustic emission testing, eddy current testing, and leakage flux testing in the special equipment industry in China, and it applies to the assessment of nondestructive testing personnel in this industry.

(2) Main Organizational Structures
Under the ISO 9712:2012 certification system, there are three principal organizational entities: the certification body, the authorized qualification assessment body, and the examination center.

The Nondestructive Testing Branch of the Chinese Society of Mechanical Engineering (hereinafter referred to as “the Society”) is the sole certification body in China that meets the requirements of ISO 17024:2012 and the only one authorized to conduct qualification assessment and certification for nondestructive testing personnel in accordance with ISO 9712:2012.

In accordance with the requirements of ISO 9712:2012, the organization that manages the certification process is referred to as the certification body. An authorized qualification assessment body is an independent entity, separate from the employer, that has been accredited by the certification body and is responsible for the preparation and administration of qualification assessment examinations. The examination center holds examination questions and test specimens approved by the certification body and meets the requirements for qualification assessment examinations in the relevant levels, methods, and categories.

TSG Z8001-2019 establishes two principal organizational bodies: the certification authority and the examination authority. The new assessment rules have removed the provisions previously contained in TSG Z8001-2013 regarding training institutions. Under TSG Z8001-2019, the issuing authority for Level I and Level II certifications in radiographic testing, ultrasonic testing, magnetic particle testing, and liquid penetrant testing is the provincial market supervision and administration department; for all other nondestructive testing methods and levels, the issuing authority is the State Administration for Market Regulation, which also holds the final authority to interpret these rules.

Individuals holding nondestructive testing qualification certificates issued by other organizations or industries may, upon meeting the required educational and practical experience criteria, apply for a corresponding-method, corresponding-level special equipment nondestructive testing qualification certificate, with exemption from the closed-book theoretical examination.

(3) Other Similar Characteristics
Under the current various nondestructive testing certification systems, NDT personnel are typically classified into three technical levels. ISO 9712:2012 refers to these as “Level 1, Level 2, and Level 3,” while TSG Z8001:2019 designates them as “Class I, Class II, and Class III.”

II. Personnel Certification Requirements

(1) Application Requirements
ISO 9712:2012 stipulates that certification candidates must meet requirements regarding visual acuity, training, and industrial experience. With respect to visual acuity, at a viewing distance of no less than 30 cm, regardless of whether corrective lenses are worn, the candidate must be able to read the Jaeger chart numeral “1,” Times New Roman N4.5 (with a font height of 1.6 mm), or equivalent-sized letters with one eye or both eyes; furthermore, the candidate’s color vision must be sufficient to distinguish the colors involved in the NDT methods specified by the employer. The certification system specifies minimum training hours and minimum industrial experience requirements for each level and method; where the relevant conditions are met, these requirements may be reduced, provided that the minimum training hours do not fall below 50% of the standard requirement and that there are no significant interruptions in the nondestructive testing work experience. Industrial experience must be documented and verified by the candidate’s employer and subsequently reviewed by the qualification assessment body.

TSG Z8001-2019 sets forth the requirements that candidates must meet with respect to visual acuity, educational qualifications, length of certification holding, and age. Candidates shall not be older than 60 years of age; for those applying for radiographic testing, magnetic particle testing, liquid penetrant testing, and leakage flux testing, uncorrected or corrected visual acuity in one or both eyes must reach at least 5.0 as specified in GB 11533-2011; for those applying for ultrasonic testing, acoustic emission testing, and eddy current testing, uncorrected or corrected visual acuity in one or both eyes must reach at least 4.8 as specified in GB 11533-2011; and candidates applying for magnetic particle testing and liquid penetrant testing must not be color-blind. With regard to training hours, TSG Z8001-2019 does not impose any specific requirements; however, it does stipulate the minimum length of time that a certificate must have been held before applying for a particular method and level. When applying for Level II or Level III qualification, the certificate held by the candidate must be within its validity period. The required length of certification holding for applying for certificates of the same method and level primarily depends on educational background: candidates with higher education and degrees in science and engineering are subject to relatively shorter requirements. Notably, candidates holding diplomas from non-engineering secondary vocational schools, vocational high schools, technical schools, or having completed junior or senior high school are ineligible to apply for Level III certification. For candidates with an associate degree or higher in science and engineering, when applying for assessment and certification under the four standard methods—ultrasonic testing, radiographic testing, liquid penetrant testing, and magnetic particle testing—they may directly apply for Level II certification under TSG Z8001-2019. However, when applying for Level 2 certification under ISO 9712:2012, candidates must still satisfy the corresponding requirements regarding industrial experience and training hours.

(2) Assessment Methods and Content
TSG Z8001-2019 stipulates that all examination subjects are graded on a 100-point scale, with a passing score of 70 for both the theoretical knowledge examination and the practical skills examination. ISO 9712:2012, on the other hand, requires candidates at Levels 1 and 2 to achieve a minimum score of 70 in each component of the examination—namely, the general section, the specialized section, and the practical skills section. In the practical skills examination, each test specimen and, where applicable, the NDT procedure card must each receive a minimum score of 70. For Level 3 candidates, the examination comprises three components in the foundational exam: materials science and manufacturing processes; the qualification assessment and certification system of the certifying body; and Level 2 general knowledge covering at least four methods, including one volumetric testing method. Each of these three components must also achieve a minimum score of 70. The principal examination components for Level 3 include Level 3-specific knowledge related to the applied testing method, the application of NDT methods in the relevant disciplines, and the NDT procedure specifications for those disciplines, with a minimum score of 70 required in each component. Both systems set the passing threshold for each examination subject at 70% of the total score; however, there are differences in the specific examination formats and content requirements.

ISO 9712:2012 stipulates that candidates must first undergo appropriate training, the syllabus for which is ISO/TR 25107:2006. The minimum number of training hours required for volumetric testing methods (such as UT and RT) is higher than that for surface testing methods (such as MT and PT). The minimum training hours for the four conventional testing methods are shown in the following table:

With regard to certification, the ISO 9712:2012 certification system stipulates that each nondestructive testing method encompasses more than one discipline. In China, based on this standard, the Society classifies products into four major categories: welding (W), forging (F), casting (C), and piping (T). Candidates for Levels 1 and 2 are required to pass both a general examination and a discipline-specific examination. The general examination is administered as a closed-book test, while the discipline-specific examination consists of both practical assessment and a written test, with assessments conducted separately for each discipline; the written component is open-book. For the practical examination, the standard also specifies the corresponding evaluation criteria and their respective weights. Notably, all closed-book examinations consist exclusively of multiple-choice questions, and there are specific requirements regarding the number of questions.

The examination for nondestructive testing personnel of special equipment comprises a theoretical examination (closed-book and open-book) and a practical skills examination. The theoretical knowledge examination utilizes a nationally standardized question bank, with Appendix C of TSG Z8001-2019 serving as the examination syllabus. During the examination, no distinction is made among different categories, and no specific requirements are imposed on the types or number of questions.

ISO 9712:2012 stipulates that personnel undergoing initial certification who fail the examination in a given subject shall be entitled to two retake opportunities for that subject within a two-year period. According to TSG Z8001:2019, personnel undergoing initial certification who do not pass the assessment shall be entitled to one retake opportunity within a two-year period.

III. Extension and Re-certification Requirements

According to the Society’s current regulations, for Level 1 and Level 2 certified personnel under ISO 9712:2012, re-certification—similar to the requirements of TSG Z8001-2019—requires only completion of the practical examination in the relevant discipline. For Level 3 personnel, re-certification may be achieved either by passing the examination or through the points-based system. The specific requirements for the composition of the points system used for Level 3 re-certification are detailed in Appendix C.

IV. Personnel and Records Management

Under the ISO 9712:2012 certification system, the Society is responsible for reviewing application materials; upon fulfillment of all certification requirements, the certification body will issue the certificate. Both applicants and certificate holders are required to adhere to the Code of Ethical Conduct. Certificate holders must undergo an annual vision examination as prescribed and report the results to their employer.

ISO 9712:2012 adopts an employer-approval system, emphasizing the employer’s responsibilities and the importance of their role within the certification framework. The certification serves as evidence of the general competence of NDT personnel, while tasks such as operational authorization remain the employer’s responsibility.

In terms of records management, the ISO 9712:2012 certification system requires certification bodies or authorized qualification assessment bodies to be responsible for maintaining records. The records that these bodies must maintain include: a database and up-to-date list of all certified personnel, categorized by level, NDT method, and discipline; the individual file for each candidate who has applied for certification but has not yet been certified; and the individual files for each certified person as well as for those whose certification has lapsed. Individual files shall be stored in an appropriate, secure, and confidential environment for at least one full certification validity period following the expiration of the certificate.

Under the TSG Z8001-2019 certification system, the examination authority is responsible for reviewing application materials; candidates who meet the requirements may take the examination. While TSG Z8001-2019 does not include a requirement for a code of ethical conduct, it does stipulate that nondestructive testing personnel must comply with relevant professional practice requirements and must also adhere to the pertinent provisions of the Special Equipment Safety Law of the People’s Republic of China and the Regulations on the Supervision and Administration of Special Equipment Safety. In the management of nondestructive testing personnel for special equipment, examination authorities are required to archive examination papers, examination room records, and other related documents—whether in electronic or paper form—for a minimum period of eight years. Any instances of examination cheating or violations of laws and regulations in the course of professional practice shall be recorded by the issuing authority in the individual’s nondestructive testing personnel file.

Conclusion

China currently has numerous nondestructive testing personnel certification systems, which often do not recognize each other, forcing inspectors to frequently travel back and forth to obtain or renew their certifications. ISO 9712:2012 and TSG Z8001-2019 are the two major training and certification frameworks in China today, with broad application. It is hoped that by comparing the key similarities and differences between these two standards, this analysis will provide some guidance for enterprises and institutions in selecting an appropriate training system.