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VT Visual Testing

Visual testing is an important non-destructive testing method (NDT), which usually preceds any further examinations. The EN 1090 regulation series requires a visual testing for all welded joints.

Often, the quality of a welded joint is agreed in accordance with the regulations of ISO 5817. The comparison of different testing methods, such as ultrasonic testing, X-ray testing, magnetic or penetration testing with visual testing, shows that about 60% of the criteria specified in ISO 5817 can be checked visually. Thus, the visual testing in such a comparison is to be regarded as the strongest method.

Qualification levels

 ISO 9712 differentiates between three qualification levels with different areas of responsibility. After authorization by the employer

  • Level 1 personnel can perform the test procedure and record the test results
  • Level 2 personnel can undertake Level 1 activities and evaluate the test results in accordance with standards and regulations
  • Level 3 personnel can undertake Level 2 activities and select the applicable test procedure and process descriptions on which the Level 2 staff can work. Level 3 personnel may take full responsibility for a test facility.

Course contents

The visual testing covers a wide range of different topics, such as:

Optical principles, lighting and viewing conditions, aids such as loupes, mirrors and endoscopes, discontinuities in different welding processes, cuts, fracture surfaces, evaluation according to regulations such as ISO 5817, signs of corrosion. One focus of the course is the standard-compliant logging of the test results and their legal aspects.


As an entry requirement for the course, the degree in a metalworking profession is recommended. If you have a degree as an engineer, technician or industrial foreman (technical area), you have the opportunity to take a shortened, 3-day course. Prerequisite for the test is the confirmation of the required visual capacity:

  • The close vision ability must be sufficient to read the Jaeger Number 1 letters or Times New Roman 4.5 or equivalent marks at a distance of not less than 30 cm with at least one eye, with or without visual aid
  • the color vision must be sufficient so that in the particular NDT process the contrast between colors or shades of gray can be recognized and distinguished, as determined by the employer

Furthermore, the employer must confirm an industrial previous experience of at least 10 days. If this previous experience is not available, then this can be acquired by a pre-practical internship in our house.
Certification for level 2 requires at least 4 months' prior industrial experience certified by the employer.


The qualification test is carried out by the personnel certification body of TÜV NORD. Usually the participant submits a certification application following his examination so that he receives a corresponding certificate. The certificates of TÜV NORD are DAKKS accredited and cover the industrial sector of welded joints when attending a VT 1/2 (w) course or, in the case of a multisectoral course, the industrial sectors "Castings (c)", "Forgings (f)", "welded products (w)","pipes and tubes (t)" and "rolled products (wp)".

Renewal and recertification

After a period of validity of the certificate vor 5 years, a renewal must be requested from the personnel certification body of TÜV NORD. In doing so, the employer must confirm that there has been no significant interruption in the candidate's continued work in the field of visual testing. The renewal is not connected with an exam.
The recertification in Level 2, which is due after another 5 years, is linked to a practical exam, the recertification exam. In the recertification exam, selected test pieces must be tested, the test results recorded and a test instruction has to be created. Usually, the candidate will pre-enroll in a recertification course in order to become familiar with the possibly revised regulations and the preparation of the test instructions.


Company courses

For groups of five or more participants, we are also happy to offer you our training courses in your company. In such in-house trainings, we can target your products and special requirements. We take care of test pieces and test equipment. Please organize a room for the theoretical lessons and maybe a separate room for the practical exercises.

We are happy to prepare an offer for your tailored further training.

Contact person

SLV München