NDT in accordance with DIN EN ISO 9712: Who may prepare and approve testing instructions?

It is one of the most common questions in non-destructive testing (NDT): “As a certified Level 2 examiner at Company A, may I write a testing instruction and then use it to carry out testing at Company B?” This question often arises because companies would like to offer their employees’ NDT expertise as a service. At the same time, the role and function of a Level 3 examiner are not always clearly understood in practice.

Testing instructions prepared by Level 2 examiners

As a general principle, a qualified or certified Level 2 NDT examiner may prepare testing instructions. However, this only fulfils part of the requirements. Additional rules must be observed when a testing instruction is to be used in an external environment.

The four-eyes principle in practice

If a Level 2 examiner certified in accordance with DIN EN ISO 9712 writes a testing instruction and then wishes to use it to test at another company, the four-eyes principle applies. In practice, this means that a Level 3 examiner must approve the testing instruction from a technical perspective.

This approval may be given by different people:

• a Level 3 examiner from their own company (Company A)
• a Level 3 examiner – or, where applicable, a examiner with the corresponding responsibility – from Company B, where the testing is to take place
• a Level 3 examiner from an external testing service provider (Company C)

Only after this technical approval may the testing instruction be used in the testing process.

Authorisation as part of the testing order

In practice, it is also advisable to make the approved testing instruction part of the testing order. This means that the customer (Company B) should authorise the testing instruction for the specific order. This ensures that both technical responsibility and its use in the testing process are clearly defined.

W.S. Werkstoff Service – Expertise in NDT

In such cases, W.S. Werkstoff Service GmbH often acts as an external testing service provider. Our company can provide Level 3 personnel to support the technical approval of testing instructions in accordance with the requirements of the standard. Further information about our NDT services is available on our website:

• at the W.S. MaterialtestCenter: Non-destructive testing.
• specifically for the railway sector at the W.S. RailwayCenter: NDT competence centre.

If you would like to take the next step in your qualification, the W.S. TrainingCenter offers suitable continuing education opportunities. Further information is available at https://www.werkstoff-service.de/en/w-s-trainingcenter/book-courses-and-seminars/.