1 level is simple. 1 theory: the general questions given by the examination institutions are given two exercises on it.

Two-level grading, merging and practical operation

Unpacking contents: pressure vessels, pressure pipes, boilers and related standards are mainly 4730.

Closed book content: basic knowledge of welding, metal materials and specific examination subjects

Textbooks such as X-ray testing, ultrasonic testing, magnetic particle testing, penetrant testing and nondestructive testing are universal. These four books depend on which subject you choose.

Practice is generally better, that is, two ways of radiographic testing: filming and film evaluation.