Editing Nondestructive testing (section)

===Levels of certification===

Most NDT personnel certification schemes listed above specify three "levels" of qualification and/or certification, usually designated as ''Level 1'', ''Level 2'' and ''Level 3'' (although some codes specify Roman numerals, like ''Level II''). The roles and responsibilities of personnel in each level are generally as follows (there are slight differences or variations between different codes and standards):<ref name="ISO9712"/><ref name="EN4179"/>

* '''Level 1''' are [[technician]]s qualified to perform only specific [[calibration]]s and tests under close supervision and direction by higher level personnel. They can only report test results. Normally they work following specific work instructions for testing procedures and rejection criteria.
* '''Level 2''' are [[engineers]] or experienced technicians who are able to set up and calibrate testing equipment, conduct the inspection according to codes and standards (instead of following work instructions) and compile work instructions for Level 1 technicians. They are also authorized to report, interpret, evaluate and document testing results. They can also supervise and train Level 1 technicians. In addition to testing methods, they must be familiar with applicable codes and standards and have some knowledge of the manufacture and service of tested products.
* '''Level 3''' are usually specialized engineers or very experienced technicians. They can establish NDT techniques and procedures and interpret codes and standards. They also direct NDT laboratories and have central role in personnel certification. They are expected to have wider knowledge covering materials, fabrication and product technology.