NDT General (Basic): Principles, Personnel, and Documentation
What the exam expects
A Level III is tested less on trivia than on judgment: why a method is chosen, how a technique is validated, and how results are documented and defended. You must be fluent in the standard NDT methods (VT, PT, MT, ET, RT, UT, LT, AE), their energy forms, and their relative strengths and blind spots. Know the difference between a discontinuity and a defect, and between detection and rejection - a defect is only a discontinuity that exceeds an acceptance criterion.
Qualification and certification
Understand the certification ladder (Trainee, Level I, II, III) and what each may do: Level I performs calibrated, standardized tests under supervision; Level II sets up, calibrates, interprets, and reports; Level III selects methods, establishes techniques, interprets codes, and trains/certifies. Be able to distinguish a certification (by a certifying body or employer) from a qualification (demonstrated capability). Questions love to test who may approve a written procedure versus who may perform it.
Documentation and traceability
Procedures, technique sheets, calibration records, and reports must be traceable. A report without instrument identification, calibration status, and technique parameters is indefensible. Know the role of reference standards and how they differ from calibration standards.
Traps
- Confusing sensitivity with resolution; higher gain is not higher sensitivity.
- Assuming a more sensitive method is always better - it may raise false calls.
- Mixing up the roles of code, specification, and standard.
- Forgetting that acceptance criteria come from the code, not the inspector.
Worked rule of thumb
If a question asks who may establish a technique, the answer is Level III. If it asks who may perform a standardized inspection to a written procedure, the answer is Level II (or Level I under supervision). Use this pairing as a quick filter on personnel questions.