SNT-TC-1A is a recommended practice, not a specification. It gives an employer a starting point for a written practice; the written practice, once issued, is the document that actually governs qualification. Every hour figure below is a recommendation that an employer may raise, and may only lower where the written practice states the alternative and the Level III accepts it. Contract specifications (ASME, API, client specs) frequently override the recommendation upwards.

Two different quantities are counted. Organised training is formal classroom or structured on-line instruction in the method — it is not on-the-job time. Experience is documented work time and is counted twice over: hours in the method being certified, and total hours in non-destructive testing generally. A candidate who has 700 hours of ultrasonics but only 900 hours of NDT in total still fails the Level II recommendation, because the total-hours column is 1200. Experience is counted on a nominal 40-hour week; time spent in the classroom is training, not experience, and cannot be claimed twice.

The spread between methods reflects how much of each method is judgement. Penetrant and magnetic particle Level I need only a few hours of classroom time because the technique is procedural and the indication is visible. Ultrasonics, radiography and eddy current need 40 hours at Level I and several hundred hours of hands-on time before a candidate can be trusted to interpret a signal, because in those methods the flaw is inferred from a trace rather than seen.

Where a candidate is certified straight to Level II without holding Level I, the recommendation is that training and experience be the sum of the Level I and Level II figures — the Level II row alone is written on the assumption that the Level I hours are already banked. The same logic applies when a candidate transfers methods: the total-NDT-hours column carries over, the hours-in-method column does not.

Worked example

NDT method	4
Level sought	2
Written-practice training override	0 h
Organised training completed	40 h
Experience logged in this method	300 h
Total NDT experience logged	800 h
NDT hours worked per week	40 h
Written-practice method experience override	0 h
Written-practice total NDT experience override	0 h
Recommended organised training	40 h
Recommended experience in method	630 h
Recommended total NDT experience	1200 h
Training shortfall	0 h
Method experience shortfall	330 h
Total NDT experience shortfall	400 h
Estimated weeks of work remaining	10

UT Level II, candidate already holds Level I. Table 6.3.1A gives 40 h training, 630 h experience in ultrasonics and 1200 h total NDT experience. Training: 40 − 40 = 0 h short. Method experience: 630 − 300 = 330 h short. Total NDT: 1200 − 800 = 400 h short. The binding shortfall is the larger of the two experience gaps, 400 h; at 40 h/week that is 400/40 = 10 weeks.

Use at your own risk — verify before you act

These calculators support, and never replace, the judgement of qualified NDT and engineering personnel. Results are provided as is, without warranty of any kind, express or implied, and must be independently verified against the governing code edition named in your contract before being used in any inspection, acceptance, rejection, radiation-safety or fitness-for-service decision. By using them you accept full responsibility for how the results are applied; NDT Inspect, its owners and contributors accept no liability for any loss, damage, injury or death arising from their use or from reliance on them. If a result matters to safety, check it by hand and have it reviewed by a competent person.