SNT-TC-1A training and experience hours

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.

training required = Table 6.3.1A (method, level)
experience in method = Table 6.3.1A (method, level)
total NDT experience = Table 6.3.1A (method, level)
direct to Level II:  hours = Level I hours + Level II hours
written-practice overrides replace the table values where entered
shortfall = max(0, required − logged)
weeks remaining ≈ ceil( max(method shortfall, total shortfall) ÷ hours per week )