NDT composite examination grade

Qualification examinations for Level I and Level II are marked in three parts. The general examination covers the principles of the method and is not tied to any one product. The specific examination covers the equipment, procedures and acceptance criteria the candidate will actually work to, so it is written around the employer's own procedures and the codes in use. The practical examination puts the candidate on real hardware: set the equipment up, run the technique on specimens containing known discontinuities, and record the result on a report the Level III can audit.

The three marks are averaged into a composite grade, and there are two gates rather than one. Each part must reach 70 % on its own, and the composite must reach 80 %. The double gate exists because averaging alone would let a strong theory candidate hide a weak practical — and the practical is the part that reaches the weld. A candidate scoring 95, 95 and 55 averages 81.7 but is not certifiable, because the practical is below 70.

Because the composite is an average, the arithmetic works backwards usefully: with the general and specific results known, the practical mark needed to reach an 80 % composite is fixed, and it is often well above 70. Knowing that number before the practical is sat tells the candidate and the Level III whether more preparation is worthwhile.

Equal weighting of the three parts is the normal arrangement, but the employer's written practice governs and some practices weight the practical more heavily, or set pass marks above the recommended minima. A failed examination has a waiting period and a re-examination rule set by the written practice, and only the failed part is normally re-sat.

composite = (w_G·G + w_S·S + w_P·P) ÷ (w_G + w_S + w_P)
equal weights: composite = (G + S + P) ÷ 3
pass requires: min(G, S, P) ≥ 70 %  AND  composite ≥ 80 %
practical needed = [ composite_min·(w_G + w_S + w_P) − w_G·G − w_S·S ] ÷ w_P