ASNT NDT III RT case studies
ASNT NDT III RT · Put your knowledge to work in context.
The ASNT NDT Level III Radiographic Testing (RT) credential is a professional certification offered by the American Society for Nondestructive Testing, one of several methods ASNT names among the common NDT disciplines alongside UT, PT, MT, ET, and AE. It is aimed at experienced radiographic testing personnel who already hold Level II competence and are moving into roles that require method-level technical judgment: technique selection and qualification, procedure writing and review, interpretation of codes and specifications, acceptance decisions, and supervision or training of Level I and Level II staff. The ASNT NDT III RT case studies are 5 cases and about 3,097 words.
1Source-to-Object Distance vs. Geometry Unsharpness on a Thick Nozzle Weld
You are the Level III reviewing a technique for a 75 mm thick carbon steel nozzle-to-shell weld. The current technique uses an Ir-192 source at 400 mm source-to-object distance (SOD), a 3.0 mm focal spot, D7 film with Pb screens, and a 2.0 mm geometric unsharpness limit per your written practice.
678 words, about 3 min2Film Density and IQI Sensitivity Failure on a Dissimilar Thickness Weld
A fabrication shop is radiographing a 25 mm to 12 mm transition weld in stainless steel using X-ray at 220 kV. The technique specifies D4 film, 0.025 mm Pb front and 0.1 mm Pb back screens, density 2.0-2.5, and a 2-2T hole-type IQI placed on the source side.
748 words, about 4 min3Geometric Unsharpness vs. Penetrameter Placement on a Complex Casting
You are radiographing a 40 mm thick steel casting with a complex internal cavity using Ir-192. The part cannot be rotated easily, and the only accessible source position gives an SOD of 350 mm.
560 words, about 3 min4Scatter and Backscatter on a Pipe Weld with a Lead Screen Failure
A crew is radiographing a 150 mm diameter, 12 mm wall carbon steel pipe weld with Ir-192 using a single-wall single-image technique. The films show a foggy, low-contrast image with a dark band along one edge.
559 words, about 3 min5Source Decay, Exposure Time, and Technique Validity Across a Long Project
A project uses an Ir-192 source that was 80 Ci at calibration 120 days ago. The technique sheet was written at calibration and specifies a 4-minute exposure for a 30 mm steel weld at 500 mm SOD with D7 film and density 2.3.
552 words, about 3 min