PCN NDT Radiographic Testing Level 2 Exam study guide
PCN NDT Radiographic Testing Level 2 Exam · Work through your exam, one topic at a time.
PCN NDT Radiographic Testing Level 2 is a personnel certification for radiographers who can set up and perform radiographic inspections to a written procedure, select exposure techniques, produce and process images, interpret radiographs, and report results against an acceptance standard. It is aimed at inspectors and technicians in fabrication, castings, welding, aerospace, power generation and oil and gas, where radiographic testing is used to find internal discontinuities. The PCN NDT Radiographic Testing Level 2 Exam study guide has 8 sections and about 2,600 words.
01Principles of Radiography and Radiation Physics
X-rays are produced when electrons are accelerated across a tube and stopped in a target: a continuous bremsstrahlung spectrum plus sharp characteristic lines that appear only above the target element's excitation energy. Gamma rays come from nuclear decay and have discrete energies fixed by the isotope (Ir-192, Co-60, Se-75, Yb-169).
348 words, about 2 min02Radiation Safety, Protection and Dose Control
Radiation protection rests on justification, optimisation (ALARA) and dose limitation. Absorbed dose is measured in gray (J/kg); equivalent and effective dose in sievert, obtained by applying radiation weighting (1 for X and gamma rays) and tissue weighting factors.
333 words, about 2 min03Radiographic Equipment, X-ray Units and Gamma Sources
The tube has a filament cathode, a target anode, a focal spot, a window and both inherent and added filtration. Generators range from self-rectified and half-wave to constant potential; constant potential gives higher output and better definition at a given kV.
322 words, about 2 min04Imaging Media, Detectors and Film Processing
Radiographic film has a polyester base coated with silver halide emulsion in gelatin. Smaller grains give higher resolution and slower speed; larger grains give faster film and grainier images.
327 words, about 2 min05Technique Selection, Exposure Geometry and Technique Sheets
The technique must deliver the required image quality class for the material, thickness and geometry. The governing standard (ISO 17636-1 for film, ISO 17636-2 for digital, or ASME V Article 2) sets minimum source-to-object distance, maximum geometric unsharpness, number of exposures, IQI type and essential wire, and density range.
300 words, about 2 min06Image Quality, Sensitivity and Radiograph Interpretation
Image quality has three components: contrast, definition (sharpness) and freedom from graininess and artifacts. Radiographic contrast comes from subject contrast, film or detector gradient and scatter.
343 words, about 2 min07Discontinuity Detection, Evaluation and Acceptance Standards
Volumetric discontinuities - gas porosity, shrinkage, slag and inclusions - generally appear as dark, rounded or irregular spots whose darkness reflects lower attenuation. Planar discontinuities - cracks, lack of fusion, incomplete penetration - appear as sharp dark lines, often thin and aligned with the weld preparation.
316 words, about 2 min08Procedures, Reporting, Traceability and Quality Management
A written procedure describes what is done and why: scope, references, personnel requirements, equipment, surface preparation, technique, image quality checks, acceptance criteria, records and reporting. A technique sheet is the part-specific implementation.
311 words, about 2 min