Which examination method uses ionizing radiation to reveal internal discontinuities?

Which examination method uses ionizing radiation to reveal internal discontinuities?

• A. Radiographic
• B. Ultrasonic
• C. Magnetic Particle
• D. Liquid Penetrant

Answer: (A)

Radiographic examination uses ionizing radiation to reveal internal discontinuities. X-ray or gamma-ray beams pass through the weld and surrounding metal, and regions with flaws such as porosity, slag inclusions, cracks, or voids attenuate the radiation differently. The resulting image shows internal features as varying dark and light areas, allowing inspectors to see flaws that aren't visible on the surface. This is why radiography is the go-to method when the goal is to detect internal defects in welds. Ultrasonic testing relies on high-frequency sound waves, which reflect off internal boundaries to indicate flaws, but it does not involve ionizing radiation. Magnetic particle testing uses magnetic fields and iron particles to reveal surface and near-surface defects in ferromagnetic materials, not internal flaws across the thickness. Liquid penetrant testing shows surface-breaking defects by dye seeping into cracks and becoming visible on the surface, also not revealing internal discontinuities.

Radiographic examination uses ionizing radiation to reveal internal discontinuities. X-ray or gamma-ray beams pass through the weld and surrounding metal, and regions with flaws such as porosity, slag inclusions, cracks, or voids attenuate the radiation differently. The resulting image shows internal features as varying dark and light areas, allowing inspectors to see flaws that aren't visible on the surface. This is why radiography is the go-to method when the goal is to detect internal defects in welds.

Ultrasonic testing relies on high-frequency sound waves, which reflect off internal boundaries to indicate flaws, but it does not involve ionizing radiation. Magnetic particle testing uses magnetic fields and iron particles to reveal surface and near-surface defects in ferromagnetic materials, not internal flaws across the thickness. Liquid penetrant testing shows surface-breaking defects by dye seeping into cracks and becoming visible on the surface, also not revealing internal discontinuities.