Which nondestructive testing method detects internal flaws within a weld?

Which nondestructive testing method detects internal flaws within a weld?

• A. Visual inspection detects surface defects; UT detects internal flaws.
• B. UT detects surface defects; Visual detects internal flaws.
• C. Radiography detects internal flaws; Visual detects cosmetics.
• D. Magnetic particle detects color variation; Dye penetrant detects cracks.

Answer: (A)

Non-destructive testing methods reveal different kinds of defect information in welds. Ultrasonic testing sends high-frequency sound into the weld; when these waves hit internal flaws like lack of fusion, porosity, or cracks, they reflect back to the probe. That reflection lets you detect internal flaws and estimate their size and depth without cutting the weld. Visual inspection, on the other hand, looks at the surface and will miss subsurface issues unless they are visible on the exterior. So saying that surface inspection covers surface defects and ultrasonic testing detects internal flaws accurately describes how these methods work together to assess weld quality. Other choices mix up what each method can detect—surface-focused techniques like magnetic particle or dye penetrant are best for surface or near-surface features, while radiography can image inside but isn’t as concise a pairing for internal flaws in this context.

Non-destructive testing methods reveal different kinds of defect information in welds. Ultrasonic testing sends high-frequency sound into the weld; when these waves hit internal flaws like lack of fusion, porosity, or cracks, they reflect back to the probe. That reflection lets you detect internal flaws and estimate their size and depth without cutting the weld. Visual inspection, on the other hand, looks at the surface and will miss subsurface issues unless they are visible on the exterior. So saying that surface inspection covers surface defects and ultrasonic testing detects internal flaws accurately describes how these methods work together to assess weld quality. Other choices mix up what each method can detect—surface-focused techniques like magnetic particle or dye penetrant are best for surface or near-surface features, while radiography can image inside but isn’t as concise a pairing for internal flaws in this context.