Which inspection method uses a dye penetrant and ultraviolet light to reveal surface-breaking defects?

Which inspection method uses a dye penetrant and ultraviolet light to reveal surface-breaking defects?

• A. Visual inspection
• B. Fluorescent penetrant inspection
• C. Radiographic inspection
• D. Ultrasonic inspection

Answer: (B)

Fluorescent penetrant inspection uses a fluorescent dye penetrant that seeps into surface-breaking cracks. After excess penetrant is removed and a developer is applied, ultraviolet light causes the dye to glow, making even tiny surface cracks easily visible against a dark background. This combination of dye penetrant with UV illumination is specifically designed to reveal surface-breaking defects, which is why it’s the best choice. Other methods don’t use dye plus UV light: visual inspection relies on the naked eye, radiographic inspection uses X-rays to image internal features, and ultrasonic inspection uses high-frequency sound to detect flaws.

Fluorescent penetrant inspection uses a fluorescent dye penetrant that seeps into surface-breaking cracks. After excess penetrant is removed and a developer is applied, ultraviolet light causes the dye to glow, making even tiny surface cracks easily visible against a dark background. This combination of dye penetrant with UV illumination is specifically designed to reveal surface-breaking defects, which is why it’s the best choice. Other methods don’t use dye plus UV light: visual inspection relies on the naked eye, radiographic inspection uses X-rays to image internal features, and ultrasonic inspection uses high-frequency sound to detect flaws.