Which examination method uses high-frequency vibrations to locate defects?

Which examination method uses high-frequency vibrations to locate defects?

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

Answer: (B)

Ultrasonic testing uses high-frequency vibrations to locate defects by sending sound waves into a material and listening for echoes. A piezoelectric transducer generates the waves, which travel through the metal and reflect back when they hit flaws or the far surface. By measuring the travel time and echo strength, you identify the presence, depth, and size of a defect, even inside a weld. The frequencies used are typically in the megahertz range, enabling precise subsurface detection. Radiographic testing relies on penetrating radiation to create an image of internal features, not vibrations. Liquid Penetrant testing reveals surface-breaking cracks by capillary action of a penetrant dye, not sound waves. Magnetic Particle testing uses magnetic fields and iron particles to show surface and near-surface flaws, again not vibrations.

Ultrasonic testing uses high-frequency vibrations to locate defects by sending sound waves into a material and listening for echoes. A piezoelectric transducer generates the waves, which travel through the metal and reflect back when they hit flaws or the far surface. By measuring the travel time and echo strength, you identify the presence, depth, and size of a defect, even inside a weld. The frequencies used are typically in the megahertz range, enabling precise subsurface detection.

Radiographic testing relies on penetrating radiation to create an image of internal features, not vibrations. Liquid Penetrant testing reveals surface-breaking cracks by capillary action of a penetrant dye, not sound waves. Magnetic Particle testing uses magnetic fields and iron particles to show surface and near-surface flaws, again not vibrations.