What is the purpose of using different frequencies in ultrasonic testing?

In ultrasonic testing (UT), different frequencies are employed to tailor the inspection process for specific materials and types of flaws. Higher frequencies provide better resolution and can detect smaller flaws, making them suitable for inspecting thin materials or when precision is critical. However, higher frequencies have reduced penetration capabilities and may not effectively reach deeper into thicker materials.

Conversely, lower frequencies penetrate deeper and are better suited for testing thicker materials, although they may not detect small flaws with the same sensitivity as higher frequencies. This versatility allows technicians to optimize the effectiveness of ultrasonic testing based on the characteristics of the material being inspected and the type of defects being targeted. Thus, using different frequencies is essential for adapting the inspection to meet specific requirements and achieving accurate and reliable results across various applications.