What is the frequency range most commonly used in commercial ultrasonic testing?

The frequency range most commonly used in commercial ultrasonic testing falls between 0.2 to 25 megahertz. This range is selected because it effectively balances the ability to detect flaws and the penetration depth of the ultrasonic waves. Lower frequencies, such as those closer to 0.2 MHz, can penetrate deeper into materials and are thus useful for thicker sections, while higher frequencies, moving up to 25 MHz, provide better resolution and sensitivity for detecting smaller flaws in thinner materials.

In the context of commercial applications, this frequency range is widely accepted as optimal across various industries, including manufacturing, aerospace, and construction for testing various materials such as metals, plastics, and composites. Frequencies outside this range, either much lower or much higher, might not be effective for typical applications, leading to either insufficient resolution or inadequate penetration capabilities.