What is the typical frequency range for ultrasonic waves used in UT?

The typical frequency range for ultrasonic waves used in ultrasonic testing (UT) is indeed between 0.5 MHz to 10 MHz. This frequency range is ideal for detecting internal flaws in materials and is commonly used for various applications in industrial NDT.

Frequencies in this range allow for better penetration of ultrasonic waves through materials and provide favorable sensitivity to small defects, as higher frequencies generally yield better resolution in distinguishing small flaws. Moreover, utilizing transducers that operate effectively within this frequency range contributes to more accurate measurements in thickness gauging and flaw detection.

Lower frequency ranges, such as those mentioned in the first option (1 kHz to 100 kHz), are typically associated with other forms of testing or applications where more significant depths of penetration are required, but they compromise resolution and sensitivity to smaller defects. Frequencies above 10 MHz may provide high resolution but can suffer from limited penetration capabilities in thicker materials, making them less suitable for most conventional UT applications. Thus, the established range of 0.5 MHz to 10 MHz strikes a balance between penetration depth and defect resolution, making it the standard choice for ultrasonic testing practices.