Non-Destructive Testing (NDT) Practice Test

In its most common applications, what does ultrasonic testing primarily use?

1. Low frequency sound energy

2. High frequency sound energy

3. Infrared radiation

4. X-rays

The correct answer is: High frequency sound energy

Ultrasonic testing primarily uses high frequency sound energy, typically in the range of 1 to 20 MHz, to identify defects and irregularities in materials. This method is highly effective because high frequency sounds can penetrate materials with great precision and provide detailed information about the internal structure without causing any damage. The ability to detect minute flaws, such as cracks, voids, or inclusions, relies on the properties of sound waves. High frequency waves have shorter wavelengths, which is advantageous in resolving small defects, as well as providing higher resolution imaging and accurate analysis of thickness variations in materials. In contrast, options such as low frequency sound energy, infrared radiation, and X-rays do not align with the principles and methodologies used in ultrasonic testing. Low frequency sound waves are typically less effective in detecting small features within materials. Infrared radiation relates to thermal testing practices, and X-rays are associated with radiographic testing, which involves a different approach to inspecting material integrity.