Which of the following improves resolution in ultrasonic testing?

In ultrasonic testing, resolution refers to the ability to distinguish between closely spaced reflectors or to identify small details within a material. Using a higher frequency transducer is effective in improving resolution because higher frequency waves have shorter wavelengths. The shorter wavelengths can detect smaller features and provide greater detail in the ultrasonic images.

Higher frequency sound waves result in better resolution because they can separate closely spaced flaws or changes in material properties more effectively than lower frequency waves. While a lower frequency transducer can penetrate deeper into a material, it does so at the cost of resolution because the longer wavelengths make it more challenging to distinguish between fine details.

Increasing the pulse duration and reducing the sound path length also impact the quality of ultrasonic testing, but they do not directly enhance resolution in the same way that a higher frequency transducer does. In fact, longer pulse durations might lead to reduced resolution due to the overlap of echoes from two closely spaced reflectors. Reducing sound path length is important for other performance factors but does not inherently improve the resolution capability of the system.