What does the bimodal ultrasonic testing method primarily target?

The bimodal ultrasonic testing method primarily targets flaws located in the mid-wall region of a material. This technique is designed to detect discontinuities that may be present between the surface and the midsection of a material, providing a detailed examination of this critical area. The mid-wall region is often susceptible to various types of defects that can arise during manufacturing or service, such as inclusions, porosity, or lack of fusion in welds.

By focusing on this specific area, bimodal ultrasonic testing can enhance the detection capabilities of inspectors compared to conventional methods, which may not effectively identify flaws located deeper within the material. This approach uses two different ultrasonic frequencies or modes to enhance the resolution and sensitivity of the testing, allowing for a more thorough assessment of potential defects that could compromise the integrity of the material.