A sound beam that hits a surface at an angle will reflect forward at the same angle. A sound beam that hits a surface at perpendicular incidence will reflect straight back. In situations where sound reflects off a boundary, the angle of reflection equals the angle of incidence. Sound energy at ultrasonic frequencies is highly directional and the sound beams used for flaw detection are well defined. In the case of angled discontinuities, a properly selected angle beam assembly can direct sound at a favorable angle for reflection back to A variety of specific beam angles and probe positions are used to accommodate different part geometries and flaw types. The angled sound beam is highly sensitive to cracks perpendicular to the far surface of the test piece (first leg test) or, after bouncing off the far side, to cracks perpendicular to the coupling surface (second leg test). A perpendicular crack will reflect angled sound energy along a path that is commonly referred to as a corner trap, as seen in the illustration below. An angle beam assembly directs sound energy into the test piece at a selected angle. This situation can occur in many types of welds, in structural metal parts, and in many other critical components. Perpendicular cracks do not reflect any significant amount of sound energy from a straight beam because the beam is looking at a thin edge that is much smaller than the wavelength, and tilted cracks may not reflect any energy back in the direction Is a brief review of the theory of angle beam testing, along with some notes and tips intended to assist users.Ĭracks or other discontinuities perpendicular to the surface of a test piece, or tilted with respect to that surface, are usually invisible with straight beam test techniques because of their orientation with respect to the sound beam. Consultation Reception about IntroductionĪngle beam assemblies, consisting of a transducer and a wedge, are extremely important to the field of ultrasonic nondestructive testing, commonly used in a wide variety of weld inspection applications and also for detection of cracks oriented perpendicular to the surface in metal plates, pipes, billets, and forgings, as well as machined and structural components.OEM Microscope Components for Integration.Semiconductor & Flat Panel Display Inspection Microscopes ▾.Aerospace/Wind Blade Inspection Scanners.Flaw Detectors / Phased Array Flaw Detectors ▾.Thickness and Flaw Inspection Solutions ▾.
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