Angle-Beam Probe
An angle-beam probe couples ultrasonic energy through a plastic wedge to produce a refracted shear or longitudinal wave at a fixed angle (typically 45°, 60°, or 70°) in the test piece, used primarily for weld inspection.
Definition
An angle-beam probe consists of a longitudinal-wave element bonded to a plastic wedge cut so that Snell's law refracts the wave into the test piece at a desired angle. By choosing the wedge angle, inspectors generate refracted shear waves at 45°, 60°, or 70° — the canonical weld-inspection angles.
Related terms
- Shear Wave — A shear wave is an ultrasonic mode in which particle motion is perpendicular to the direction of propagation; in steel, shear waves travel at ~3,250 m/s and are produced by mode conversion at angled wedges for weld inspection.
- Normal-Beam Probe — A normal-beam probe (0°) launches a longitudinal wave perpendicular to the test surface, used primarily for thickness measurement and for detecting laminar defects parallel to the surface.
- Mode Conversion — Mode conversion is the partial conversion of an ultrasonic wave from one mode (longitudinal, shear, surface) to another at a refracting or reflecting interface, governed by Snell's law and the angle of incidence.
- Transducer (Ultrasonic) — An ultrasonic transducer is a device — typically containing a piezoelectric element — that converts electrical pulses to mechanical vibrations and vice versa, used to launch and receive ultrasonic waves in the test piece.
Further reading
shear wave ut for thick section inspection
More equipment terms
Calibration Block · Dual-Element Probe · Couplant · Reference Reflector · Side-Drilled Hole · Flat-Bottom Hole · Notch Reference · X-Ray Tube · Gamma Source · Iridium-192
Where this comes up in practice
Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.
Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.