Probes for flaw detection and ultrasonic measurement

Translators for the contact inspection method

Straight beam-Single element

• Parts with regular geometry and relatively smooth contact surface
• Flat or curved contact surface
• Defect or background parallel to the surface or detectable with beam normal to the surface
• More suitable for penetrating thick sections
• Delay line designs improve near surface resolution
• Requires a coating layer, usually a gel, oil or paste
• Commonly used for manual inspection

Straight beam-Dual element (TR)

• Transmitter and receiver separated by crosstalk barrier
• Defect or background parallel or not to the surface or detectable with beam normal to the surface
• Ideal for thin sections, good near-surface resolution
• Requires a coating layer, usually a gel, oil or paste
• Commonly used for manual inspection

Angular beam

• Element-mounted or integral or interchangeable shoe
• Uses refraction to transmit a transverse or longitudinal wave at a predetermined angle
• Most standard transducers generate transverse waves by mode conversion
• Best suited to parts with inclined defects, such as welds
• Available in single and dual element models
• Requires a coating, usually a gel, oil or paste
• Sometimes used for mechanised or automated testing

Immersion translators

• Acoustically adapted for optimum efficiency in water
• Suitable for parts with irregular geometries
• Commonly used for mechanised or automated testing
• Optimum method for obtaining high performance coupling and reproducible results
• Large parts can be tested using translator holders, bubblers or water jets
• Translators can be focused to improve results

Focused immersion translators

• A spherical focus forms a focal point or focal spot
• A cylindrical focus forms a line
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• Advantages of focusing  
• Increases sensitivity to small defects
• Improves signal-to-noise ratio
• Improves near-surface resolution
• Good results on curved surfaces