Immersion transducers

Enhanced focusing - FERMAT concept

Applications

• Inspection of thick parts and non-homogeneous materials
• Multizone billets inspection
• Thick plates inspection
• Heavy forged parts inspection
• Nuclear vessel inspection

Principle

The aspherically-focused active area is calculated to obtain the best focusing effect at a given location in the material with a given refracted angle, through a flat, cylindrical or toric interface.
Moreover, a wide transducer aperture combined with Fermat concept allows very high lateral resolution and signal-to-noise ratio.

It is typically used in immersion with pulse echo technique, but can also be used in contact with a delay line.

Advantages

• Very high resolution and signal-to-noise ratio
• Beam profile very close to simulation thanks to piezocomposite technology
• Fermat concept may be used on phased array probes, allowing flexible high-resolution beam focusing and beam scanning

Main Characteristics

• Piezocomposite technology
• Centre frequency (-6dB): from 1MHz to 15 MHz
• Relative bandwidth (-6dB): 60 to 90 %
• Acoustic impedance matched to water or delay line
• Watertight stainless steel housing

Options

• Customized wiring (cable length, type or positioning, connector type)
• Housing adapted to mechanical set-up (probe holder, wedge, etc)
• Adapted to environmental constraints (temperature, pressure, radiation, vibration, etc)