For a round element the near-field length is N = D²f / 4v, for diameter D, frequency f and wave speed v. For phased arrays the used aperture plays the role of D. The workbench reports the near field in the wedge, converts it to path in the part with the wedge/part velocity ratio and marks where it ends.
Focusing inside the near field gives the sharpest beams; beyond it the beam diverges.
Other topics
- Probe and wedge
- Beamsets
- Part and weld
- Calibration blocks
- Custom parts
- Indications
- Pressure map, delay view and wave animation
- Wedge designer
- Zonal coverage
- Reports
- Files and exports
- Workspace files
- Results pane
- Focal laws
- Focus types
- Near field
- Beam spread
- Weld editor
- Zone naming
- Pipes and curved parts
- Calibration templates
- Drawing editor basics
- Snaps
- Layers
- Trim and extend
- Part templates
- Quality maps
- Full-matrix capture and A-scans
- Time-of-flight diffraction
- High-temperature wedges
- Drawing export
- Probe, wedge and transducer files
- View controls
- Options
- Units
- Report templates
- Layout editor
- Word export
- Accounts and access
- Keyboard shortcuts
- Transducer fields
- Indication types
- Warnings
- Technician guide: from part to plan