Total Focusing Method (TFM)
How does TFM Work?
The Total Focusing Method (TFM) is an ultrasonic array technique which is used to synthetically focus at every point of a region of interest.
Details
1st Step: Data Collection with Full Matrix Capture (FMC)
- Full Matrix Capture (FMC) is another way of collecting phased array data
- This technique doesn’t require any knowledge of the piece to be inspected (nor shape, nor velocities)
- Each element is just activated (shot) one by one
- All the elements in reception are recorded and thus a Matrix of signal is stored in order to be processed
2nd Step: Reconstruction: Total Focusing Method (TFM)
Main Advantages of TFM
- Optimal focusing and spatial resolution everywhere
- Direct imaging of a large area for one probe position
- All reachable angles with the array simultaneously
- Defect characterisation
- Comprehensive imaging of defect
- 3D imaging
Comparison with Electronic Scanning
Electronic scanning
- 8-element aperture
- Focused along the defects in the middle
- 57 shots
TFM
- 64-element aperture
- Focused everywhere
- 64 shots
Electronic scanning
TFM
Comparison with Sector Scanning
Sectorial scanning
- 64-element aperture
- Focused along the defects in the middle
- Sectorial between -55° and 55° with 110 shots
TFM
- 64-element aperture
- Focused everywhere
- 64 shots
Sector scanning
TFM