PA Technique and how to use

1. info@rd-tech.com • www.rd-tech.com
What Phased Arrays Can Do

2. Leader in Array Technology
How Phased Arrays Work
 This module illustrates typical scans that can be performed
using phased arrays:
 Electronic (originally called linear) scans
 Sectorial (azimuthal) or S-scans
 Transverse scans
 Dynamic Depth Focusing
 Time-of-Flight Diffraction
 With Tomoview or OmniScan software, operators can
custom-design their own scan patterns, displays and
outputs.

3. info@rd-tech.com • www.rd-tech.com
Electronic Scanning
Multiplex A Single Focal Law
Across the Array

4. Leader in Array Technology
Electronic Scanning
 The ability to move the beam along one
axis of an array without any
mechanical movement.
 The movement is performed only by
time multiplexing the active element
 The beam movement depends on the
probe geometry and could be a
 linear scanning
 sectorial scanning
 lateral scanning
 combination

5. Leader in Array Technology
Electronic Scanning
 Electronic (linear) scanning can easily emulate typical
ASME-type 45 and 60 shear wave inspections, and is much
faster than raster scanning.
 Typical weld inspection requires two or more angles with
implied raster size, step size, etc. Need to cover weld, HAZ,
any position errors => significant amount of scanning

6. Leader in Array Technology
Electronic Scanning on Circular Components
 Electronic scanning allows very quick scanning of
components with constant geometry, e.g., tubes,
pipes.

7. Leader in Array Technology
Tandem Probes for Vertical Defects

8. Leader in Array Technology
TOFD using Phased Arrays
Transmitter Receiver
Lateral wave
LW
Upper tip Lower tip
Back-wall reflection
BW

9. info@rd-tech.com • www.rd-tech.com
Sectorial (Azimuthal) or S-Scans
Changing the Inspection Angle
without Moving the Array

10. Leader in Array Technology
Illustration of Sectorial Scanning

11. Leader in Array Technology
Sectorial Scans (S-scans)
 Sectorial scanning is the ability to scan a complete sector
of volume without any probe movement.
 Useful for inspection of complex geometries, or those with
space restrictions
 Combines the advantages of a wide beam and/or multiple
focused probes in a single phased array probe

12. Leader in Array Technology
Sectorial Scans on Welds
 S-scanning – changing the incident angle without changing
position – can be used for a variety of inspections.
 Note some limitations on bevel angle incidence

13. Leader in Array Technology
Sectorial Scanning Animation
 This illustration shows a turbine blade root being inspected
using S-scans.

14. Leader in Array Technology
Turbine Welded Rotor Inspection
 Phased-array inspection:
 Sectorial scan 30-60 SW
 Step of 1 degree
 Linear scan along the
circumferential axis
 Phased-array probe:
 5 MHz, 16 elements,
16 mm × 16 mm
 Mounted on a wedge
 Calibration block:
 EDM notches
2 mm x 0.5 mm

15. Leader in Array Technology
Sectorial Scanning on Blade Root

16. Leader in Array Technology
Determining Defect Location

17. Leader in Array Technology
Defect Analysis using S-scans (1)
Crown
defect –
clearly
located
Defect tip
signal – easy
to identify
and size
T1 designation shows “top” or cap

18. Leader in Array Technology
Defect Analysis using S-scans (2)
B0 designation shows “bottom” or root
Corner
reflector
and crack
tip easily
measured

19. Leader in Array Technology
Combined scans -> improved POD

20. Leader in Array Technology
Combined S-Scan and Electronic Scan
 Combined scans
offer unique
imaging
possibilities
 Tomoview
software
enables
straightforward
set-ups

21. info@rd-tech.com • www.rd-tech.com
Lateral Scanning
Detecting Transverse Weld Defects

22. Leader in Array Technology
Lateral Scanning
1. Matrix arrays
2. Angled transverse array
3. Conventional UT and EPRI hybrids.

23. info@rd-tech.com • www.rd-tech.com
Dynamic Depth Focusing
Extending the Focal Range
Electronically

24. Leader in Array Technology
Schematic Representation of
Dynamic Depth Focusing
Mechanical Displacement
c = velocity in material
FOCUS DEPTH (PULSER)
DYNAMIC FOCUSING (RECEIVER)
Beam
displacement
DDF is an excellent way of inspecting thick components in
a single pulse. The beam is refocused electronically on its
return.

25. Leader in Array Technology
Dynamic Depth Focusing
Standard phased
array
Phased array with dynamic
depth focusing

26. Leader in Array Technology
Dynamic Depth Focusing Animation