This document provides an overview of phased array ultrasonic testing (PAUT). It begins with basic introductions to sound waves and their propagation. It then discusses PAUT in more detail, explaining that it uses multiple small transducer elements that can be pulsed separately to steer and focus sound beams electronically. The document outlines several beam scanning patterns and describes key PAUT system components. It also discusses advantages of PAUT over conventional UT and various types of phased array probes and their applications in inspecting welds, pipes, and other structures.

1. PHASED ARRAY ULTRA SONIC
TESTING ( PAUT )

2. Basic introduction of sound
What is sound?
sound is created through
vibrations in the air which causes
the auditory sensation in your ear

3. sound production : How it created
- through vibrations
sound propagation : How it travels
one place to another - waves

4. There are two main types of waves
• Transverse or shear wave
• Longitudinal wave

5. Wave form characteristics
Amplitude : how loud the signal is
Frequency : how often its
repeated
Velocity : the speed of
waveform
Wavelength : start to finish of the
sound

6. SNAELLS LAW
n1sinθ1 = n2sinθ2
θ1= Incident angle
θ2= refracted angle
v1= velocity in material 1
v2= velocity in material 2

7. • Infrasonic waves ( 0 hz to 20 hz )
• Audible waves ( 20 hz to 20000
hz )
• Ultrasonic waves ( above 20000
hz )

8. GENERAL INTRODUCTION OF PAUT
 ULTRASONIC TESTING USED IN
MEDICAL APPLICATIONS WITH
HIGHLY DETAILED CROSS
SECTIONAL PICTURES OF
INTERNAL ORGANS
(SONOGRAMS)

9.  RECENT YEARS PHASED ARRAY
SYSTEM HAVE BEEN INCREASING
IN INDUSTRIAL SECTORS TO
PROVIDE NEW LEVELS OF
INFORMATION &
VISUALISATION IN ULTRASONIC
TEST ( WELD INSPECTION,
CRACK DETECTION ETC...)

10.  PRINCIPLE OF CONSTRUCTIVE
AND DESTRUCTIVE
INTERACTIONS OF WAVES
DEMONSTRATED BY SCIENTIST
THOMAS YOUNG

11.  PHASE SHIFTING OR PHASING
IS IN TURN A WAY OF
CONTROLLING THESE
INTERACTIONS BY TIME
SHIFTING WAVEFRONTS
ORGINATES FROM TWO OR
MORE SOURCES ( BEND,STEER )

12. IN 1960 RESEARCHES BEGAN
DEVELOPING ULTRASONIC
PHASED ARRAY SYSTEM THAT
UTILIZE MULTIPLE POINT
SOURCE TRANSDUCER

13.  PROPERTIES
(METALS,COMPOSITES,CERAMIC
S,PLASTICS)

14. IN 1980 FIRST INDUSTRIAL
PHASED ARRAY SYSTEM
INTRODUCED

15. WHAT IS PHASED ARRAY SYSTEM
 CONVENTIONAL UT CONSIST
ONLY SINGLE CRYSTAL
 BUT IN PHASED ARRAY CONSIST
16-256 SMALL ELEMENTS THAT
PULSED SEPERATELY

16. TRANSDUCERS FREQUENCY ARE
MOST COMMONLY IN 2MHZ TO
10MHZ
P.A SYSTEM CAN SWEEP A
SOUND BEAM THROUGH
REFRACTED ANGLES AT
DIFFERENT DEPTH THUS
INCREASING BOTH FLEXIBILITY
AND CAPABILITY IN INSPECTION

18. HOW DOES ULTRASONIC PHASING WORK
 PHASED ARRAY SYSTEM
UTILIZES THE WAVE PHYSICS
PRINCIPLE OF WORKING
INDIVIDUAL WAVEFRONT
GENERATED BY EACH ELEMENT
IN ARRAY COMBINE EACH
OTHER

19. THIS ACTION ADDS OR CANCEL
EACH OTHER IN PREDICTABLE
WAYS THAT STEER & SHAPE
SOUND BEAM
 ELEMENTS ARE PULSED IN
GROUP OF 4 TO 32 IN ORDER TO
IMPROVE EFFECTIVE SENSITIVITY
BY INCREASING APERTURE,
WHICH THEN REDUCES
UNWANTED BEAM SPREADING
& ENABLES SHARPER FOCUSING

20.  FOCAL LAW CALCULATOR
ESTABLISH SPECIFIC DELAY
TIMES FOR FIRING EACH GROUP
OF ELEMENT IN ORDER TO
GENERATE DESIRED BEAM
SHAPE

21.  MAIN FEATURES OF PHASED
ARRAY ULTRASONIC TESTING IS
COMPUTER CONTROLLED
EXCITATION OF INDIVIDUAL
ELEMENT IN MULTI ELEMENT
PROBE

22. THREE MAJOR COMPUTER CONTROLLED
BEAM SCANNING PATTERNS
 ELECTRONIC SCANNING
DYNAMIC DEPTH FOCUSING ( DDF )
SECTORIAL SCANNING

23. Electronic scanning

24. Dynamic depth focusing (DDF)

25. Sectorial scanning

26. DELAY LAW OR FOCAL LAW
 FOCAL LAW DELAY FOR PROBES
WITHOUT WEDGE IN DIIRECT
CONTACT WITH THE TEST PIECE
WHICH WERE PROGRAMMED
TO GENERATE LONGITUDINAL
WAVES HAS PARABOLIC SHAPE
OF DEPTH FOCUSING

27. PHASED ARRAY PROBES
INSTALLED ON THE WEDGE
PROVIDE DELAY LAWS WITH
DIFFRENT SHAPED, BASED ON
FERMATS PRINCIPLE OF
MINIMUM ARRIVAL TIME
ALONG A SPECIFIC PATH

28. BASIC COMPONENTS OF P.A SYSTEM

29. ADVANTAGES OF PHASED ARRAY AS COMPARED
WITH CONVENTIONAL UT
 The benefits of phased array technology over conventional UT come
from its ability to use multiple elements to steer, focus and scan
beams with a single transducer assembly. Beam steering, commonly
referred to sectorial scanning, can be used for mapping components
at appropriate angles.
 P.A inspection speed can be as much as 10 times faster as compared
to conventional UT

30. DISADVANTAGES OF PAUT
 HIGH COST
 TRAINED TECHNICIAN

31. ULTRASONIC BEAM CHARACTERISTICS
TRANSDUCERS
• TRANSDUCERS WORK AS A PISTON
SOURCE OF HIGH FREQUENCY
MECHANICAL VIBRATIONS OR
SOUND WAVES
• A SINGLE PIEZO ELECTRIC CRYSTAL
CAN ACT AS BOTH TRANSMITTER
AND RECEIVER
TYPES
• CONTACT
• IMMERSION

32. SIZE
• SMALL DIAMETERS ARE EASILY
COUPLED WITH THE TEST PIECE
• LARGER DIAMETERS ARE
REQUIRED FOR DESIGN
REASONS
FREQUENCY
• THE NUMBER OF WAVE CYCLES
COMPLETED IN ONE SECOND IS
CALLED FREQUENCY

33. BANDWIDTH
• BANDWIDTH IS THE PORTION
OF FREQUENCY RESPONSE THAT
FALLS WITHIN SPECIFIED
AMPLITUDE LIMIT
• BROAD BANDWIDTH IS USUALLY
DESIRABLE IN THICKNESS
GAUGING APPLICATIONS
INVOLVING CONTACT,DELAY LINE
& IMMERSION TRANSDUCERS

34. WAVEFORM DURATION
• NUMBER WAVECYCLES
GENERATED BY THE TRANSDUCER
EACH TIME IT IS PULSED
• A NARROW BANDWIDTH
TRANSDUCER HAS MORE CYCLES
THAN A BROADER BANDWIDTH
TRANSDUCER
SENSITIVITY
• THE RELATIONSHIP BETWEEN
THE AMPLITUDE OF THE
EXCITATION PULSE AND THAT
ECHO RECEIVED FROM A
DESIGNATED TARGETS

35. BEAM PROFILING
• IN THE BEAM PROFILE
ILLUSTRATION RED REPRESENTS
AREA OF HIGHEST ENERGY,
WHILE GREEN AND BLUE
REPRESENT LOWER ENERGY
NEAR FIELD = A2/4λ
λ = V/F

36. ATTENUATION
• AS IT TRAVELS THROUGH A
MEDIUM, THE ORGANISED
WAVEFRONT GENERATED BY AN
ULTRASONIC TRANSDUCER BEGINS
TO BREAK DOWN DUE TO
IMPERFECT TRANSMISSION OF
ENERGY THROUGH THE
MICROSTRUCTURE OF ANY
MATERIAL
• ORGANISED MECHANICAL
VIBRATIONS ( SOUND WAVES )
TURN INTO RANDOM MECHANICAL
VIBRATIONS ( HEAT ) UNTIL THE
WAVEFRONT IS NO LONGER
DETECTABLE

37. PHASED ARRAY PROBE CHARACTERISTICS
TYPES
• P.A PROBES ARE OF ANGLE BEAM TYPE ( USE WITH EITHER PLASTIC WEDGE
OR STRAIGHT PLASTIC SHOE )
FREQUENCY
• 2 MHZ TO 10 MHZ
NUMBER OF ELEMENTS
• 16 -128 ( SOME HAVING AS MANY AS 256 )
SIZE OF ELEMENTS
• AS ELEMENT WIDTH GETS SMALLER, BEAM STEERING CAPABILITY
INCREASES, LARGE COVERAGE AREA ELEMENTS ARE HIGH COST

39. PIEZOCOMPOSITE MATERIALS
• The piezoelectric ceramic rods
are inserted in a polymer
material. The ceramic and the
resin are chosen according to
the characteristics required for
the composite material. The
geometry of the microstructure
itself can be adapted.
PZT POLYMER COMBINATION
(LEAD ZIRCONATE TITANATE)
• PZT + SILICONE RUBBER
• PZT + SPURS EPOXY
• PZT + POLYURETHANE
• PZT + REN EPOXY

40. MATCHING LAYER AND CABLE REQUIREMENTS
A GOOD CABLE SHOULD HAVE
FOLLOWING PROPERTIES
• MINIMUM GAIN DROP DUE TO
CABLE LENGTH
• LOW IMPEDENCE THE IDEAL IS
50Ω
• MECHANICAL ENDURANCE (
BENDING,MECHANICAL
PRESSURE,ACCIDENTAL DROP )
• WATER RESISTANCE FOR ALL
WIRES
• AVOID INTERNAL WIRE TWISTS

42. ACTIVE APERTURE ( A )
The active aperture (A) is the total
active probe length.
Aperture length is calculated by
the following formula:
A = n •p
where n = number of
elements in the PA probe
p = elementary
pitch—distance between the
centers of
two adjacent elements

43. MAIN LOBE
• THE MAIN LOBE IS ACOUSTIC
PRESSURE DIRECTED TOWARDS
THE PROGRAMMED ANGLE
SIDE LOBE
• SIDE LOBES ARE PRODUCED BY
ACOUSTIC PRESSURE LEAKING
FROM PROBE ELEMENTS AT
DIFFERENT AND DEFINED ANGLES
FROM THE MAIN LOBE
GRATING LOBE
• GRATING LOBES ARE GENERATED
BY ACOUSTIC PRESSURE DUE TO
EVEN SAMPLING ACROSS THE
PROBE ELEMENTS

44. PROBE ORDERING INFORMATION

48. WELD SERIES
A31 & A32 PROBES
• MANUAL AND AUTOMATED
INSPECTION OF 3MM TO 60MM
THICK WELD USING ANGLE
BEAM
• INNOVATIVE WEDGE DESIGN
AVAILABLE FOR SHEAR OR
LONGITUDINAL WAVES

49. SMALL DIAMETER PIPE WELDS (
COBRA )
A15 PROBES
• THIN WALL PIPES
• COVERS STANDARD PIPES FROM 21MM
TO 114MM OD (0.83 IN TO 4.5 IN)
• OPERATES WITHIN 12MM (0.5 IN)
CLEARENCE
• COBRA SCANNER HOLDS UPTO TWO
PHASED ARRAY PROBES FOR
COMPLETE WELD COVERAGE IN ONE
PASS

50. PROBES
• DUAL MATRIX ARRAY (A17,A27)
• SMALL FOOTPRINT PROBES (A00,A0,A10)
• PIPE LINE PROBES (PWZ1,A14,A16)
• DEEP PENETRATION PROBE (A3,A4,A5)
• NEAR WALL PROBES (NW1,NW2,NW3)
• IMMERSION PROBES (I1,I2,I3)
• CURVED ARRAY PROBES (R1,R4,R5)
• CODE COMPLAINT PROBES (DS1,SW1,AWS1)
• LEGACY PROBES (A1,A2,A11,A12)

51. Dual matrix array probe Small footprint probes
2.25DM7X4-A17 10L16-A00

52. Pipe line probes Deep penetration probes
3.5L16-A3
1.5L16-A4
5L32-A5
7.5L60-PWZ1

53. Nearwall probes Immersion probes
10L64-I1
5L64-NW1

54. Curved array probes Code compliant probes
4L16-DGS1
3.5CC25-R4

55. Legacy probes
5L64-A2

56. Edge FORM Probe
The Edge FORM phased array wheel probe
is used by automotive manufacturers to
inspect for voids in bonded or glued seams
in trunk, hoods, and door panels. It’s also
ideal for inspecting composites and other
smooth-surfaced materials.

57. Edge FORM Probe
• The probe’s zero-degree ultrasonic beams and built-in encoder
enable it to produce a clear C-scan image. If the bond is good,
sound energy is transmitted and attenuated in the glue and metal
sheets. If it’s bad, the sound is reflected back.
• Near-surface resolution up to 1 mm (0.04 in.)
• Inspect flat, smooth, and curved panels from 0.5 mm to 1.5 mm
(0.02 in. to 0.06 in.) thick

58. WELD SERIES
• A31 and A32 Probes
• Manual or automated
inspection of 3mm to 60mm
thick welds using angle
beams.
• Innovative wedge design
available for shear or
longitudinal waves.

59. Dual Array Probes for Welds
A17, A25, A26, and A27
Probes Stainless Steel Weld
Applications
• Corrosion-Resistant Alloy
(CRA).
• Stainless steel.
• Austenetic Material.
• Cladded Pipes.
• Dissimiliar Welds.

60. Dual Array Probes for Corrosion
This phased array solution
improves productivity through
features such as larger beam
coverage, faster scan speed,
and C-scan imaging with
increased data

61. Dual Array Probes for Corrosion
• The pitch-catch technique used
by this new probe offers better
near-surface resolution and pit
detection in corrosion survey
applications than standard
phased array pulse-echo,
improving the probability of
detection of critical wall
thinning.
• Detect defects as shallow as 1
mm (0.04 in.) below the surface.
• Typical inspection depth of 1 to
80 mm in carbon steel.

62. PITCH CATCH TECHNIQUE

63. Flexible Phased Array Probe
The FlexoFORM scanner uses
a flexible array probe to
perform corrosion inspection on
pipe elbows. The solution uses
a 64 element, 7.5 MHz, 1 mm
pitch probe with 7 mm
elevation positioned in a water
wedge that enables excellent
coupling on complex shapes
and helps protect the probe.

64. Small-Footprint Probes
Small-footprint probes offer
access to confined areas (A00
probe has an 8 × 8 mm footprint)
A special-design small-footprint
wedge is available for those
applications. Cable connector can
come out from either the side or
the top of these probes.

65. Universal Probes
The universal probes are designed to
have a low-profile probe/wedge
combination for easier access in
restricted areas. A wide selection of
wedges is available to suit any angle
beam application. These probes are
used for manual or automated inspection
of 6.35 mm to 38 mm thick welds and the
inspections of castings, forgings, pipes,
tubes, and machined and structural
components for cracks and welding
defects.
A10, A11, and A12 Probes

66. Near-Wall Probes
Near-wall probes offer a shortened dead
zone at both ends of the probe (1.5 mm
between center of first or last element and
housing edge). They are well suited for
composite channel inspections and are
used for C-scan inspections of
composites (delamination, disbonding,
and porosity).

67. Deep Penetration Probes
Deep penetration probes can be
matched to a wide selection of
wedges to suit any angle beam
application. These probes are
dedicated to deep penetration
applications such as the inspection
of thick plates and welds, forging,
and noisy or granular material.
A3, A4, and A5 probes

68. Deep Penetration Probes

69. Curves Array Probes
• Curved array probes are made
with a corrosion-resistant
stainless steel case and are
guaranteed waterproof up to 1
m underwater. The acoustic
impedance of these probes
matches water. They are
compatible with adjustable
immersion wedges and are
used for the inspection of
carbon fiber reinforced polymers
(CFRP) corners and in addition
to the inspection of composite
for delamination.

70. Curves Array Probes

71. WEDGES FOR ANGLE BEAM PROBES

74. PAUT FLAW DETECTOR

75. BASICS OF PHASED ARRAY IMAGING
• A SCAN DISPLAY

76. • B SCAN DISPLAY

77. • C SCAN DISPLAY

78. • S SCAN DISPLAY

80. SCANNING PATTERNS
• AUTOMATED
THE PROBE CARRIER IS MOVED BY A MOTOR CONTROLLED
DRIVE UNIT
• SEMI AUTOMATED
THE PROBE CARRIER IS MOVED BY HAND, BUT MOVEMENT IS
ENCODED
• MANUAL
PHASED ARRAY PROBE IS MOVED BY HAND AND DATA ARE
SAVED BASED ON ACQUASITION TIME

81. SCANNING PTTERNS FOR AUTOMATED AND
SEMIAUTOMATED INSPECTION
• BIDIRECTIONAL
• UNIDIRECTIONAL
• LINEAR
• SKEWED
• HELICAL
• SPIRAL
• CUSTOM

82. BIDIRECTIONAL SCAN
DATA ACQUISITION IS CARRIED OUT
IN BOTH THE FORWARD AND
BACKWARD DIRECTIONS ALONG THE
SCAN AXIS

83. UNIDIRECTIONAL SCAN
DATA ACQUISITION IS CARRIED OUT
IN ONE DIRECTION ONLY ALONG
THE SCAN AXIS

84. LINEAR SCAN
IT IS ONE AXIS SCANNING
SEQUENCE USING ONLY ONE
POSITION ENCODER TO
DETERMINE THE POSITION OF
ACQUISITION

85. SKEWED SCAN
THE SKEWED SCAN SEQUENCE IS A
FORM OF NORMAL BIDIRECTION
SCAN SEQUENCE
THIS SEQUENCE ALLOWS THE
SCAN AND INDEX PROBE PATH TO
BE SKEWED BY SOFTWARE
SELECTABLE ANGLE

86. HELICAL SCAN
IT IS USED TO INSPECT
CYLINDRICAL SURFACES
THE SCANNERS PERFORM A
HELICOIDAL MOVEMENT
AROUND THE CYLINDER

87. SPIRAL SCAN
THE SPIRAL SEQUENCE IS
DESIGNED TO INSPECT CIRCULAR
SURFACES SUCH AS DISC
SURFACES
THE INSPECTION
MECHANISMPERFORMS A SPIRAL
MOVEMENT ON A CIRCULAR
SURFACE

88. PHASED ARRAY TEST SETUP AND DISPLAY
FORMAT
• MATERIAL
• PROBE
• FREQUENCY
• BANDWIDTH
• SIZE
• NUMBER OF ELEMENTS
• ELEMENT PITCH
• WEDGE
• INCIDENT ANGLE OF WEDGE
• VELOCITY OF WEDGE
• INDEX OFF X = DISTANCE FROM
FRONT WEDGE TO 1ST ELEMENT
• SCAN OFF Y = DISTANCE FROM
SIDE OF WEDGE TO CENTER
ELEMENT

89. DA = DEPTH OF REFLECTOR IN
GATE A
PA = FORWARD POSITION OF
REFLECTOR WITH RESPECT TO TIP
OF WEDGE
RA = DISTANCE BETWEEN THE
WEDGE REFERENCE POINT AND
REFLECTOR
SA = SOUND PATH LENGTH TO THE
REFLECTOR

90. TYPES OF CALIBRATION
• VELOCITY (RADIUS,DEPTH,THICKNESS)
• WEDGE DELAY
• SENSITIVITY
• TCG ( TIME CORRECTION GAIN )
• ENCODER

91. PAUT TEST BLOCK
• PAUT RADIUS BLOCK
CALIBRATION

92. PACS BLOCK - 3/64 (1.2MM)
HOLES ALLOY

93. MINI PACS BLOCK

94. 6 IN MAX PACS ALUMINIUM
BLOCK

95. PACS NOTCH BLOCK

96. PHASED ARRAY TYPE A BLOCK

97. PSTM E2491 PA ASSESSMENT
BLOCK

98. PAUT IIW BLOCK, ISO 19675

99. PH TOOL PIPE CALIBRATION

100. PHASED ARRAY NAVSHIPS
TESTBLOCK 7075-T6

101. PA CALIBRATION BLOCK NO.2
(0.75 IN THICK)
ALLOY,STAINLESS STEEL
1018 STEEL,
7076 ALUMINIUM

102. PHASED ARRAY CALIBRATI0N
BLOCK NO.2 (1.5 IN) THICKNESS
ALLOY,STAINLESS STEEL
1018 STEEL,
7076 ALUMINIUM

103. P.A CALIBRATION BLOCK NO.3
(0.75 IN) THICK STEEL

104. CUSTOM P.A PROBES

105. PHASED ARRAY GLOSSARY
• ACG (ANGLE CORRECTION GAIN)
• APODIZATION
• APERTURE
• AZIMUTHAL SCAN
• BANDWIDTH
• BEAM FORMING
• BEAM SPREAD
• BEAM STEERING
• SENSITIVITY
• WEDGE DELAY
• FAR FIELD
• FOCAL LAW
• GRATING LOBES
• HUYGENS PRINCIPLE
• NEAR FIELD
• ONE LINE SCAN

106. • PHASED ARRAY
• PHASING
• PITCH
• PULSE DURATION
• SIDE LOBE
• VIRTUAL APERTURE