Presentation On Phased Array UT in Lieu of Radiography

Phased Array Ultrasonic Testing (PAUT)

Presented by/ Credits to:

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Introduction to Ultrasonic Testing (UT)

Ultrasonic test instruments have been used in industrial applications for more than sixty years. Since the 1940s, the laws of physics that govern the propagation of high frequency sound waves through solid materials have been used to detect hidden cracks, voids, porosity, and other internal discontinuities in metals, composites, plastics, and ceramics, as well as to measure thickness and analyze material properties.

Sound waves are simply organized mechanical vibrations traveling through a medium. These waves will travel through a given medium at a specific speed or velocity, in a predictable direction, and when they encounter a boundary with a different medium they will be reflected or transmitted according to simple rules.

Conventional UT Probe Configuration

With a conventional UT probe, a single piezoelectric element converts an electrical signal into a mechanical vibration.

Source: NDT Resource Center (

Phased Array Ultrasonic Testing (PAUT)

ultrasound.jpgWhat we see in Medical Ultrasonic Test

What is the Difference in Medical Ultrasonogram

and Phased Array Ultrasonic Test?

Nothing Special, Both are Phased Array Ultrasonic Test

PA Image.jpg


Fetal Ultrasound - Full size.jpg


Phased Array Probe Configuration

  • Essentially, a phased-array probe is a long conventional probe

cut into many small elements, which are individually excited.


Phased Array Probe Configuration

  • It is like having many small conventional UT probes integrated inside a single probe.

128 elements !

How Does Phased Array Work?

Phased Array Angle Coverage

Angle beam covers from angle 40o to 70o with 1o angle increment.

Olympus EPOCH 1000i Phased Array Equipment

EPOCH 1000i

Epoch 1000i.jpg

A-Scan, S-Scan and C-Scan




Weld Overlay System

Full weld overlay system that enables to visualize the relative position of indications in relation to the weld geometry. Easily Configure the Weld Geometry in the equipment. Such as type of weld joint, weld preparation angle, bevel height, bevel width, root gap, root face, thickness of the specimen etc.

Defect Positioning

Defect Positioning


Defect Sizing


Image sizing cursors available for X2 – X1 and/or Y2 – Y1 indication sizing

    • Defect can be accurately sized
    • X-direction i.e. defect length
    • Y-direction i.e. defect depth

Report with complete information

Immediate report from the equipment can be transferable through pen drive.

Comparison of RT and PAUT

  1. Radiation safety
  2. Licensing
  3. Disruption to work area
  4. Chemical wastes
  5. Large volumes of film
  6. Film storage and deterioration
  7. Subjective interpretation
  8. Relatively slow inspection
  9. RT cannot size in vertical plane 10.RT poor at detecting planar defects.
  10. Phased Array Ultrasonic Testing (PAUT)

potentially offers solutions to ECA

  1. Capability of vertical sizing
  2. Better detection of critical planar defects
  3. Inspections tailored to weld profile and defects
  4. Generally PAUT has better detection than RT, especially for cracks
  5. Many trials performed globally
  6. Overall results support PAUT as better quality inspections.
    1. Higher licensing costs for RT
    2. Major headaches in shipping and storing isotopes
    3. Higher cost in waste disposal, storage etc.
    4. Cheaper PAUT Inspection Cost
    5. No film cost in PAUT
    6. No chemical cost in PAUT
    7. No production interruption in PAUT.

Comparison of Scan Times between PAUT vs. RT


1 man

1 min

12 to 15

Root Crack

Phased Array Image


Phased Array Image


Phased Array Image

Lack of Root Fusion

Phased Array Image

Concave of Root

Phased Array Image

PAUT vs. RT Advantages

PAUT vs. RT Advantages

  1. Many functional advantages from switching from


  1. No radiation
  2. No licensing
  3. No chemical wastes
  4. Less subjective data interpretation
  5. Minimizes data storage problems
  6. Minimizes materials handling issues
  7. Minimizes production disruptions
  8. Better detection of planar defects
  9. Can size in vertical plane for ECA
  10. Lower reject rates
  11. Fast and cost effective

PAUT Code Updates


  1. ASME Code Case N- 659-2 permits Phased Array Ultrasonic Testing (PAUT) for Replacement of RT with PAUT for feeder tubes in nuclear reactor.
  2. ASME CC 2541 Permits Phased Array Ultrasonic Testing (PAUT) in Section V, Article 4.
  3. ASME CC 2235-9 permits UT in lieu of RT in Section VIII, Divisions 1 and 2.
  4. ASME CC 2557 permits PAUT S-Scan in Section V, Article 4.
  5. ASTM has published three Standard Practices: 2491, 2700, 2904
  6. ISO, Chinese, Japanese working on PAUT codes.

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