Phased Array Probe

• The PA probe consists of many small elements, each one can be pulsedon

separately.

P/RTrig

P/RDelayP/RDelay

P/RDelayP/RDelay

P/RDelayP/RDelay

P/RDelayP/RDelay

TrigCrystal

CrystalCrystal

CrystalCrystal

CrystalCrystal

CrystalCrystal

Conventional Probe Phased Array Probe

Phased Array Probe

• The PA probe consists of many small elements, each one can be pulsedon

separately.

P/RTrig

P/RDelayP/RDelay

P/RDelayP/RDelay

P/RDelayP/RDelay

P/RDelayP/RDelay

TrigCrystal

CrystalCrystal

CrystalCrystal

CrystalCrystal

CrystalCrystal

Conventional Probe Phased Array Probe

Constant

distance

Weld Inspection

• The whole weld area can be covered with only one probe at a fixed position.

Simulation

Overlay

• Sensitive to cracks at various orientations

• Portability

• Safety

• Able to penetrate thick sections

• Measures depth and through wall extent

Advantage of Phased Array Technology

• Higher Inspection Sensitivity

• Faster Inspection Efficiency

• Stronger Inspection Capacity

• Accurate Flaw Positioning

• Visual Inspection Result

• No permanent record (unless automated)

• Not easily applied to complex geometries and rough surfaces.

• Unsuited to course grained materials

• Requires highly skilled and experienced technicians

• Electromagnetic radiation is imposed upon a test object

• Radiation is transmitted to varying degrees dependant upon

the density of the material through which it is travelling

• Variations in transmission detected by photographic film or

fluorescent screens

• Applicable to metals,non-metals and composites

Lower

density

Higher

density

Radiation Source

Film

Specimen

Placing Film to be radiographed

Isotopes produce Gamma rays

Examples: Co60, Ir192, Yb169

X-Ray Tube

Panoramic

Single Wall Single Image

Double Wall Double Image

• Safety

X-ray machines is normally safer: can be switched off/on

Gamma source: constant emission

• Capabilities

Gamma source have very high penetrating power

X-ray: intensity and wavelength can be adjusted

• Quality of images

In general: x-ray produces better quality

• Handling

Gamma sources are easier to handle

X-ray machine are bulky, fragile and requires electricity

• Cost

Gamma source are cheaper

• Permanent record

• Detection of Internal flaws

• Can be used on most materials

• Direct image of flaws

• Real - time imaging

• Health hazard

• Sensitive to defect orientation

• Limited ability to detect fine cracks

• Access to both sides required

• Limited by material thickness

• Skilled interpretation required

• Relatively slow

• High capital outlay and running costs

• Transient stress waves from micro structural changes

detected by sensors

Stress waves

Stress

Quality in execution of NDT operations demands attention to a series of

interlinked aspects extending from research and development, codes and

standards, equipment, personnel training and certification to the effects of

human reliability and the influence of auditing and surveillance. These

aspects can be represented as links in a chain as shown in Figure 1.

• Several years ago the two approaches to approval and

certification (central, independent, third party and in-company)

were seen as very different there now seems to be a gradual

convergence of the two. Users of central certification are

increasingly aware of the need for the central certification to

be used in the correct way - as part of an organisation’s quality

systems for NDT or written practice - and the guidelines for in-

house, company based certification are bringing in requirements

for external assessment e.g. independently certified Level 3s.

• * What do you think the Important factor in determining the

Quality of NDT Results

• HUMANThe UK’s PANI (Programme for the Assessment for NDT in Industry) projects have

shown the variability in performance between ultrasonic operators of similar

experience and qualification. PANI 2 showed that improvements in reliability can be

obtained by the use of targeted procedures, job specific training and independent

repeat inspections. PANI 3 which is due to be published has found a correlation

between good ultrasonic performance and operators with good mechanical

comprehension. There is also a correlation between good ultrasonic performance and

operators with an average level of cautiousness and lower levels of original thinking.

This project has also highlighted the importance of ensuring that the inspection

procedure is written in a way that assists the operator in the task and that the

operator follows the procedure.

CERTIFICATIONS AND QUALIFICATIONS

NDT personnels should posses high credibility and integrity

Proper training and certification required

•Training : By qualified training personnels and accredited training centres

•International Certification Schemes available:

•ISO 9712:2011-? Will be the need

Currently, there are 28 laboratories accredited mainly

for the following techniques:

• PT

• MT

• UT

• RT

The industries which the NDT laboratories are serving

largely in the oil & gas, petrochemical and general

engineering industries

• Following Best Practices & with adequate qualified NDT

personnel, we would be able to come out with Quality assured

NDT Results.

• Thank you

• Q & A

• VISIT US & SUPPORT US TO JOIN

• SINGAPORE INTERNATIONAL NDT CONFERENCE & EXHIBITION 2011 – NOVEMBER 3- 4

• THEME: NDT FOR SAFER WORLD

• 2 Days event, Proceedings, Lunch & Tea provided

• HOLIDAY INN ATRIUM

• AUTRI MEMBERS REGISTRATION FEE $200.00

• NON MEMBERS REGISTRATION FEE $250.00

• For Registration , Please visit

• www.ndtss.org.sg