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ADVANCE
ULTRASONIC
INSPECTION
DACON INSPECTION TECHNOLOGIESEddy CurrentArray technology
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingConventional vs Array
Conventional Eddy Current surface testing
Advantages compared to alternatives (PT/MT):
• No paint removal
• Fast
• Environmental friendly (no use of chemicals)
• Indication of depth of defects
• Small probe• Confusing signal
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingConventional vs Array
Array Eddy Current surface testing
Advantages of ETA compared to conventional ET
• Increased coverage
• Easy to understand data presentation
• Permanent record
• Increased POD
• Encoded scans
• Big probe• Easy C-scan
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingConventional vs Array
ConventionalManual raster single coil
ET arrayWide coverage by sequential excitation
of multiple coils
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
ETA Surface testingProbe explained
• Elements are the individual EC probes used to make the array probe.
• Any type of EC probe can be used as an element. For example:
• Pencil probe:
• Sliding probe:
…1 2 32
+ =Corrosion array
…1 2 32
+Surface array
=
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingProbe explained
Absolute bridge probe
Double row array
• Uniform sensitivity over the probe width
• Improved resolution that allows smaller defect detection.
• Needs an encoder to align the data in the C-scan.
• Smaller coverage for the same number of elements. Coverage
Resolution
Single row array
• Non uniform sensitivity
• Low sensitivity to cracks parallel to scan direction and between elements
Coverage
Resolution
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingProbe explained
Omni directional probe
• Sensitivity for defects in each direction
• Axial and transverse channel required to find all defects
Axial channels Transverse channels
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingWeld inspection
ConventionalMultiple scans
ET arraySingle encoded scan
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingCovering a surface
ConventionalOverlapping manual scans
ET arrayMultiple encoded scans creating a C-
scan image
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingApplications and probes
Different applications need different probes
• Surface probes
• Rigid and flexible
• Far surface corrosion
• Near and sub- surface cracks
• 5 KHz frequency
• Weld scan probes (non ferrous)
• Padded probes
• Short surface breaking cracks
• 250 or 500 KHz available
• Complex geometry probes
• Very flexible (I flex)
• Far surface corrosion
• Near and sub- surface cracks
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
Surface testingApplications and probes
Different applications need different probes
• Weld scan probes (Ferrous)
• Sharck Pobe
• Carbon steel welds
• Detecting cracks in Cap, Toe and HAZ
• Sizing of cracks up to 10 mm deep
• Tangential Arrays
• Coils positioned on their side
• Axis of coil parallel to surface
• Transmit receive mode
• Eddy current parallel to surface
• Capable of dicing under a crack
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
ETA tube inspection
Advantages over conventional bobbin coil tube inspections
• More sensitive to circumferential cracking
• Provides information on circumferential extent of defect
• Better accuracy for gradual (absolute) wall loss
• Can distinguish between defect signal and tube sheet signal
• No need for additional testing of tube ends for
circumferential cracking by rotating techniques
• If only testing tube ends 5 sec per tube vs 40 sec per
tube for rotating techniques
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
ETA tube inspection
Sensitivity to circumferential cracking
Bobbin coil
• Eddy currents travel in
circumferential direction
• Eddy currents not
significantly disturbed by
circ. crack
Array
• Eddy currents travel parallel to the
surface
• Eddy currents are perpendicular to circ.
Crack, significantly disturbed
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
ETA tube inspection
Def Hi probes
• Bobbin coils
• Arrays
• Single
or
• double
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
ETA tube inspectionGradual wall loss
Bobbin coil Array
DACON INSPECTION TECHNOLOGIES
DACON INSPECTION SERVICES F O R A L L Y O U R I N S P E C T I O N N E E D S
How Can We Help?
Contact
Email : [email protected]
Phone : +66 (0) 33 012 484-7
www.dacon-inspection.com
DACON INSPECTION TECHNOLOGIES