OmniScan SX \MX2 Training Program
Phased Array Analysis –Flaw Characterization
V4.3R2
OmniScan SX\MX2 Training –Analysis –Flaw Characterization Overview
Flaw characterization is defined as the ability to identify flaw types and geometry
based on failure mechanism, location, and imaging.
Knowledge of the weld process is extremely helpful. You can eliminate porosity or
slag as a possibility for processes that do not produce them.
For some weld bevel types and processes typical of the pipeline industry >90% of
the defects are either lack of side wall fusion or inadequate penetration.
In-service inspections are typically for cracks and metal loss. Although cracks can
occur in any environment new construction welds are primarily for fabrication
defects such as IP, LOF, LOSWF, slag, porosity, etc.
It is normally necessary to have participated in the data acquisition to be proficient in
the analysis due to differences in weld processes and inspection conditions from
one job to another. The exception to this is factory or fabrication facilities were
welds of the same process, configuration, and size are inspected repeatedly.
There is no substitute for experience. The benefit of analysis on welds for which the
inspector is familiar or for which testing was performed on notches or SDHs in the
weld cannot be overcome with software features and training.
OmniScan SX\MX2 Training –Analysis –A-scan \S-scan Imaging
Weld flaws can be classified as either planer or volumetric based on their unique A-
scan imaging and characterization.
Volumetric flaws such as slag, porosity, and cracks with multiple ligaments will be
characterized in the A-scan as having a long rise and fall time on the time base.
(Also called a long echo dynamic)
Volumetric flaws are characterized by multiple peaks and facets of varying
amplitude typically embedded in the middle volume of the weld.
Volumetric flaws are often best detected in the second leg skipping off the inner
surface.
Volumetric flaw example (Porosity cluster)
OmniScan SX\MX2 Training –Analysis –A-scan \S-scan Imaging cont.
Planer flaws such as inadequate penetration, lack of root fusion, lack of side wall
fusion, will be characterized in the A-scan as having a very short rise and fall time or
short echo dynamic on the time base.
Planer flaws are characterized by high amplitude sharp signals that are orientation
dependent and fall rapidly upon probe skew.
Planer flaws can be embedded or surface connected and are most likely to generate
a sharp tip diffracted signal for precision measurements.
Planer flaw example (Lack of fusion)
OmniScan SX\MX2 Training –Analysis –A-scan \S-scan Imaging
The benefit of traditional conventional UT A-scan characterization techniques
combined with the color imaging and volumetric location that is available in the
phased array S-scan makes for a powerful inspection that is less dependent on the
skill and experience of the inspector.
Differentiating between planer and volumetric defects can often be the deciding
factor for a repair given that planer flaws represent a more serious defect with tighter
sizing criteria.
No single factor should weigh more heavily than location while characterizing flaws
and separating them from geometric indications.
Planer flaw example (Rejectable SW lack of fusion)Volumetric flaw example (Acceptable porosity cluster)
OmniScan SX\MX2 Training –Analysis –Flaw Characterization Overview
The 3 primary indicators in determining flaw type in typical weld inspections in
descending order or priority are:
1.Flaw location.
2.A-scan and S-scan imaging and characterization.
3.When accessible and available, was the flaw detected from both sides of the weld?
What type of flaw is pictured below and why?
OmniScan SX\MX2 Training –Analysis –Flaw Characterization Overview cont.
No single factor should weigh more heavily than its location. In this case based on
the flaw occurring in the middle volume of the weld and its appearance in the A-scan
and S-scan, porosity or slag is suspected.
Slag and porosity are volumetric defects that will produce a longer echo dynamic or
rise and fall time on the A-scan time base.
Orientation and low amplitude relative to its size is counter indicative of non fusion
so a volumetric defect is suspected.
TF_5_Slag.Opd
If the probe can be
skewed slightly from
side to side, confirm
volumetric defect by
long A-scan echo
dynamic and
multiple peaks of
varying amplitude.
OmniScan SX\MX2 Training –Analysis –Flaw Characterization Overview cont.
Moving the scan axis data cursor on the C-scan or B-scan allows a dynamic view of
the A-scan and S-scan at different positions along the weld line.
Not isolated or cluster porosity based on a continuous line at same depth.
Not LOF based on amplitude, counter indicated S-scan image, and location.
The flaw is a low amplitude slag line contained within one weld pass.
21 3 54
21 3 54
OmniScan SX\MX2 Training –Analysis –TF_5_Slag.Opd
From the same data point, select the A-B-C-S layout and use the B-scan to
characterize the slag line across the scan axis to visualize the flaw at each focal law
and depth.
Select the angle on the title bar and use the OmniScan rotary knob or mouse wheel
to scroll through the focal laws while observing the B-scan and repositioning
cursors.
The B-scan provides more confirmation that this is a slag line and not porosity or
non fusion.
B-scan (Current focal law only)
C-scan (All focal laws) S-scan
A-scan
Slag line
OmniScan SX\MX2 Training –Analysis –TF_5_Slag.Opd cont. FIX length
A 20mm slag line is contained within 1 weld pass (2mm) at the same depth (5mm)
along the weld line at varying amplitude.
1.Flaw amplitude (A%): 44.6% measured at 38.5mm scan, 59 degrees.
2.Flaw volumetric position: +.11mm
3.Embedded\Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 36.02mm
5.Flaw end on scan axis (Sm): 56.49mm
6.Flaw length (Sm-r): 20.46mm
7.Flaw depth (DA): 5.17mm
8.Flaw upper extremity (Ur): 17.93mm
9.Flaw lower extremity (Um): 19.84mm
10.Flaw height (Um-r): 1.91mm
11.Flaw type: Slag line
OmniScan SX\MX2 Training –Analysis –TF_12_ID_Crack.Opd
Open the file and move the axis data cursor to 50mm scan axis and 58.5 degrees,
then zoom in tight on the S-scan over the crack area.
Drag the top of the color bar scale from 100% to 46% and observe the center of the
energy of the crack tip.
The color palette can also be manipulated in >Display>Properties>Category: Color
Palette>46%.
Place the red Ur cursor at 7.80mm and the green Um cursor at 12.70mm.
OmniScan SX\MX2 Training –Analysis –TF_12_ID_Crack.Opd cont.
Select the A-B-C-S layout and on the S-scan zoom in on the area of interest of the
crack adjacent to the weld like pictured below.
The image below is at 50mm scan axis, 58.5 degrees, color palette end= 46.
The angle data cursor on the title bar is used to scroll through the focal laws with the
while observing the crack image on the B-scan.
Observe the crack profile across the scan axis at different depths. The signals in the
B-scan are ligaments of the crack generating diffracted energy.
Position the red Sr cursor and green Sm cursor at the crack extremities on the C-
scan and B-scan.
B-scan (58.5 degree focal law only) 58.5 degree A-scan
Crack ligaments
B-scan crack imaging
Crack ligaments
OmniScan SX\MX2 Training –Analysis –TF_12_ID_Crack.Opd cont.
A 31mm long ID connected crack is detected and sized in a 12.7mm V weld. There
are two relative data points. One of the crack base and one for the crack tip.
1.Flaw max amplitude (A%): 59.1% measured at 41mm scan, 51.5 degrees. (Crack base)
2.Flaw volumetric position: -4.15mm measured at 50mm scan, 58.5 degrees. (Crack tip)
3.Embedded \Surface connected?: Inside surface connected
4.Flaw start on scan axis (Sr): 31mm
5.Flaw end on scan axis (Sm): 62mm
6.Flaw length (Sm-r): 31mm
7.Flaw depth (DA): 7.80mm
8.Flaw upper extremity (Ur): 7.80mm
9.Flaw lower extremity (Um): 12.70mm
10.Flaw height (Um-r): 4.90mm
11.Flaw type: HAZ crack
OmniScan SX\MX2 Training –Analysis –TF_7_Porosity.Opd
An 11mm long porosity cluster is detected and sized in a 12.7mm V weld. 3
individual porosity pores can be seen as the data cursor is moved on the scan axis.
1.Flaw max amplitude (A%): 62.6% measured at 50mm scan, 61 degrees.
2.Flaw volumetric position: +0.76mm
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 44.5mm
5.Flaw end on scan axis (Sm): 55.5mm
6.Flaw length (Sm-r): 11mm
7.Flaw depth (DA): 8.68mm
8.Flaw upper extremity (Ur): 14.5mm
9.Flaw lower extremity (Um): 18.60mm
10.Flaw height (Um-r): 4.10mm
11.Flaw width (Im-r): 2.66mm
12.Flaw type: Porosity cluster
1.Flaw max amplitude (A%): 62.6% measured at 50mm scan, 61 degrees.
2.Flaw volumetric position: -.039 measured at flaw tip, 80mm scan, 67 degrees.
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 76mm
5.Flaw end on scan axis (Sm): 98mm
6.Flaw length (Sm-r): 22mm
7.Flaw depth (DA): 20.45mm
8.Flaw upper extremity (Ur): 19.93mm
9.Flaw lower extremity (Um): 23.47mm
10.Flaw height (Um-r): 3.54mm
11.Flaw type: Lack of fusion
OmniScan SX\MX2 Training –Analysis –PA Weld.Opd Flaw 1
A 22mm long embedded lack of fusion indication is detected and sized in a 25mm V
weld.
OmniScan SX\MX2 Training –Analysis –PA Weld.Opd Flaw 2
32mm of side wall lack of fusion is detected and sized in a 25mm V weld.
1.Flaw max amplitude (A%): 118.6% measured at 175mm scan, 54 degrees.
2.Flaw volumetric position: -8.52mm
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 154mm
5.Flaw end on scan axis (Sm): 186mm
6.Flaw length (Sm-r): 32mm
7.Flaw depth (DA): 11.33mm
8.Flaw upper extremity (Ur): 40.27mm
9.Flaw lower extremity (Um): 32.24mm
10.Flaw height (Um-r): 8.03mm
11.Flaw type: Lack of side wall fusion
OmniScan SX\MX2 Training –Analysis –PA Weld.Opd Cap Geometry
Cap geometry noted in C-scan and S-scan throughout weld. Data point below is at
110mm, 56 degrees.
1.Flaw max amplitude (A%): NA.
2.Flaw volumetric position: NA
3.Embedded \Surface connected?: NA
4.Flaw start on scan axis (Sr): NA
5.Flaw end on scan axis (Sm): NA
6.Flaw length (Sm-r): NA
7.Flaw depth (DA): NA
8.Flaw upper extremity (Ur): NA
9.Flaw lower extremity (Um): NA
10.Flaw height (Um-r): NA
11.Flaw type: Non relevant -geometry
OmniScan SX\MX2 Training –Analysis –PA Weld.Opd Cap Geometry cont.
Use the A-B-C-S layout to scroll through the focal laws while observing the B-scan
image zoomed at T1.
Compare this characterization of geometry vs. cracks and non fusion as the image
is displayed across the scan axis on the C-scan.
Cap geometry noted in C-scan and S-scan throughout weld. Data point below is at
110mm, 56 degrees.
OmniScan SX\MX2 Training –Analysis –PA Weld.Opd Flaw 3
34mm of side wall lack of fusion is detected and sized in a 25mm V weld.
1.Flaw max amplitude (A%): 52% measured at 242mm scan, 57 degrees.
2.Flaw volumetric position: 14.81mm measured at crack tip at 248mm scan, 59 degrees.
3.Embedded \Surface connected?: Outside surface connected
4.Flaw start on scan axis (Sr): 232mm
5.Flaw end on scan axis (Sm): 258mm
6.Flaw length (Sm-r): 26mm
7.Flaw depth (DA^1): 6.97mm
8.Flaw upper extremity (Ur): 43.06mm
9.Flaw lower extremity (Um): 50.00mm
10.Flaw height (Um-r): 6.97mm
11.Flaw type: Toe crack
OmniScan SX\MX2 Training –Analysis –PA Weld.Opd Flaw 3 cont.
B-scan imaging of the crack tip ligaments across the scan axis. Use the OmniScan
rotary knob or mouse wheel to scroll through the relative focal laws while observing
the B-scan.
248mm scan axis, 58 degrees.
B-scan (59 degree)
Deepest crack ligament
Deepest crack ligament
OmniScan SX\MX2 Training –Analysis –TF_21_Porosity.Opd
A porosity cluster 25mm long X 6.28mm wide is detected at a depth of 4.12mm with
a through wall dimension of approximately 2 weld passes.
1.Flaw max amplitude (A%): 52% measured at 58mm scan, 57.5 degrees.
2.Flaw volumetric position: -1.07mm
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 47mm
5.Flaw end on scan axis (Sm): 72mm
6.Flaw length (Sm-r): 25mm
7.Flaw depth (DA): 4.12mm
8.Flaw upper extremity (Ur): 17.24mm
9.Flaw lower extremity (Um): 21.80mm
10.Flaw height (Um-r): 4.56mm
11.Flaw width (Im-r): 6.28mm
12.Flaw type: Porosity cluster
OmniScan SX\MX2 Training –Analysis –TF_21_Porosity.Opd cont.
Select the A-B-C-S layout and use the OmniScan rotary knob or mouse wheel to
scroll through the focal laws while observing the crack profile across the scan axis
on the B-scan.
Use 58mm scan axis, 57.5 degrees, and zoom to generate B-scan view below.
B-scan (Current focal law only)
C-scan (All focal laws)
OmniScan SX\MX2 Training –Analysis –TF_21_Porosity.Opd cont.
Low level cluster porosity noted intermittently through out weld < evaluation and
recording threshold. (Pictured below is +13dB over reference sensitivity)
17mm scan axis, 58.5 degree data point pictured below.
OmniScan SX\MX2 Training –Analysis –TF_21_Porosity.Opd cont.
Loss of coupling noted between 18-22mm.
OmniScan SX\MX2 Training –Analysis –TF_28_ID Crack.Opd
Using a one line scan, a 10mm long ID crack is detected with a through wall
dimension of 2.64mm.
1.Flaw max amplitude (A%): 97.1% measured at 52mm scan, 59.5 degrees.
2.Flaw volumetric position: -2.35mm measured at 51mm scan, 61 degrees.
3.Embedded \Surface connected?: ID connected
4.Flaw start on scan axis (Sr): 48.5mm
5.Flaw end on scan axis (Sm): 58.5mm
6.Flaw length (Sm-r): 10mm
7.Flaw depth (DB^1): 22.35mm
8.Flaw upper extremity (Ur): 22.36mm
9.Flaw lower extremity (Um): 25.00mm
10.Flaw height (Um-r): 2.64mm
11.Flaw type: ID connected crack
OmniScan SX\MX2 Training –Analysis –TF_28_ID Crack_ProveUp.Opd
Pictured below are images from the same crack in the previous slide.
Left is original unfocused one-line scan and right is an optimized manual inspection.
Manually optimizing the probe index position and skew + focusing at flaw depth will
always produce better results than one line scans and is sometimes necessary for
critical components or where precision sizing is required for an acceptance decision.
Crack height measured from 16 element one line scan = 2.65mm
Crack height measured from optimized 32 element manual inspection = 3.36mm
Original one line scan crack image (Unfocused w\16 element aperture) Manual prove up of crack (Optimized focus w\32 element aperture)
TF_28_IDcrack.Opd TF_28_IDcrack_ProveUp.Opd
1.Flaw max amplitude (A%): 125.6% measured at 9mm scan, 56 degrees.
2.Flaw volumetric position: 2.12mm.
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 4mm
5.Flaw end on scan axis (Sm): 13mm
6.Flaw length (Sm-r): 9mm
7.Flaw depth (DA): 1.89mm
8.Flaw upper extremity (Ur): 8.20mm
9.Flaw lower extremity (Um): 7.20mm
10.Flaw height (Um-r): 1mm
11.Flaw type: Embedded
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd Flaw 1
Multigroup layout visualizing side wall lack of fusion detected on skew 270 group 2,
9mm long X 1mm high.
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd Flaw 1 cont.
The same flaw as previous slide displayed in the single group A-B-C-S layout.
Zoomed and optimized for flaw length, depth, and height sizing.
No single factor should be weighted more than location for characterizing flaws.
It is normal that side wall lack of fusion is only detected from near side only due to
defect orientation.
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd Flaw 2
Multigroup layout visualizing OD connected crack on skew 270 group 2, 10mm long
X <1mm deep. No clear distinguishable diffracted tip signal on main crack section.
1.Flaw max amplitude (A%): 142.5% measured at 37mm scan, 43 degrees.
2.Flaw volumetric position: 6.29mm
3.Embedded \Surface connected?: OD connected
4.Flaw start on scan axis (Sr): 34.5mm
5.Flaw end on scan axis (Sm): 44.5mm
6.Flaw length (Sm-r): 10mm
7.Flaw depth (DA): <1mm
8.Flaw upper extremity (Ur): 8.60mm
9.Flaw lower extremity (Um): 9.60mm
10.Flaw height (Um-r): <1mm
11.Flaw type: OD connected crack
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd Flaw 2 cont.
The same flaw as previous slide displayed in the single group A-B-C-S layout.
Zoomed and optimized for flaw length, depth, and height sizing.
Crack ligaments detected at 40mm scan, 43 degrees <1mm in depth \height.
Length sizing verified by scrolling through focal laws with rotary knob or mouse
wheel while observing flaw profiled across scan axis of B-scan.
S-scan at 40mm, 43 degrees
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd Flaw 3
Multigroup layout visualizing OD connected crack on skew 270 group 2, 10mm long
X <1mm deep. No clear distinguishable diffracted tip signal.
1.Flaw max amplitude (A%): 71.6% measured at 123mm scan, 63 degrees.
2.Flaw volumetric position: -1.15mm
3.Embedded \Surface connected?: ID connected
4.Flaw start on scan axis (Sr): 119.5mm
5.Flaw end on scan axis (Sm): 126mm
6.Flaw length (Sm-r): 6.5mm
7.Flaw depth (DA): 4.45mm
8.Flaw upper extremity (Ur): 4.15mm
9.Flaw lower extremity (Um): 4.80mm
10.Flaw height (Um-r): <1mm
11.Flaw type: Lack of root fusion
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd Flaw 3 cont.
The same flaw as previous slide displayed in the single group A-B-C-S layout.
Zoomed and optimized for flaw length, depth, and height sizing.
Flaw depth and height <1mm. No clear distinguishable tip signal.
Very close subjective call that this flaw is not ID connected. If ID connected, a
higher amplitude signal would be expected based on notch evaluation.
OmniScan SX\MX2 Training –Analysis –TF_CobraSS304.Opd -Repeatability
The last 2 flaws seen in group 2 skew 270 C-scan below are the same flaws as 1
and 2 on the second revolution around the pipe.
This level of repeatability is only possible with a precision scanner such as the
Olympus Cobra with A15 CCEV probes.
Verify the repeatability by performing length, depth, and height sizing on the flaws in
the second revolution of this sample data file.
11
22
OmniScan SX\MX2 Training –Analysis –TF_26_IP.Opd
Inadequate penetration typically does not require depth and height sizing and is only
evaluated based on amplitude and length sizing.
1.Flaw max amplitude (A%): 145.6% measured at 70mm scan, 54 degrees.
2.Flaw volumetric position: -1.16mm
3.Embedded \Surface connected?: ID connected
4.Flaw start on scan axis (Sr): 64.5mm
5.Flaw end on scan axis (Sm): 82mm
6.Flaw length (Sm-r): 17.5mm
7.Flaw depth (DB): NA
8.Flaw upper extremity (Ur): NA
9.Flaw lower extremity (Um): NA
10.Flaw height (Um-r): NA
11.Flaw type: Inadequate penetration
1.Flaw max amplitude (A%): 80.2% measured at 20mm scan, 50.5 degrees.
2.Flaw volumetric position: -4.83mm measured at crack tip at 21mm scan, 53 degrees.
3.Embedded \Surface connected?: ID connected
4.Flaw start on scan axis (Sr): 15mm
5.Flaw end on scan axis (Sm): 35mm
6.Flaw length (Sm-r): 20mm
7.Flaw depth (DB^1): 21.32mm
8.Flaw upper extremity (Ur): 21.31mm
9.Flaw lower extremity (Um): 25mm
10.Flaw height (Um-r): 3.69mm
11.Flaw type: ID connected crack
OmniScan SX\MX2 Training –Analysis –TF_ID_Crack3.Opd
Multiple tips are detected at or near the same depth. Put the cursor on the data
point in #2 below and move the scan cursor while observing the A-scan and S-scan.
Select the A-B-C-S can view, select the angle cursor from the title bar and scroll
through the focal laws observing the B-scan.
This data view is very useful for length sizing as the crack profile for each focal law
is displayed across the scan axis.
OmniScan SX\MX2 Training –Analysis –TF_ID_Crack3.Opd cont.
50.5 degree B-scan50.5 degree B-scan
C-scan (All focal laws)
Crack ligaments
Each pixel in the C-scan below represents 1 data point.
The color of the pixel is based on the maximum amplitude detected in gate A.
What is the fastest way to find the data point of highest amplitude in the C-scan
below?
OmniScan SX\MX2 Training –Analysis –TF_ID_Crack3.Opd cont.
Adjust the color palette for the maximum contrast and then slowly lower the end%
until one or more pixels turns red. (Start=33, End=82 in example below)
This can be done directly on the vertical color palette scale at the end of the C-scan.
Use the rotary dial on the instrument or a mouse wheel for fastest analysis.
OmniScan SX\MX2 Training –Analysis –TF_ID_Crack3.Opd cont.
1.Flaw max amplitude (A%): 99.8% measured at 49mm scan, 67 degrees.
2.Flaw volumetric position: -.91mm
3.Embedded \Surface connected?: ID connected
4.Flaw start on scan axis (Sr): 33mm
5.Flaw end on scan axis (Sm): 53mm
6.Flaw length (Sm-r): 10mm
7.Flaw depth (DB): NA
8.Flaw upper extremity (Ur): NA
9.Flaw lower extremity (Um): NA
10.Flaw height (Um-r): NA
11.Flaw type: Inadequate penetration
OmniScan SX\MX2 Training –Analysis –TF_14_IP.Opd
Inadequate penetration typically does not require depth and height sizing and is only
evaluated based on amplitude and length sizing.
OmniScan SX\MX2 Training –Analysis –TF_29_LOF.Opd
In the lack of fusion defect below, it is not possible to know the upper flaw position
on the UT axis due to access limitations without grinding the weld crown.
1.Flaw max amplitude (A%): 104.5% measured at 41mm scan, 67.5 degrees.
2.Flaw volumetric position: 3.30 mm
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 36.5mm
5.Flaw end on scan axis (Sm): 46.5mm
6.Flaw length (Sm-r): 10mm
7.Flaw depth (DB): 6.94mm
8.Flaw upper extremity (Ur): Unknown
9.Flaw lower extremity (Um): 9.33mm
10.Flaw height (Um-r): Unknown
11.Flaw type: Lack of fusion
?
1.Flaw max amplitude (A%): 81.8% measured at 61mm scan, 54.5 degrees.
2.Flaw volumetric position: -6.61mm
3.Embedded \Surface connected?: Embedded
4.Flaw start on scan axis (Sr): 54.5mm
5.Flaw end on scan axis (Sm): 64.5mm
6.Flaw length (Sm-r): 10mm
7.Flaw depth (DA): 3.96mm
8.Flaw upper extremity (Ur): 20.90mm
9.Flaw lower extremity (Um): 19.03mm
10.Flaw height (Um-r): 1.87mm
11.Flaw type: Lack of side wall fusion
OmniScan SX\MX2 Training –Analysis –TF_23_SWLOF.Opd
The orientation of the lack of fusion side wall fusion below makes a -6dB drop sizing
technique ideal for an accurate measurement. Use the color palette.
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V4.3R2