86511176 ultrasonic testing in accordance with aws d1 5 asme v

7/30/2019 86511176 Ultrasonic Testing in Accordance With AWS D1 5 ASME V

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Course Outline for

Ultrasonic Testing in Accordance

with AWS D1.1 and ASME VPrerequisites:

Completion of ASNT SNT-TC-1A

recommended training for UT Level I & II

qualification; i.e., 80 hours. Some anglebeam experience preferred.

Course Duration:

The course is offered in 1-5 day blocks.

Generally speaking, a person with limited

angle beam experience will take longer to

complete the curriculum; i.e., calibrate,

detect, plot and record, interpret and

evaluate all recordable indications. K2

Technologies will maintain records ofattendance and examination documents for

each student. A certificate ofcompletion

will be issued for successful detection;

dimensioning and recording of a minimum

of ten weld discontinuities.

Course Description:

This course is designed to provide the

operator with an understanding of

interpreting signals and characterizing

flaws with angle beam ultrasonic

examination in accordance to the AWS

D1.1 and the ASME V codes.

Course Objective:

Upon completion of the course the

participant will be able to:

1. Reference appropriate sections of

both codes.2. Interpret ultrasonic signals and

characterize various indications

related to welds.

3. Calibrate the ultrasonic instrument in

accordance with the codes.

4. Interpret; Evaluate and Record weld

discontinuities in accordance with

the codes.

5. Gain confidence and efficiency inperforming ultrasonic weld

inspection.

6. Examine several test pieces of

various geometries and successfully

detect, dimension and record a

minimum of ten weld discontinuities.

7. Pass a written examination specific

to the aforementioned codes.

Course Outline:1. A General section that discusses

ultrasonic weld testing, flaw sizing

and characterization of weld flaws.

2. An AWS D1.1 section that covers

specific calibration and examination

techniques to this code.

3. An ASME V section that covers

specific calibration and examination

techniques to this code.

Course material and test samples provided.

Equipment Arrangements are available.

Course Prepared by:

Ken L. Heaps

3400 Glenn Don Cr

Anchorage AK 99504

[email protected]

ASNT NDT III UT/MT/PT/LT/RTAWS CWI; API 570; 653 NACE

See attached files UT Angle Beam #1 - #5
mailto:[email protected]:[email protected]


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References: ................................................................................................................................................... 2Math Review .................................................................................................................................................2

Trigonometry ................................................................................................................................. 2

Near Field: .................................................................................................................................. 2Beam Spread ............................................................................................................................... 2Circumferential Scanning Formula............................................................................................. 2

dB equation ................................................................................................................................. 3Wavelength: ................................................................................................................................ 3

Areas: .......................................................................................................................................... 3

Using a calculator: ...................................................................................................................... 3Velocity Chart: ............................................................................................................................................... 3General Discussion of Ultrasonic Sizing of Flaws ........................................................................................5Interpreting Signals .......................................................................................................................................6

Rise and Fall Time...................................................................................................................... 6

Peaks ........................................................................................................................................... 6Signal Base.................................................................................................................................. 7

Tip Diffracted.............................................................................................................................. 8Transmit Receive ........................................................................................................................ 8

Characterizing Indications in Welds..............................................................................................................8Root Indications (surface connected).......................................................................................... 8

Midwall Indications (subsurface) ............................................................................................. 11Weld Cap Indications (surface connected) ............................................................................... 11

Interpretation Tips for Non-relevant and False Indications.........................................................................12Refracted L-wave Indications ................................................................................................... 12

Creeper Wave Indications......................................................................................................... 12Standing Wave Indications ....................................................................................................... 12

Pre Inspection Requirements......................................................................................................................13Physical Measurements............................................................................................................. 13Calculate Distances................................................................................................................... 13

Mark Surface Distances on Plate Adjacent to Weld................................................................. 13

Weld Profile/Sound Path Transparency.................................................................................... 13Basic Angle Beam Calibration ....................................................................................................................14

Sweep Distance:........................................................................................................................ 14

Sensitivity ................................................................................................................................. 14APPENDIX A: AWS D1.1............................................................................................................................16APPENDIX B: ASME V...............................................................................................................................17Quiz Questions:............................................................................................................................................. 1

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K2 Technologies Rev 1 05/01/04Page 1 of 1


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References:ASME V Article 4 & 5AWS D1.1 Section 6 & Annexes

ASTM E164

Math Review

Trigonometry

SP = T/cos0: 1st

leg Sound PathSP = 2 x (T/cos0): Full V Sound PathSD = SP x sin0: Surface DistanceT = SP x cos0: 1st Leg DepthT = 2 x (T [SP x cos0]): 2nd Leg DepthT = (SP x cos0) (2 x T): 3rd Leg Depth

SD Full V

SP 2nd leg

TSP 1st leg

SP 3rd leg

Figure 1. Sound Path, Surface Distance, Thickness

Near Field:

N = D2 x F

(4 x V)Keep velocity in microseconds to cancel out frequency exponents. Near fieldcalculations are important when dimensioning flaws because they can mask tipdiffraction signals.

Beam Spread

SIN0 = 1.22 ( / D)The sin value for angle beam spread equals 1.22 x wavelength divided by

diameter. Its a sin value so you need to do a sin-1 function to convert it back into adegree value. Beam spread plots may be required and they should always besupported by a Near Field and Beam Spread calculations. The 1.22 constant plotsthe theoretical beam edge. 1.09 constant for 12 dB.

Circumferential Scanning Formula

SIN01 = (ID/OD) x SIN02

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Calculates the required refracted angle (01) to produce desired refracted angle (02)at the inside diameter of the component. Enter the desired angle of refraction at IDfor SIN02; SIN01 is the wedge angle required to achieve the desired angle.SIN02 = SIN01 / (ID/OD)

To determine angle of refraction at ID for a known wedge angle.

dB equation

dB = 20 x log(Amp%2/ Amp%1)Used to determine the db difference between two amplitudes.

Wavelength:

= V/FKeep velocity in microseconds to cancel out frequency exponents. Flaws can bereliably detected only when greater than wavelength.

Areas:

Area of circle = pi x radius2

Area of rectangle = length x height

Using a calculator:

Make sure calculator is set to Degrees, NOT Radians & NOT Gradients. Degreeunits used in formulas are sin values. To convert sin value back to degree uses thesin-1 of the sin value.

Velocity Chart:

Longitudinal Shear AcousticVelocity Velocity Impedance

Material

Air 0.013 0.33 - - 0.0004

Aluminum 0.25 6.3 0.12 3.1 17

Alumina Oxide 0.39 9.9 0.23 5.8 32

Beryllium 0.51 12.9 0.35 8.9 23

Boron Carbide 0.43 11 - - 26.4

Brass 0.17 4.3 0.08 2 36.7

Cadmium 0.11 2.8 0.059 1.5 24

Copper 0.18 4.7 0.089 2.3 41.6

Glass (crown) 0.21 5.3 0.12 3 18.9

Glycerin 0.075 1.9 - - 2.42

Gold 0.13 3.2 0.047 1.2 62.6

Ice 0.16 4 0.08 2 3.5

Inconel 0.22 5.7 0.12 3 47.2

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General Discussion of Ultrasonic Sizing of FlawsA full volumetric weld inspection consists of propagating ultrasound throughout the entire weldmetal volume and heat affected zone (HAZ) in a cross pattern; i.e., each angle used is propagated

from both sides to achieve the cross pattern using the 1st

and 2nd

legs as diagramed below. If

access is limited to only one side of the weld then a 2nd and 3rd leg exam is performed to achievethe same cross pattern. Whenever possible, use the first leg of sound path in all weld

examinations.

The ASME Section V, Articles 4 and 5 and AWS D1.1 Annex K codes require flaw

dimensioning using decibel (dB) drop sizing methods; e.g., a 50% amplitude drop. It has been

demonstrated that when the flaw isless than the beam spread, the dB

drop sizing method tends to

dimension the beam profile instead

of the actual flaw size, therebyover sizing the flaw. This

becomes even more pronounced

when plotting flaws using an anglebeam; often the flaws plot into the

base metal when they shouldnt, or

they dont plot to the exact sameposition from each side of the

weld when they should. The

diagram on the right shows the

transducer dimensioning the flawsvia the 50% amplitude drop. The

flaw on the left gets oversized

because its smaller than the beamprofile. The flaw on the left is

accurately sized because its

dimension is larger than the beamprofile.

Flaw dimensionElement dimension

Figure 2. Cross Pattern to Achieve Full Volumetric Weld Examination

Flaws

50% drop50% drop50% drop50% drop

Figure 3. Flaw Dimensioning, 6dB Drop Method

In addition, it is recognized that other techniques different than the nominal 45o, 60

o& 70

oshear

wave examinations may be required verify and dimension planar flaws. This is a good reason

why codes specify a scanning sensitivity that is above the reference level. Flaw

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characterization and sizing methods such as ID Creeping Waves, Tip Diffraction, Bi-Modal, and

Refracted Longitudinal Waves have demonstrated a higher degree of accuracy for sizing thedepth of planar flaws in pipe, plate and vessel components welds, in lieu of the Amplitude

Comparison or dB Drop Techniques. Tip Diffraction is the only advanced technique discussed

in this curriculum.

Interpreting Signals

Rise and Fall Time

The signal rise time is related to how fast the signal peaks as the transducer is moved toward

a reflector, and how fast it falls when the transducer is moved away from it. As shownbelow, the rise and fall time of signals is drastically affected by the angle of the sound beam.

In the above diagram the beam profile is dimensioned instead of the SDH. This can lead to

over sizing flaws as well as underestimating flaw depth. This problem alleviates itself once

the flaw size is equal to or larger then the beam profile. Discontinuities with a through wall

dimension greater than the beam profile dimension will have a longer rise/fall time and bemore accurately dimensioned. Geometry

indications from a weld cap or weld root

exhibit a slow rise/fall time and have abroad base signal with multiple peaks.

70o

45o60o

Figure 4. A-Scan Displays of Rise/Fall Time Related to Angles

Peaks

Sound that is reflected back to the

transducer at different or varying time of

flight (TOF) indicates a multifacetedreflector surface and creates multiple peaks

on the signal. In most cases the

multifaceted surface is also irregular to Figure 5. Multiple Peaks From Irregular Surface

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Tip Diffracted

The radial wave pattern that emanates from a long crack tip is reliably detectable only in thefar field and requires a good signal to noise ratio. Better results obtained with a highly

damped 45o

or 60o

shear wave. Interpretation of RF A-scan display better for low amplitudesignals.

.

Fi ure 7. Ti Diffraction

These signals are important, due to their vertical orientation these types of planar indications aredifficult to detect. The technician needs to acknowledge their critical nature and further

investigate with other angles.

Transmit Receive

Figure 8. Transmit/Receive Technique

This signal only appears when it reflects from

a planar flaw and is received on a secondtransducer. A transmit/receive technique canbe employed to further investigate a planar

discontinuity. Through transmission is an

amplitude attenuation test.

Characterizing Indications in Welds

Root Indications (surface connected)

1. Root Geometry (irrelevant indication):

The operator should determine if the weld exhibits a root geometry that will reflect soundback to the transducer. The sound path should calculate to a thickness equal to or slightly

greater than weld plate thickness. The surface distance from each side of the weld should

not plot exactly to the same point or to the weld centerline. This signal should be closely

interpreted during inspection, so that other root indications coming up just in front of, oron the front flank of this signal, may be noted and interpreted also.

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Angle Beam General


Figure 9. Root Geometry

SD plot overlaps

Depth slightly greater thanPlate Thickness

2. Excessive Root:

Excessive Root is similar to the Root Geometry noted in Figure 9 above. Excessive rootbead will have sharper sides due to excess weld metal melting through. Signals will varymore in amplitude and exhibit a greater TOF than normal root geometry.

3. Longitudinal Crack (weld metal or HAZ):

Best detected with a 45o

angle due to corner trap at ID. Signal will appear sharp with fastrise time. The 60

oangle will provide approximately the return amplitude of the 45

o

angle. If the crack follows grain boundaries and exhibits a multifaceted face the signal

may exhibit a multiple peak and return less sound than a notch in a reference block.Crack indications should plot to same point from each side of weld.

SD plots to same point above crack

Figure 10. Longitudinal Crack in HAZ, Surface Connected

4. Transverse Crack (weld metal or HAZ):

Transducer needs to be aligned parallel to weld direction and skewed 30o

to propagate

sound in towards the weld root to detect short transverse root cracks. The skewed soundbeam will cause some sound to reflect off small transverse cracks and away from

transducer, reducing the returned amplitude.


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Ground Weld Cap

Weld CapFigure 11. Rotation of transducer for detection of transverse flaws.

5. Lack of Fusion (LOF):

Lack of fusion connected to ID at root face is difficult to distinguish from a longitudinalroot crack. If the depth of the LOF exceeds the root land and follows the angle of the

bevel it will return less sound from the side that is not at normal incidence to the sound

beam.6. Incomplete Penetration (IP):

A tight root fit up during welding, or poor arc penetration, can make this indication

difficult to distinguish from a centerline root crack. Signal characteristics from IP shouldexhibit a single peak because the sound beam is reflecting from a uniform surface.

Surface distance will not plot to exact same point. Depth

will be equal to or less than plate thickness.

Figure 12. Incomplete Penetration

7. Root Concavity (Suck Back):

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Suck Back will plot similar to incomplete penetration. Due to the concaved (rounded)

geometry of suck back the signal may not be as sharp, nor have as much amplitue, as thatof a centerline root crack or incomplete penetration.

Midwall Indications (subsurface)1. Lack of fusion on bevel face:

The sound beam needs to strike lack of fusion at or near normal incidence, therefore lackof fusion exhibits greater amplitude on the 2

ndleg when scanning from same side of weld

as indication, or 1st

leg when on opposite side of weld; unless weld thickness is great

enough the weld cap usually creates an obstacle and the 3rd

leg is required when on theopposite side of the weld joint. A 60

oangle is best suited for LOF on a 30

oweld joint

bevel and a 70o

angle is best suited for LOF on a 22.5o

weld joint bevel because they are

nearest the normal incidence of 90o.

Second leg on opposite side

of weld reflects off LOF

Second leg used to detect

LOF on same side

Figure 13. Lack of Fusion (LOF)

A slag line can generally be detected from both sides of the weld. Signal characteristicsmay include multiple peaks and a broad base.

2. Porosity

Porosity is generally difficult to detect. Signal characteristics may include multiple

peaks. Peaks can be maintained while skewing transducer.

3. Crack (weld metal or HAZ)

The midwall crack is one of the most difficult indications to detect. Generally speaking,

a vertical orientation of a planar flaw is best detected with a 70o

angle. See Figures 7 & 8for alternative techniques for characterizing a midwall crack.

Weld Cap Indications (surface connected)

1. Weld Cap GeometryThe operator should determine if the weld exhibits a weld cap geometry that will reflect

sound back to the transducer. This is a broad based signal with multiple peaks and is

generally maintained over full length of weld. Adjust amplitude to reference level andtry dampening signal with finger. The sound path should calculate to a full V path or

slightly greater. The surface distance should plot to the opposite side of weld cap. This

signal should be closely interpreted during examination, so that other indications comingup just in front of, or on the front flank of this signal, may be noted and interpreted also.

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2. Longitudinal Cracks (weld metal or HAZ)

Longitudinal Cracks are best detected at the end of the 2nd leg of the 45o

angle. Shallowtoe cracks are easy to miss when weld cap geometry exists.

3. Transverse Cracks (weld metal or HAZ)

Transducer needs to be aligned parallel to weld direction. The end of the second leg of a45

oangle is best suited for this indication.

Interpretation Tips for Non-relevant and False Indications

Refracted L-wave Indications

An angle beam shear wave soundbeam can impinge on an irregular surface creating arefracted L-wave that may travel straight up to the test piece surface, such as a weld cap, and

reflect back reconverting back to a shear wave and creating a irrevelant indication on the

screen that may be misinterpreted. If the operator wipes or dampens the surface area at Vpath SD the signal will dampen out if it is a refracted L-wave. Small diameter transducers

with large beam beam spreads and 60o angles are vulnerable to this non relevant inidication.

Creeper Wave Indications

The "so-called" creeping wave is putatively formed as a result of a simple compression wave

interacting at a free boundary. Upon incidence from a Lucite wedge designed to provide arefracted angle somewhere between about 70-80 degrees in a test piece, the "creeping wave"

forms on the near surface. This can easily occur when propagating sound circumferentially

around a radius surface, such as a pipe, using a non-radius transducer wedge. Place a finger

or pencil eraser right in front of transducer wedge to dampen this non-relevant signal out.The creeping wave attenuates out in about a inch of surface distance.

Figure 15. Creeper Wave Indication

Standing Wave Indications

More sound reflects inside a 70o

wedge than a 60o

or 45o

wedge, making the 70o

vulnerable

to this indication. When couplant builds up on the front of the wedge a mid screen standingsignal with a large signal base may appear on the CRT display. This signal is created by the

reflected and refracted sound inside the wedge and stays at the same TOF on the baseline.

Wiping the excess couplant off the end of the wedge will eliminate this false indication.

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Pre Inspection RequirementsIt is recommended that these pre inspection requirements be performed prior to calibrating

equipment and examining welds. The results of these measurements may be used to select

the best angle or determine a better technique.

Physical Measurements

1. Measure Weld Thickness (adjacent plate).2. Measure weld cap width.

3. Measure transducer offset (distance from sound exit point to front of wedge).

4. Add 2 and 3 above, this is the closest surface distance to the weld centerline thetransducer can be positioned.

Calculate Distances

1. Sound Path (SP) for 1

st

leg or V path.2. Surface Distance (SD) for 1st

leg or path.

3. If SD for V path is less than number 4 above then you CANNOT reach the weld rooton the first leg SP with the angle being used, you will have to use the third leg to get root

coverage or change to a higher angle.

4. Surface Distance (SD) for full V path.5. Surface Distance (SD) for 1 V path.

Mark Surface Distances on Plate Adjacent to Weld

1. Parallel to the weld mark a 1st

leg X line on the plate that is equal to a V Surface

Distance from the weld centerline; when the transducer exit point is on this line the end

of the 1

st

leg of Sound Path will be at the weld root.2. Parallel to the weld mark a 2nd

leg X line on the plate that is equal to a Full V Surface

Distance from the weld centerline; when the transducer exit point is on this line the end

of the 2nd

leg of Sound Path will be at the centerline of the weld cap.

3. Parallel to the weld mark a 3rd

leg X line on the plate that is equal to a 1 V SurfaceDistance from the weld centerline; when the transducer exit point is on this line the end

of the 1st

leg of Sound Path will be at the weld root.

Weld Profile/Sound Path Transparency

The Weld Profile/Sound Path Transparency is a useful tool to help the operator visualize

sound paths within a complex weld joint and to easily and quickly characterize a flaw; it also

serves as a useful tool to diagram to welders or clients where rejects or other discontinuitiesare located.

1. Using graph paper draw a cross section of the weld joint.

If weld thickness is much less than one inch the weld joint should be drawn on a 2:1scale.

Mark the weld centerline and in each direction mark reticules at about 0.2increments with cumulative distance at major reticules. Reference drawings or use

other means to obtain correct bevel angle(s) of weld joints.

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Make sure enough base plate exists to support the number of V paths you will usewhen examining the weld.

2. On a different graph paper draw, to the same scale, the sound path at the angle(s) and Vpaths to be used in examining the weld.

3. Mark the sound path distance at the end of each leg, then mark reticules along each sound

path leg at about 0.2 increments.4. Copy the weld cross section onto a transparency. You can now take the sound paths and

slide them through the weld to easily visualize weld joint location and surface distance to

discontinuities.

Basic Angle Beam CalibrationThese are just basic guidelines, each code will have specific tasks that must be performed.

Sweep Distance:

1. Use a miniature angle beam lock, DSC block or IIW block to calibrate sweep.2. Find main bang and position at left of screen.

3. Adjust screen range and or velocity to see the first reflections from a minimum of two

radiuses.4. Adjust gate to read leading edge of first reflector.

5. Adjust zero until sound path reads correctly from first radius.

6. Adjust gate to read leading edge of second reflector.7. Adjust velocity until sound path reads correctly from second radius

8. Repeat 4 7 until both signals read the correct sound paths.

Sensitivity

1. Find a sensitivity reflector (the right one depends on the code youre using) and adjustthis signal to 80% FSH. This is the reference level, or the amplitude level to which youwill adjust indication signals to record their information.

2. Verify this is correct signal by physically measuring depth and surface distance to

sensitivity reflector.

3. Check the horizontal sweep calibration after you adjusted the gain to the sensitivity level.4. Add from 6 to 20 dB to the reference level for detection purposes during scanning.

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APPENDIX A: AWS D1.1

Please see attached file UT AWS.pdf for current material.

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APPENDIX B: ASME V

Please see attached file UT ASME.pdf for current material.

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Quiz Questions:NAME:_________________________________________

1. To obtain full volume weld metal examination on a .580 thickness which of thefollowing scenarios is the most appropriate; i.e., provides the cross pattern with the least

amount of sound path?

a. A 1st

leg 70o

exam from both sides of the weldb. A 2

ndand 3

rdleg 45

oexam from both sides of the weld

c. A 3rd

and 4th

leg 60o

exam from both sides of the weld

d. A 2nd

and 3rd

leg 52o

exam from both sides of the weld.2. What is the surface distance in 1. a. above?

a. 1.96

b. .62

c. 2.0d. none of the above

3. A beam profile larger than the reflector may dimension the reflector as being

a. Oversizedb. Undersized

c. Correct size

d. +/-.10%4. The amplitude reflected from a crack should be

a. Equal to lack of fusion of similar size

b. Less than when sound is reflected at less than normal incidence

c. Maximum when sound is reflected at normal incidenced. Equal to the incident angle amplitude

5. What is the near field length of a .375 diameter, 7.5 MHz transducer propagating a

longitudinal wave mode in steel?(show your work)

6. If doing an ASME weld examination on an in-service pressure vessel dimensioning

indications for evaluation to acceptance standards to ASME VIII App 12.1 which Articlewould apply?

7. If performing an ASME 24 schedule 40 pipe weld examination, which article would

apply?

8. Which code allows the use of dual transducers?

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9. Which code requires a horizontal linearity procedure?

10. Which Article(s) require Amplitude Control and Screen Height Linearities?

11. What ASME Article section describes the beam spread measurement?

12. What is the best transducer selection for an AWS job?a. .25 diameter, 5MHz

b. .50 diameter, 2.25 MHz

c. 1 diameter 2.5 MHz

d. b & c above

13. When examining a 3 butt weld on a building to AWS which of the following is

correcta. A 45

oand 60

oangle are required

b. A 60o

angle to the middle half and 45o

angle for the bottom quarter

c. A 70o, with the weld cap ground flush

d. A 45o

and 70o

e. c & d above

14. In question 13, the following information has been tabulated: reference level 28,

indication level 40, examination angle 70o and reflector at 8 sound path. What is theindication rating?

a. A

b. Bc. C

d. D

15. The indication for question 13 is 2.25 inches in length, is ita. Acceptable

b. Rejectable

16. What is the scanning sensitivity for question 13?a. 20

b. 25c. 19

d. none of the above

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17. What frequency is most appropriate for an AWS examination?

a. 7.5 MHz

b. 10.0 MHzc. 5 MHz

d. 2.5Mhz

18. When calibrating to AWS, what is the diameter of the sensitivity reflector in the IIWblock?

a. .60

b. .060 mmc. 60 mm

d. .060

19. What is the transducer position(s) (its a letter) for verifying a wedge angle on an IIWblock?

a. A

b. Kc. C

d. F

e. B

20. What part of AWS would you reference to develop a technique for a material < 5/16?

Angle Beam General


86511176 ultrasonic testing in accordance with aws d1 5 asme v

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