Questions Flashcards
(98 cards)
1
Q
Sound waves continue to travel until:
a. they are redirected by material surfaces.
b. they are completely dissipated by the effects of beam divergence.
c. they are transformed into another waveform.
d. all of the energy is converted into positive and negative ions.
A
a. they are redirected by material surfaces.
2
Q
- Wavelength may be defined as:
a. frequency divided by velocity.
b. the distance along a wavetrain from peak to trough.
c. the distance from one point to the next identical point along the waveform.
d. the distance along a wavetrain from an area of high particle motion to one of low particle motion.
A
c. the distance from one point to the next identical point along the waveform.
3
Q
- To determine wavelength:
a. multiply velocity by frequency.
b. divide velocity by frequency.
c. divide frequency by velocity.
d. multiply frequency by wavelength.
A
b. divide velocity by frequency.
4
Q
- The wavelength of a 5 MHz sound wave in water is [VL = 1.483(10)5 cm/s]:
a. 0.297 mm (0.012 in.).
b. 2.54 mm (0.10 in.).
c. 296 mm (11.65 in.).
d. 3.00 mm (0.12 in.).
A
a. 0.297 mm (0.012 in.).
5
Q
- Thickness resonance occurs when transducers and test parts are excited at a frequency equal to
(where V = sound velocity and T = item thickness):
a. 2T/V.
b. T/2V.
c. V/2T.
d. 2V/T.
A
c. V/2T.
6
Q
- The equations that show VL and VT being dependent on elastic properties suggest that:
a. materials with higher densities will usually have higher acoustic velocities.
b. materials with higher moduli will usually have higher velocities.
c. wave velocities rely mostly upon the ratios of elastic moduli to material density.
d. VT will always be one-half of VL in the same material.
A
c. wave velocities rely mostly upon the ratios of elastic moduli to material density.
7
Q
- Velocity measurements in a material revealed that the velocity decreased as frequency increased. This material
is called:
a. dissipated.
b. discontinuous.
c. dispersive.
d. degenerative.
A
c. dispersive.
8
Q
- Plate thickness = 25.4 mm (1 in.), pulse-echo straight beam measured elapsed time = 8 µs. What is the most
likely material?
a. carbon steel.
b. lead.
c. titanium.
d. aluminum.
A
d. aluminum.
9
Q
- The acoustic energy reflected at a plastic glass-quartz interface is equal to:
a. 64%.
b. 41%.
c. 22%.
d. 52%.
A
b. 41%.
10
Q
- It can be deduced from Table 2 that the densities of:
a. plastic glass and water are in the ratio of 1.17:1.
b. steel and aluminum are in the ratio of 2.31:1.
c. quartz and aluminum are in the ratio of 1.05:1.
d. water and quartz are in the ratio of 10.13:1.
A
a. plastic glass and water are in the ratio of 1.17:1.
11
Q
- The acoustic energy transmitted through a plastic glass-water interface is equal to:
a. 87%.
b. 36%.
c. 13%.
d. 64%
A
a. 87%.
12
Q
- The first critical angle at a water-steel interface will be:
a. 18°.
b. 14.5°.
c. 22°.
d. 35°.
A
b. 14.5°.
13
Q
- The second critical angle at a water-aluminum interface will be:
a. 28°.
b. 33°.
c. 67°.
d. 90°.
A
a. 28°.
14
Q
- The incident angle needed in immersion testing to develop a 70° shear wave in plastic glass using the
information in Table 2 equals:
a. 83°.
b. 77°.
c. 74°.
d. 65°
A
b. 77°.
15
Q
- Figure 2 shows the partition of incident and transmitted waves at a water-aluminum interface. At an
incident angle of 20°, the reflected wave and transmitted waves are respectively:
a. 60% and 40%.
b. 40% and 60%.
c. 1/3 and 2/3.
d. 80% and 20%.
A
a. 60% and 40%.
16
Q
- From Figure 2 it is evident that the sum of the incident wave’s partitions (transmitted and reflected) is:
a. highly irregular at low angles, but constant above 30°.
b. lower at angles between 16° and 26°.
c. rarely more than 0.8.
d. always equal to unity.
A
d. always equal to unity.
17
Q
- The principal attenuation modes are:
a. absorption, scatter, beam spread.
b. beam spread, collimation, scatter.
c. scatter, absorption, focusing.
d. scatter, beam spread, adhesion.
A
a. absorption, scatter, beam spread.
18
Q
- Attenuation caused by scattering:
a. increases with increased frequency and grain size.
b. decreases with increased frequency and grain size.
c. increases with higher frequency and decreases with larger grain size.
d. decreases with higher frequency and decreases with larger grain size.
A
a. increases with increased frequency and grain size.
19
Q
- In very fine-grain, isotropic crystalline material, the principal loss mechanism at 2 MHz is:
a. scatter.
b. mechanical hysteresis.
c. beam spread.
d. absorption.
A
c. beam spread.
20
Q
- Two plates yield different backwall reflections in pulse-echo testing (18 dB) with their only apparent
difference being in the second material’s void content. The plates are both 75 mm (3 in.) thick. What is the
effective change in acoustic attenuation between the first and second plate based on actual metal path distance?
a. 0.118 dB/mm (3 dB/in.)
b. 0.236 dB/mm (6 dB/in.)
c. 0.709 dB/mm (18 dB/in.)
d. 0.039 dB/mm (1 dB/in.)
A
a. 0.118 dB/mm (3 dB/in.)
21
Q
- The equation, sin ϕ = 0.7 λ/D, describes:
a. beam spread angle at 50% decrease in signal from the centerline value.
b. one-half the beam spread angle at 50% decrease in signal from the centerline value.
c. one-half the beam spread angle at 20% decrease in signal from the centerline value.
d. one-half the beam spread angle at 100% decrease in signal from the centerline value.
A
b. one-half the beam spread angle at 50% decrease in signal from the centerline value.
22
Q
- The beam spread half-angle in the far field of a 25.4 mm (1 in.) diameter transducer sending 5 MHz longitudinal
waves into a plastic glass block is:
a. 0.5°.
b. 1.5°.
c. 3.1°.
d. 6.2°.
A
b. 1.5°.
23
Q
- The near field of a round 12.7 mm (0.5 in.) diameter contact L-wave transducer being used on a steel test
part operating at 3 MHz is:
a. 12.7 mm (0.5 in.).
b. 25.4 mm (1 in.).
c. 9.9 mm (0.39 in.).
d. 20 mm (0.79 in.).
A
d. 20 mm (0.79 in.).
24
Q
- The depth of penetration of the sound beam into a material can be increased by:
a. using a higher frequency.
b. using a longer wavelength.
c. using a smaller transducer.
d. using a lower frequency and a larger transducer.
A
d. using a lower frequency and a larger transducer.
25
1. Barium titanate is a piezoelectric material which:
a. occurs naturally.
b. is piezoelectric at temperatures above the critical temperature.
c. has a high acoustic impedance.
d. is highly soluble in water.
c. has a high acoustic impedance.
26
2. During an immersion test, numerous bubbles are noted in the water attached to the test item. These bubbles are small relative to the part size. What steps should the operator take?
a. Remove the bubbles by blowing them off with an air hose.
b. Ignore the bubbles because they are small and will not interfere with the test.
c. Remove the bubbles, with a brush or other mechanical means such as rubbing with the hand while the test is stopped.
d. Count the bubbles and mark their echoes on the test record.
c. Remove the bubbles, with a brush or other mechanical means such as rubbing with the hand while the test is stopped.
27
3. A couplant is needed for a test on a hot steel plate (121 °C, 250 °F). Which of the following materials can be used?
a. water.
b. mercury.
c. tractor oil.
d. high-temperature grease.
d. high-temperature grease.
28
4. A couplant is needed for a test on stainless steel welds. Numerous couplants are available. Which should be chosen and why?
a. a couplant free of chlorine because this element corrodes stainless steel.
b. glycerin because it is nonflammable.
c. oil because it is easily removed.
d. water because stainless steel does not corrode in water.
a. a couplant free of chlorine because this element corrodes stainless steel.
29
5. A 5 MHz, 12.7 mm (0.5 in.) diameter, flat search unit in water has a near field length of approximately:
a. 177.8 mm (7 in.).
b. 50.8 mm (2 in.).
c. 84.6 mm (3-1/3 in.).
d. 139.7 mm (5-1/2 in.).
d. 139.7 mm (5-1/2 in.).
30
6. A concave lens on a transducer will result in the near field in water being:
a. twice as long as with a flat lens.
b. three times as long as with a flat lens.
c. the same length as with a flat lens.
d. shorter than with a flat lens.
d. shorter than with a flat lens.
31
7. A 10 MHz, 12.7 mm (0.5 in.) diameter search unit is placed on steel and acrylic plastic in succession. The
beam spread in these two materials is approximately:
a. 3° and 1.5°, respectively.
b. 1.5° and 3°, respectively.
c. equal in the two materials.
d. less than the beam spread of a 15 MHz search unit of the same diameter.
a. 3° and 1.5°, respectively.
32
8. Focused transducers are useful because the:
a. smaller beam diameter increases the number of scans required to examine an object.
b. lateral resolution is improved.
c. lateral resolution is unimportant.
d. focal point is located beyond the end of the near field length of a similar, unfocused transducer.
b. lateral resolution is improved.
33
9. Which of the following is a true statement about a sound beam with a longer wavelength.
a. A longer wavelength has better penetration than a shorter wavelength.
b. A longer wavelength provides a greater sensitivity and resolution.
c. A longer wavelength has less energy than a shorter wavelength.
d. Wavelength does not affect penetration, resolution or sensitivity.
a. A longer wavelength has better penetration than a shorter wavelength.
34
10. Backing material on a transducer is used to:
a. damp the pulse and absorb the sound from the back of the transducer.
b. decrease the thickness oscillations.
c. increase the radial mode oscillations.
d. increase the power of the transmitted pulse.
a. damp the pulse and absorb the sound from the back of the transducer.
35
11. Angle beam search units are used to:
a. inspect butt joint welds in thick-wall steel piping.
b. inspect pipe walls for internal corrosion.
c. examine material for acoustic velocity changes.
d. determine acoustic diffraction.
a. inspect butt joint welds in thick-wall steel piping.
36
12. An angle beam transducer produces a 45° shear wave in steel. What is the approximate incident angle?
(velocity in steel = 0.125 in./µs, velocity in plastic = 0.105 in./µs; velocity in steel = 3.175 mm/µs,
velocity in plastic = 2.667 mm/µs)
a. 54.9°
b. 19°
c. 36.4°
d. 45°
c. 36.4°
37
13. In Figure 6, the aluminum rod being examined is 152.4 mm (6 in.) in diameter. What is the offset
distance needed for a 45° refracted shear wave to be generated?
[L-wave velocity in aluminum = 6.3 (10)6 mm/s, T-wave velocity in aluminum = 3.1 (10)6 mm/s,
velocity in water = 1.5 (10)6 mm/s]
a. 5.13 mm (0.2 in.)
b. 26.06 mm (1.026 in.)
c. 52.12 mm (2.052 in.)
d. 15.05 mm (0.59 in.)
b. 26.06 mm (1.026 in.)
38
14. In Figure 6 and using the conditions of question 13, what is the offset distance needed for a 45° refracted
longitudinal wave to be generated?
a. 10.03 mm (0.395 in.)
b. 4.5 mm (0.177 in.)
c. 12.82 mm (0.505 in.)
d. 10.26 mm (0.404 in.)
c. 12.82 mm (0.505 in.)
39
15. It is desired to detect discontinuities 6.35 mm (0.25 in.) or less from the entry surface using angle beam shear waves. The search unit must be selected with the choice between a narrow band and a broadband unit. Which should be chosen and why?
a. The narrow band unit because it examines only a narrow band of the material.
b. The broadband unit because the entire volume is examined with a long pulse.
c. The broadband unit because the near surface resolution is better.
d. The broadband unit because the lateral resolution is excellent.
c. The broadband unit because the near surface resolution is better.
40
16. In a longitudinal-wave immersion test of commercially pure titanium plate
[VL = 6.1 (10)6 mm/s, VT = 3.12 (10)6 mm/s], an echo pulse from an internal discontinuity is observed
6.56 µs following the front surface echo. How deep is the reflector below the front surface?
a. 20 mm (0.79 in.)
b. 40 mm (1.57 in.)
c. 10 mm (0.39 in.)
d. 50.8 mm (2 in.)
a. 20 mm (0.79 in.)
41
17. A change in echo amplitude from 20% of full screen height (FSH) to 40% FSH is a change of:
a. 20 dB.
b. 6 dB.
c. 14 dB.
d. 50% in signal amplitude.
b. 6 dB.
42
18. What lens radius of curvature is needed in order to have a 20 mm diameter, 5 MHz transducer focus in
water at a distance of 40 mm from the lens face? [VH2O =1.49 (10)6 mm/s, VLens = 2.67 (10)6 mm/s]
a. 17.7 mm (0.7 in.)
b. 35.0 mm (1.38 in.)
c. 80.5 mm (3.17 in.)
d. 56.6 mm (2.23 in.)
a. 17.7 mm (0.7 in.)
43
19. Two signals were compared in amplitude to each other. The second was found to be 14 dB less than
the first. This change could have represented a change of:
a. 70% FSH to 14% FSH.
b. 100% FSH to 50% FSH.
c. 20% FSH to 100% FSH.
d. 100% FSH to 25% FSH.
a. 70% FSH to 14% FSH.
44
20. A change of 16 dB on the attenuator corresponds to an amplitude ratio of:
a. 6.3:1.
b. 5.2:1.
c. 7.4:1.
d. 9.5:1.
a. 6.3:1.
45
21. When checked against a previous calibration level, a search unit which is classified as highly damped is
considerably more sensitive. A check of the RF waveform shows that the unit rings for at least three times the number of cycles previously achieved. What condition might explain this phenomena?
a. The search unit has been dropped and the facing material has been cracked.
b. The backing material has separated from the crystal, thus decreasing the mechanical damping.
c. The housing has separated from the transducer and thinks it is a bell.
d. The coax connector is filled with water.
b. The backing material has separated from the crystal, thus decreasing the mechanical damping.
46
22. The sound beam emanating from a continuous wave sound source has two zones. These are called the:
a. fresnel and fraunhofer zones.
b. fresnel and near fields.
c. fraunhofer and far fields.
d. focused and unfocused zones.
a. fresnel and fraunhofer zones.
47
1. Calibration is the term used to:
a. describe the means to measure the diameter of a shaft.
b. set up the test item for examination in accordance with rules established by the NIST (formerly the NBS).
c. describe the means to establish the working characteristics of a search unit.
d. describe the process of establishing the gain level and the sweep distance of the UT instrument.
d. describe the process of establishing the gain level and the sweep distance of the UT instrument.
48
2. An area-amplitude block has the designation 4340-4-0500. This indicates that it is:
a. an aluminum block with a #3 hole at a depth of 125 mm (5 in.).
b. a steel block with a 1.5 mm (1/16 in.) hole at a depth of 125 mm (5 in.).
c. a steel block with a #5 hole at a depth of 101.6 mm (4 in.).
d. a titanium block with a #4 hole at a depth of 125 mm (5 in.).
b. a steel block with a 1.5 mm (1/16 in.) hole at a depth of 125 mm (5 in.).
49
3. The term sweep distance is used to describe:
a. how fast the sound is able pass through the material.
b. the equivalent sound beam path displayed on the display in terms of unit distances in the test material.
c. the velocity with which the search unit is moved across the material.
d. how electrical energy passes from the transducer to material being tested.
b. the equivalent sound beam path displayed on the display in terms of unit distances in the test material.
50
4. A calibrated display screen is necessary for measurement of:
a. signal amplitudes to determine distances to the reflectors.
b. electric currents generated by the piezoelectric crystal.
c. distances from the beginning to the end of the scan path.
d. distance along the sound path to establish thickness or reflector location.
d. distance along the sound path to establish thickness or reflector location.
51
5. A reflector signal was found to be 6 dB lessthan that from the calibration reflector at the same sound path. The calibration reflector was a No. 8 FBH. What can be said about the unknown reflector? It is:
a. 1.6 mm (4/64 in.) diameter.
b. 3.2 mm (8/64 in.) diameter.
c. probably 3.2 mm (8/64 in.) diameter or larger.
d. an unknown size.
d. an unknown size.
52
6. In Figure 6, the response from the 3.25 mm FBH at a depth of 25.4 mm is above that detected from the 1 mm FBH by:
a. 24.0 dB.
b. 18.2 dB.
c. 12.0 dB.
d. 10.8 dB.
d. 10.8 dB.
53
7. The half-angle beam spread of the reflected wave front from a #8 FBH in an aluminum “A” block being immersion tested using a 25 MHz transducer is:
[VL = 1.5 (water); VL-Al = 6.3; VT-Al = 3.1; ... all velocities (10)6 mm/s].
a. 1.30°.
b. 5.47°.
c. 22.77°.
d. 48.50°.
b. 5.47°.
54
8. A DAC curve is to be established using the SDHs in the block as shown in Figure 9.
Three points have been established: 1/8, 2/8 and 3/8 nodes from 1/4, 1/2 and 3/4 T SDHs.
What would be the next point?
a. 4/8 node.
b. 5/8 node.
c. 6/8 node.
d. 8/8 node.
b. 5/8 node.
55
9. Which of the following is an advantage of side-drilled hole reflectors for calibration?
a. They can be placed at essentially any distance from the entry surface.
b. The surface of the hole is rough, providing a strong, specular reflection.
c. The hole depth is limited to 3 times the diameter.
d. The hole diameter can be used directly and easily to measure the size of an unknown reflector.
a. They can be placed at essentially any distance from the entry surface.
56
10. When measuring the angle on an angle beam search unit using an IIW block, two signals are noted. The first measures at an angle of 49° and the second peaks at an angle that is estimated to be 25°. Using the information
below, identify the signals. Longitudinal wave velocity in plastic = 2.76 mm/µs;
Longitudinal wave velocity in steel = 5.85 mm/µs; Shear wave velocity in steel = 3.2 mm/µs.
a. First is shear, second is longitudinal.
b. First is longitudinal, second is surface.
c. First is longitudinal, second is love wave.
d. First is longitudinal, second is shear.
d. First is longitudinal, second is shear.
57
11. When using a focused, straight beam search unit for lamination scanning in an immersion test of a steel plate, a change in water path of 5 mm (0.2 in.) will result in the focal point moving in the steel a distance of:
a. 5 mm (0.2 in.).
b. 0.2 mm. (0.008 in.).
c. 1.27 mm (0.05 in.).
d. 20.3 mm (0.8 in.).
c. 1.27 mm (0.05 in.).
58
12. A search unit with a focal length in water of 101.6 mm (4 in.) is used. A steel plate, 203 mm (8 in.) thick, velocity = 0.230 in./ms, is placed at a water path of 50.8 mm (2 in.) from the search unit. At what depth is the focal point in the steel?
a. 25.4 mm (1 in.).
b. 50.8 mm (2 in.).
c. 12.7 mm (0.5 in.).
d. 20.3 mm (0.8 in.).
c. 12.7 mm (0.5 in.).
59
13. During an examination, an indication of 25% FSH is detected and maximized. For better analysis, the gain is increased by 12 dB and the indication increases to 88% FSH. What value should have been reached and what is
the apparent problem?
a. 50% FSH and the screen is nonlinear.
b. 75% FSH and there is no problem.
c. 100% FSH and the sweep speed is nonlinear.
d. 100% FSH and the screen is nonlinear.
d. 100% FSH and the screen is nonlinear.
60
14. The difference between through-transmission and pitch-catch techniques is that:
a. the transducers in through-transmission face each other, while in pitch-catch the transducers are often side by side in the same housing.
b. the transducers in through-transmission are side by side, while in pitch-catch the transducers are facing each other.
c. the transducers in through-transmission are always angle beam.
d. in through-transmission the depth of the discontinuity is easily determined.
a. the transducers in through-transmission face each other, while in pitch-catch the transducers are often side by side in the same housing.
61
15. In the tandem technique, a signal is received from the test material. The reflector may be located:
a. near the front surface.
b. at the back surface.
c. somewhere near midwall.
d. by any of the above, depending on the material thickness, the refracted angle, the distance between search units and the distance between the transducer and the reflector.
c. somewhere near midwall.
62
16. In a tandem 70° pitch-catch shear wave arrangement, the plate being inspected is 50.8 mm (2 in.) thick and the region of interest is midway between top and bottom surfaces. How far behind the transmitter should the receiving transducer be located?
a. 17.3 mm (0.68 in.).
b. 47.8 mm (1.88 in.).
c. 101.6 mm (4.00 in.).
d. 139.7 mm (5.50 in.).
d. 139.7 mm (5.50 in.).
63
17. Angle beam search units are frequently used in weld testing. One reason for this is that the angle beam:
a. is more sensitive to slag and porosity.
b. is more sensitive to inadequate penetration and cracks.
c. does not attenuate as it traverses the material.
d. provides multiple back-surface echoes for thickness testing
b. is more sensitive to inadequate penetration and cracks.
64
18. An automated examination of a large cylinder is to be performed using a focused search unit [focal point = 1.27 mm (0.050 in.) diameter, focal length = 50.8 mm (2 in.), and crystal diameter = 12.7 mm (0.500 in.)]. To ensure 10% overlap between scans, of the following, what increment should be used?
a. 0.127 mm (0.005 in.).
b. 12.573 mm (0.495 in.).
c. 1.016 mm (0.040 in.).
d. 1.257 mm (0.0495 in.).
c. 1.016 mm (0.040 in.).
65
19. While performing a straight-beam, immersion test, an indication is noted lying midwall. What immediate action should the operator take?
a. Report it to his/her supervisor.
b. Check to ensure that the search unit to part distance is correct.
c. Replace the component within another identical one to see if the same indication exists in the second unit.
d. Check to ensure the refracted angle is 45°.
b. Check to ensure that the search unit to part distance is correct.
66
20. The reflected pulse reaching the immersion transducer from the back surface of a
114. 3 mm (4.5 in.) aluminum plate standing in a tank of water is equal to ______ of the energy pulse which was transmitted from the transducer. (Zal = 17, ZH2O = 1.5)
a. 6.22%
b. 70.2%
c. 50.7%
d. 14.7%
a. 6.22%
67
21. A pair of squirters each with a 228.6 mm (9 in.) water stream are used in the examination of a large panel in the through-transmission mode. The search units are arranged in a horizontal position. It is desired to locate discontinuities within 0.254 mm (0.010 in.) of their true position. The analyst should take which of the following actions?
a. Assume that the coordinates given by the scanning system are correct and use those values for the coordinates.
b. Determine the curve of the water stream due to the influence of gravity and adjust the coordinate values to compensate for the deflection.
c. Overlay the test record on the part and mark the reflector locations.
d. Precisely measure from the index point on the panel to the indicated location and mark the part.
b. Determine the curve of the water stream due to the influence of gravity and adjust the coordinate values to compensate for the deflection.
68
22. In preparing a scanning plan (the set of directions describing the performance of an ultrasonic examination), which of the following parameters should be considered, as a minimum?
a. Sound beam diameter, refracted angle, beam direction, gate settings, starting point for the first scan, number of scans.
b. Sound beam diameter, refracted angle, operator’s name, gate settings, starting point, number of scans.
c. Sound beam diameter, refracted angle, beam direction, expected flaws, instrument serial number.
d. Sound beam far field length, refracted angle, beam direction, gate settings, starting point, number of scans.
a. Sound beam diameter, refracted angle, beam direction, gate settings, starting point for the first scan, number of scans.
69
23. A 76.2 mm (3 in.) thick flat plate of polystyrene during immersion testing exhibits an echo from the back surface of the plate that is ______ of that received from the front surface. (Both sides immersed in water, ZPoly = 2.7, ZH2O = 1.5.)
a. 8.4%
b. 84.00%
c. 8.16%
d. 6.88%
b. 84.00%
70
24. A major problem in the use of search unit wheels is:
a. insufficient traction leading to skidding and bad wrecks.
b. elimination of undesirable internal echoes.
c. installing adequate brakes.
d. selecting a rigid tire material
b. elimination of undesirable internal echoes.
71
25. A scanning plan is a document which:
a. outlines the various steps in preparing a procedure.
b. defines the most efficient way to analyze
the data.
c. gives the detailed steps entailed in examining the test item.
d. gives the complete history of previous examinations.
c. gives the detailed steps entailed in examining the test item.
72
26. In contact testing, the back surface signal from a 50.8 mm (2 in.) plate was set at full screen height. Passing over a coarse grained area, the back surface signal dropped to 10% of the full scale signal. What would be your estimate of the change in attenuation in this local area based on actual metal path distance?
a. 0.787 dB/mm (20 dB/in.).
b. 0.393 dB/mm (10 dB/in.).
c. 0.196 dB/mm (5 dB/in.).
d. 10%/in.
c. 0.196 dB/mm (5 dB/in.).
73
1. In a through-transmission, immersion examination of an adhesively bonded lap joint, the signal is noted to decrease in amplitude in a small area of less than 1.59 mm (1/16 in.) diameter as recorded on a C-scan.
What condition might cause this indication?
a. A bubble on the surface of the joint or a spot in the joint that is not bonded.
b. The joint is tightly bonded in this area.
c. There is nothing that could cause this condition—it is an anomaly.
d. The adhesive has melted in this area causing an increase in sound transmission.
a. A bubble on the surface of the joint or a spot in the joint that is not bonded.
74
2 Advantages of computer controlled ultrasonic testing include:
a. lower capital equipment costs.
b. high dependence of the test results on the capability of the operator.
c. real-time analysis of test results.
d. no need for instrument calibration even though such action is required by the specification.
c. real-time analysis of test results.
75
3 During the test of a fiberglass-epoxy composite, numerous echoes are recorded in the pulse-echo mode. What action should be taken?
a. The part should be rejected because all echoes are from discontinuities.
b. The part should be rejected because the supervisor was not there to give advice.
c. The part should be accepted because all composites will have numerous echoes.
d. The procedure should be consulted to determine the analysis technique and the accept/reject criteria.
d. The procedure should be consulted to determine the analysis technique and the accept/reject criteria.
76
4 An immersion, pulse-echo test is performed on a thin adhesively bonded joint between a composite material and an aluminum substrate. The sound beam enters the joint normally and from the composite side. The amplitude gate is set on the interface between the composite and the aluminum.
If the joint is not bonded, the signal should:
a. decrease, because water has a lower velocity than the aluminum.
b. decrease, because water in the area that is not bonded will conduct sound better than air.
c. increase, because air in the area that is not bonded will reflect more sound energy than the aluminum.
d. increase, because the composite will resonate.
c. increase, because air in the area that is not bonded will reflect more sound energy than the aluminum.
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5 Three major sources of noise which interfere with the signals on the display are:
a. front surface roughness, hydraulic motors and enlarged grain structure.
b. back surface roughness, electric motors and decreased grain structure.
c. depth, size and location of a discontinuitiy.
d. front surface roughness, arc welding operations and enlarged grain structure.
d. front surface roughness, arc welding operations and enlarged grain structure.
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6 A single V butt weld in a 76.2 mm (3 in.) plate is being examined using a 60° shear wave. An indication on the display appears at a sound path distance of 228.6 mm (9 in.). At the same time, the exit point of the transducer is 198.12 mm (7.8 in.) from the centerline of the weld. This suggests the
reflector could be:
a. a crack in the near side HAZ.
b. lack of fusion at the weld/base material interface.
c. a slag inclusion in the center of the weld.
d. an undercut condition on the far side of the weld.
c. a slag inclusion in the center of the weld.
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7 Under the conditions in question 6, but with the indication at a 152.4 mm (6 in.) sound path distance and with the exit point 132.08 mm (5.2 in.) from the weld centerline, another strong indication is received indicating a probable reflector in the:
a. root area of the weld.
b. crown area of the weld.
c. midsection of the weld.
d. base metal adjacent to the weld.
a. root area of the weld.
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8 Under the conditions in question 6, but with the indication at a sound path distance of 228.6 mm (9 in.) and with the exit point 205.74 mm (8.1 in.) from the weld centerline, the reflector lies in a plane that is ______ from the center of the weld.
a. 2.54 mm (0.1 in.) on the far side
b. 7.62 mm (0.3 in.) on the near side
c. 7.62 mm (0.3 in.) on the far side
d. 12.7 mm (0.5 in.) on the near side
b. 7.62 mm (0.3 in.) on the near side
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9 Under the conditions in question 6, the reflector is at a depth of ______ (measured from the transducer side).
a. 38 mm (1.5 in.)
b. 25.4 mm (1.0 in.)
c. 50.8 mm (2.0 in.)
d. 57.1 mm (2.25 in.)
a. 38 mm (1.5 in.)
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10 In a thick-walled piping weld inspection, the counter-bore on the ID reflects the incident 45° shear wave so that it strikes the top surface (outer diameter) at normal incidence. In order for this to happen, the taper on the counter bore must be: (See Figure 7.)
a. 30°.
b. 45°.
c. 11.25°.
d. 22.5°.
d. 22.5°.
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11 Under the above conditions, an L-wave is internally mode converted at an angle with the sin β given by:
a. sin β = (VL/VS) sin (incident angle).
b. sin β = (VL/VS) sin 45°.
c. sin β = (VS/VL) sin 90°.
d. sin β = 4 sin (incident angle).
a. sin β = (VL/VS) sin (incident angle).
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12 A pipe being examined automatically using immersion techniques (with mode conversion to a 45° shear wave at the pipe wall-water interface) is experiencing a wobbling displacement (transverse to the pipe axis) of ±10% of its nominal offset value. The corresponding change in inspection angle would be:
a. +11, –14%.
b. +13, –12%.
c. +10, –10%.
d. +14, –10%.
b. +13, –12%.
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13 During production testing, a rod is passing under a transducer in a stuffing box (immersion testing).
What is the expression that relates pulse repetition rates (PRR) of the UT instrument with the surface speed (Vp) of the test part, given a transducer of width D?
a. D = Vp/PRR
b. PRR = D × Vp
c. Vp = D/PRR
d. Vp = D × PRR
a. D = Vp/PRR
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14 An inspection specification calls for three hits of an echo in order for a discontinuity to be considered valid and for the alarm to sound. The maximum axial speed of test part movement is therefore _______ for a 1 in. (25.4 mm) diameter transducer (assume no beam spread) and a PRR of 600 pulses per second (PPS).
a. 45 720 mm/s (1800 in./s)
b. 15 240 mm/s (600 in./s)
c. 7 620 mm/s (300 in./s)
d. 5 080 mm/s (200 in./s)
d. 5 080 mm/s (200 in./s)
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15 A butt weld in a 38 mm (1.5 in.) thick plate is to be examined from both sides using a 70° shear wave.
The scan program calls for being able to inspect three egs (1.5 V-paths). Weld access for completing this pattern will require how much surface distance, plus the physical dimensions of the transducer assembly?
a. 114.3 mm (4.50 in.).
b. 209.3 mm (8.24 in.).
c. 313.94 mm (12.36 in.).
d. 628.14 mm (24.73 in.).
c. 313.94 mm (12.36 in.).
88
16 The discontinuity detector’s sound path sweep setting on a 10-division graticle display for the above case should be:
a. 33.53 mm/div. (1.32 in./div.).
b. 25.4 mm/div. (1.00 in./div.).
c. 31.75 mm/div. (1.25 in./div.).
d. 12.7 mm/div. (0.50 in./div.).
a. 33.53 mm/div. (1.32 in./div.).
89
17 A 3.05 m (10 ft) long turbine shaft is to be inspected from one end with 0°, longitudinal wave for radial,
circumferential fatigue cracks in an area between 2286 mm (90 in.) and 2794 mm (110 in.) from the inspection end. The available instrument screen can display a maximum of 2032 mm (80 in.). How should the operator proceed?
a. Inspect using a 2032 mm (80 in.) screen and file an exception report.
b. Set up 508 mm (20 in.) screen and delay the start to 2286 mm (90 in.).
c. Set up a 2032 mm (80 in.) screen and delay the start to 762 mm (30 in.).
d. Assume there are no cracks and turn in a report.
b. Set up 508 mm (20 in.) screen and delay the start to 2286 mm (90 in.).
90
18 A 0° axial test is being performed on a steel railroad axle 2.4 m (8 ft) long and 152.4 mm (6 in.) in diameter. A strong but unsteady signal is seen near the center of the display screen. A similar signal is seen from the other end of the axle. The following conditions are given:
Screen distance: 3 048 mm (304.8 mm/div.) [10 ft (12 in./div.)]
Damping: minimum
Gain: 85 dB
Pulse repetition rate: 2000 pulses per second
Frequency: 2 MHz, range: 1270 mm (50 in.)
Reject: off, Filter: off
Sweep speed: as required
Sweep delay: as required
What action should the operator take?
a. Record the indication and notify the supervisor.
b. Change the PRR to 1000 pulses per second and observe the effect.
c. Compare the signal to the reference standard and reject the axle if the reference level is exceeded.
d. Determine if the signal responds to finger damping by touching the opposite end.
b. Change the PRR to 1000 pulses per second and observe the effect.
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1. Additional company requirements would most likely be found in which of the following documents?
a. A code.
b. A standard.
c. A specification.
d. An inspection procedure.
c. A specification
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2. Which type of document would contain specific information on equipment selection and scanning area?
a. A code.
b. A standard.
c. A specification.
d. An inspection procedure
d. An inspection procedure
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3. Which of the following personnel are required to work to specific written instructions?
a. Trainees.
b. Level I.
c. Level II.
d. Both Level I and Level II.
b. Level I.
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4. Which of the following organizations writes the majority of NDT performance standards?
a. ASTM.
b. ASME.
c. AWS.
d. ANSI.
a. ASTM.
95
```
5. Inspection procedures are usually based on which of
the following documents?
a. A work instruction.
b. A standard.
c. A specification.
d. A regulatory requirement.
```
b. A standard.
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6. What system of development is used in the U.S. to develop standards?
a. Free market.
b. Government oversight.
c. For-profit industry.
d. Regulatory agencies.
a. Free market.
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7. Which of the following organizations is responsible for issuing commissions to Authorized Inspectors,
Authorized Nuclear Inspectors and Authorized Nuclear In-service Inspectors?
a. ASTM International.
b. The American Society of Mechanical Engineers.
c. The National Board of Boiler and Pressure Vessel Inspectors.
d. The American National Standards Institute.
c. The National Board of Boiler and Pressure Vessel Inspectors.
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8. Which document would a person use to learn about the requirements for a pressurized heat exchanger?
a. The AWS D1.2 Welding Code.
b. API 650.
c. ASTM E-2375.
d. The ASME BPV, Section VIII
d. The ASME BPV, Section VIII
