ana
snswers
A
Levels I, I1 and I11
Magnetic Particle Testing
Method
Supplement to
Recommended Practice
NO. SNT-TC-1A
Book B - second edition
The American Society
for Nondestructive Testing, Inc.
wer
I
Levels I, I1 and I11
Magnetic Particle Testing
Method
Supplement to
Recommended Practice
NO. SNT-TC-IA
Book B - second edition
The American Society
for Nondestructive Testing, Inc.
The questions in this book were originally compiled by the Magnetic Particle Supplement Committee of the
Personnel Qualification Division, Education and Qualification Council of the American Society for Nondestructive
Testing. This edition was updated and edited by Charles W. Eick, Dassault Falcon Jet.
Published by
The American Society for Nondestructive Testing, Inc
1711 Arlingate Lane
PO Box 285 18
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Copyright O 2M)7 by The American Society for Nondestructive Testing, Inc. ASNT is not responsible for the
authenticity or accuracy of information herein. Products or services that are advertised or mentioned do not carry
the endorsement or recommendation of ASNT.
This publication contains suggested questions and answers in the Magnetic Particle Testing Method for use in conjunction with Recommended Practice No. SNT-TC-IAfor Personnel Qualification and Certification in
Nondestructive Testing. Recommended Practice No. SNT-TC-1A is available from ASNT.
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ISBN-13: 978-1-57117-147-4
Printed in the United States of America
first printing 07/87
second printing 03/88
third printing 04/88
fourth printing OY89
l i f i printing 04/90
sixth printing 05/92
seventh printing with revision 05/94
eighth printing 10/96
ninth printing 11/98
10th printing 07/03
11th printing 03/06
Second edition
first printing 03/07
Table of Contents
Recommended 'Ikaining References
Reference Usage List
Level I
Questions
Answers
Level I1
Questions
Answers
Level 111
Questions
Answers
Recommended lkaining References
h~
Magnetic Particle ~ e s t Method
The following references were used in formulating the questions contained in this book.
A,* Betz, Carl E. Principles of Magnetic Particle Testing. Chicago, IL; Magnatlux Corporation.
2004.
B. ASTM E 1444, Sfandard Practice for Magnefic Particle Eramination, West Conshohocken,
PA, ASTM International. Current edition.
C.* Schmidt, Thomas J., Kermit Skeie, tech. eds.; Paul McIntire, ed. Nondesfructive Testing
Handbook, second edition: Volume Six, Magnetic Particle Testing, Columbus, OH, The
American Society for Nondestructive Testing, Inc. 1989.
D. McMaster, R.C., ed. Nondesfructive Testing Handbook, fyst edition. Columbus, OH, The
American Society for Nondestructive Testing, Inc. 1959.
E.* Eick Chuck W. Level 11Study Guide: Magnetic Particle Testing Mefhod, second edition,
Columbus, OH; The American Society for Nondestructive Testing, Inc. 2003.
F.* Fenton, John D. ASNTLevel 111Study Guide: Magnetic Pamkle TesfingMefhod, second
edition, Columbus, OH, The American Society for Nondestructive Testing, Inc. 2006.
G.* Magnetic Particle Testing Classmorn Training Book. Columbus, OH, The American Society
for Nondestructive Testing, Inc. 2004.
Each question found in this book is followed by letter@) and page number(?.) indicating the
specific recommended reference where the answer may be found. For example:
27.
A metal that is difficult to magnetize is said to have:
a.
b.
c.
d.
high permeability.
low permeability.
high reluctance.
low retentivity.
Ref: C.45
In this example, the letter "C"refen to Reference C in the list above and "45" is the specific
page in Reference C where the answer to the question is located.
Reference Usage List
Reference A: Total = 65
Level I(10)
Level II (32)
Level III (23)
Reference B: Total = 0
Level I (0)
Level I1 (0)
Level III (0)
Reference C: Total = 161
Level I (74)
Level I1 (45)
Level III (42)
Reference D: Total = 1
Level I (0)
Level I1 (1)
Level III (0)
Reference E: Total = 7
Level I (4)
Level U (3)
Level III(0)
Reference F: Total = 0
Level I(0)
Level I1 (0)
Level 111(0)
Reference G: Total = 4
Level I(4)
Level I1 (0)
Level I11 (0)
Magnetic Particle Testing M e t m Level I
Level I Questions
Magnetic Particle Testing Method
1.
Magnetic particle is a nondeshuctive testing
method used for:
5.
a locating surface and near surface
discontinuities in aluminum.
b. locating surface and near surface
discontinuities in steel.
c. finding and measuring material separation.
d. measuring flux density.
Ref: C.2
2.
Magnetic particles are available in different
colors:
a. for color contrast with the part surface thereby
enhancing detection of indications.
b. to enhance the detection of indications by
allowing background color matching.
c. to determine if an indication is surface or
subsurface.
d. to indicate different magnetic flux values.
Ref: C.36
Ferromagnetic material is:
6.
a.
b.
c.
d.
strongly attracted by a magnet.
not highly saturated by magnetic fields.
a material with a 0 permeability measnrement.
not capable of being magnetized.
Ref: C.24
Which of the following can be magnetized?
a.
b.
c.
d.
iron
copper
aluminum
magnesium
Ref: C.24
3.
The permeability of a material demibes:
7. The magnetic field is strongest when:
a
b.
c.
d.
4.
the ease with which it can be magnetized.
the depth of the magnetic field in the part.
the lengtb of time required to demagnetize it.
the ability to retain the magnetic field.
Ref: C.26
a.
b.
c.
d.
the magnetizing voltage is flowing.
the magnetizing current is flowing.
the material exhibits high coercive forces.
the magnetizing current is not flowing.
Ref: C.24
The retentivity of a material describes:
8.
a.
b.
c.
d.
the ease with which it can be magnetized.
the depth of the magnetic field in the part.
the length of time required to demagnetize it.
the ability to retain the magnetic field.
Ref: C.24
If a crack exists in a circular magnet, the
attraction of magnetic particles to the crack is
caused by:
a.
b.
c.
d.
a coercive force.
a leakage field.
a Doppler effect.
a high reluctance at the crack.
Ref: 12.15
Magnetic Particle Testing Method, Level I
9.
The unit usually used to denote flux density is:
a.
b.
c.
d.
gauss.
henry.
farad.
ampere.
Ref: C.24
10. Which statement is true when related to magnetic
lines of force?
a. They are often forced to cross due to part
geometry.
b. They are most dense at the poles of a magnet
c. They seek the path of most resistance.
d. They cannot be detected.
Ref: C12
14. The magnitude of the residual magnetic field in a
specimen is dependent on:
a
b.
c.
d.
the length-to-diameter ratio (IfD).
the strength of the applied magnetizing force.
the right-hand rule.
the left-hand rule.
Ref: C.24
15. The proper number of a m p - h u n s for a given
test specimen being examined by longitudinal
magnetism is determined by:
a its length and diameter.
b. the material.
c. the diameter and the material.
d. its diameter.
Ref: A. 182
11. Magnetic flux Lines that are parallel to a
discontinuity produce:
a.
b.
c.
d.
16. A circular field may be induced into a specimen
by:
strong indications.
weak indications.
no indications.
fuzzy indications.
Ref: C.16
12. A part is adaptable to magnetic particle
inspection if:
a.
b.
c.
d.
a.
b.
c.
d.
placing the part in an energized coil.
passing current directly through the part.
passing a magnetic field through the part.
placing the part in a north-south orientation.
Ref: C.150
17. An elechicakyoke produces:
it is attached to an elech.ostatic field.
the material is ferromagnetic.
the material is non-ferrous.
the material is an electric conductor.
a
b.
c.
d.
a longitudinal field.
a circular field.
alternating fields.
a swinging field.
Ref: C.24
13. What rule describes the d i i t i o n of current flow
(+ to -) when lines of magnetic force s n ~ ~ ~ an n d
conductor?
a.
b.
c.
d.
left-hand rule
right-band rule
flux rule
reluctance rule
Ref: C.22
18. An energized coil around the part produces:
a
b.
c.
d.
a circular field.
a longitudinal field.
an intermittent field.
a field dependent on the type of current
applied.
Ref: C.152
Ref: C.19
19. In longitudinal magnetization the proper tern for
calculating magnetizing force is:
a.
b:
c.
d.
amperes.
a m p nuns.
watts.
ohms.
Ref: A.182
Magnetic Particle Testing Method, Level Z
20. Magnetic lines of force:
a
h.
c.
d.
travel in straight lines.
form a closed loop.
are randomly oriented.
overlay in highly ferromagnetic materials.
Ref: C.12
25. The flux within and surrounding a magnetized
part or around a conductor camying a current is
known as:
a.
b.
c.
d.
the saturation point.
a magnetic field.
the ferromagnetic field.
the paramagnetic field.
Ref: C.12
21. A magnetic particle buildup from a discontinuity
is smngest when the discontinuity is oriented:
a.
b.
c.
d.
180 degrees to the magnetic flux flow.
45 degrees to the magnetic flux flow.
90 degrees to the magnetic flux flow.
90 degrees to the current flow.
Ref: C.297
26. The areas on a magnetized part from which the
magnetic field is leaving or returning into the
part are called:
a salient points.
b. defects.
c. magnetic poles.
d. nodes.
Ref: C.12
22. A specimen may be demagnetized by which of
the following methods?
a Heat treatment below the curie temperature.
b. Placing the part in an alternating current coil.
c. Placing the part in reversing and decreasing
direct current fields.
d. Applying a direct current yoke and removing
it from the part.
Ref: A.66
27. A metal that is difficult to magnetize is said to
have:
a.
b.
c.
d.
high permeability.
low permeability.
high reluctance.
low retentivity.
Ref: C.45
23. Which of the following is an advantage of
magnetic particle testing over peneh'ant testing?
a It does not require post-cleaning of the part.
b. It reauires direct access to the surface of the
Part.
c. It can detect near-surface discontinuities.
d. It requires h shorter dweU time to pmduce
results.
Ref: A.66
24. The amount of amperage used for magnetic
particle inspection using the prod method is
determined from the:
a.
b.
c.
d.
28. The magnetism that remains in a piece of
magnetizable material after the magnetizing force
has been removed is called the:
a.
b.
c.
d.
Ref: C.25
29. Subsurface discontinuity indications usually
appear:
a.
b.
c.
d.
type of material.
distance between the prods.
diameter of the part.
total length of the part.
tramp magnetism.
residual magnetism.
damped magnetism.
permanent magnetism.
sharp and distinct.
sharp and wide.
wide and fuzzy.
high and loosely held.
Ref: E.35
Ref: C.151
Magnet* Particle Testing Method, Level I
35. A curve is sometimes drawn to show graphically
the relation of the magnetizing force to the
strength of the magnetic field produced in a
certain material. This curve is !mown as the:
30. Which residual field is most difficult to
demagnetize?
a.
b.
c.
d.
longitudinal
circular
vector
binodal
Ref: C.33
a. magnetic force curve.
b. hysteresis curve.
C. saturation curve.
d. induction curve.
Ref: C.24
31. Which magnetic particle application technique is
the most sensitive?
36. What method of applying particles provides
greater sensitivity in locating subsurface weld
discontinuities?
a. continuous
h. residual
c. interrupted
d. counter-current
Ref: C.38
a.
b.
c.
d.
Ref: C.207
32. Fluorescent magnetic particle indications should
be inspected under:
a.
b.
c.
d.
37. When magnetizing a weld in two directions, and
if the current used in the f m t direction is 750 A
and the current in the second direction is 400 A,
which of the following is true?
any light.
a neon light.
an ultraviolet light.
a fluorescent light.
Ref: C.37
33. Inspecting a part by magnetizing, removing the
current flow, then applying the medium is called
the:
a.
b.
c.
d.
continuous
residual
circular
longitudinal
continuous method.
wet method.
residual method.
dry method.
Ref: C.37
34. Which of the following is the most effective
method for the detection of subsurface defects?
a. Dry residual method using DC with surge.
b. Wet continuous method using half-wave
rectitied current.
c. Wet residual method.
d. Dry continuous method using half-wave
rectified current with prods.
Ref: C.207
a. The part should be checked to see if
demagnetization between operations is
necessary.
b. No precautions should be taken before the
second operation.
c. This is not a valid technique.
d. There is no need to magnetize a weld in two
dictions.
Ref: C.30
38. When there is absolutely no pattern or
distribution of magnetic particles on the part, the
possible cause is that:
a.
b.
c.
d.
the amperage setting is too high.
the amperage setting is too low.
the particle bath strength is too high.
the part is made of high retentivity steel.
Ref: A.64
Magnetic Particle Testing M e t h d Level I
39. What are three causes of nonrelevant indications?
a. lack of fusion, change of section thickness,
grinding cracks
b. change of section thichess, heat affected
zones, drilled hole near surface
c. very high amperage, drilled hole near surface,
blow holes
d. drilled hole near surface, very high amperage,
lack of fusion
Ref: C.234
40. Using the residual test method, a number of parts
are magnetized and laid on a rack prior to
application of magnetic particles. Why is it
important that they do not rub or touch each
other?
a.
b.
c.
d.
There is a possible loss of the magnetic field.
It may cause magnetic writing.
It may damage the part.
It makes parts hard to handle.
Ref: C.234
41. The point at which the magnetism in a material
cannot be increased even though the magnetizing
force continues to increase is known as the:
44. Residual magnetic particle inspection may be
used when:
a. parts are irregular in shape.
b. parts are highly retentive.
c. parts are highly stressed.
d. evaluating continuous method indications.
Ref: C.37
45. Magnetic particle inspection is & a reliable
method of detecting:
a. laps.
b. deep internal cavities.
c. cracks.
d. seams.
Ref: C.233
46. The wet fluorescent magnetic particle inspection
method is the same as the visible wet magnetic
particle method except that the fluorescent
magnetic particle inspection method requires:
a.
b.
c.
d.
an ultraviolet light.
a higher current.
a different machine.
alternating current.
Ref: C.37
a.
b.
c.
d.
salient pole.
saturation point.
residual point.
remnant point.
47. A discontinuityopen to the surface produces an
indication which is:
RekC.24
42. Which type of current produces a skin effect on
the surface of the part?
a. sharp and distinct.
b. wide and indefinite
c. crisscrossed.
d. high and fuzzy.
Ref: E.35
a.
b.
c.
d.
alternating current
d i i c t current
half-wave rectified
full-wave rectified
48. Which of the following will produce circular
magnetism?
Ref: C.27
43. When using the wet method, why should a high
velocity flow of wet method bath over surfaces
following removal of the magnetizing current not
be used?
a. It may wash away a fme or weakly held
indication.
b. This is not a problem.
c. It may splash particles into eyes.
d. None of the above is correct.
Ref: E.23
a.
b.
c.
d.
passing current through a coil
placing the test part in a solenoid
yokes
passing current through prods
Ref: G.ll
Magnetic P h l e Testing M e t h d Level I
49. When using the wet continuous method, the flow
of suspension from the hose should be shut off:
a.
b.
c.
d.
55. P m s should be cleaned after demagnetization:
a. to ensure that the magnetic particles are
removed.
b. to prevent false indications.
c. to Have the solids of the suspension.
d. to prevent cracking during heat treatment.
Ref: C.30
immediately after applying the current.
immediately before applying the current.
while the current is flowing.
30 seconds before applying the current.
Ref: G.52
50. The strongest magnetic field in a coil is at the:
56. In circular magnetization, the magnetizing force
is expressed in amperes. What term is used tn
express magnetizing force in longitudinal
magnetization?
a. outside edge.
b. inside edge.
C. center.
d. end.
a.
b,
c.
d.
Ref: G.17
amperes
ampere-turns
consequent poles
volts
Ref: E.18
51. To detect lengthwise discontinuities on the inside
diameter of hollow parts, you should:
a.
b.
c.
d.
pass current thmugh it.
magnetize with a coil.
pass current through a central conductor.
increase the amperage used.
Ref: C.152
57. A longitudinal surface crack in a circularly
magnetized part will cause:
a.
b.
c.
d.
the magnetic field to die out.
a decrease in permeability.
a magnetic leakage field.
a current to flow.
Ref: C.18
52. What equipment is used to determine if a part
has been demagnetized?
a.
b.
c.
d.
a magnet on the paIT
a field meter
a survey meter
careful observation for clinging magnetic
particles
Ref: C.302
58. In a magnetic particle test, assuming that all of
the following are in the same relative position in
a small part, which would be the hardest to
detect?
a.
b.
c.
d.
53. Which of the following is most often used for
dry magnetic particle inspection?
a.
b.
c.
d.
Ref: A.62
full cycle & i t current
half-wave rectified alternating current
high voltage, low amperage current
& i t current from electrolytic cells
Ref: C.202
59. If wet magnetic particle suspension is gpt
uniform, then:
a. the strength of an indication may vary, and the
interpretation of the indication may be
erroneous.
h. the magnetic flux would not be uniform.
c. greater mobility would be required.
d. the part cannot be magnetized.
Ref: A.261
54. An electric current through a copper wire:
a.
b.
c.
d.
a surface crack
a near surface crack
a scratch
a seam
creates a magnetic field around the wire,
creates magnetic poles in the wire.
magnetizes the wire.
does not create a magnetic field.
Ref: C.18
6
Magnetic Particle Testing M e t h d Level I
60. Which of the following currents will best define
surface cracks?
a.
b.
c.
d.
half-wave rectified alternating current
direct current
alternating current
surge current
Ref: A.232
65. When magnetic material is placed into a coil, the
magnetic lines of flux concentrate themselves in
the material and:
a.
h.
c.
d.
create a longitudinal magnetic field.
create a circular magnetic field.
create a longitudinal circular field.
have no effect.
Ref: C.19
61. When a magnetic field is induced in a part with
prods spaced 152 mm (6 in.) apart, the field is:
a.
b.
c.
d.
solenoidal.
circular.
longitudmal.
distorted trapezoidal.
Ref: C.23
66. Which form of magnetization is easiest to detect
in most parts?
a.
b.
c.
d.
longitudinal magnetization
permanent magnetism
circular magnetization
parallel magnetization
Ref: C.293-294
62. Applying the theory of the right-hand rule, a
longitudinal surface defect in a round bar is
detected by "current passing in a d i c t i o n
parallel to the direction of expected defects"
because:
a. the current direction is in line with the defect.
b. the magnetic field is at right angles to the
defect.
c. it makes no difference.
d. the magnetic field is parallel to the defect.
Ref: C.19 and 150
67. The best type of magnetic field to use to inspect
a tubular product for surface defects along its
length is a:
a.
b.
c.
d.
longitudinal field.
circular field.
swinging field.
yoke magnetization.
Ref: C.150
68. The area of maximum induced field strength
using a yoke is:
63. If a current is passed through an electrical
conductor, what will surround the conductor?
a.
b.
c.
d.
eddy current field
current
magnetic field
residual field
a.
b.
c.
d.
at the north pole of the yoke.
at the south pole of the yoke.
the area directly between the poles.
on the outside of pole pieces.
Ref: C.23
Ref: C.18
64. With current flowing from + to -in a coil, a
longitudinal field is created. Which of the
following may be used to establish the d i i o n
of the magnetic field?
a.
b.
c.
d.
left-hand rule
right-hand rule
Ohm's law
Newton's law
69. The strength of the magnetic field induced in a
part is often referred to as:
a.
b.
c.
d.
current density
voltage.
flu density.
retentivity.
Ref: C.15
Ref: C.19
Magnetic Particle Testing Method, Level I
70. A major factor that determines the success of
magnetic particle inspection is the:
a.
b.
c.
d.
75. When using wet particles in water suspension,
wetting agents are added to:
a.
b.
c.
d.
field strength.
voltage on magnetizing coil.
current through the coil.
time of magnetization.
Ref: C.15-16
71. What type of current is best suited to detect
surface discontinuities?
a.
b.
c.
d.
direct current
alternating current
pulsating direct current
half wave.
Ref: C.27
prevent freezing.
prevent corrosion of inspection equipment
ensure the proper wetting of the part.
decrease the amount of water needed.
Ref: C.208
76. When preparing an inspection bath, the amount
of magnetic particles per gallon of fluid is called
its:
a.
b.
c.
d.
measuring scale.
particle number.
strength or concentration.
usable limits.
Ref: G.100-101
72. When preparing a magnetic particle bath, it is
important to have the bath strengtb at a proper
level, as ton many particles can result in:
a.
b.
c.
d.
lowering the test amperage.
having to increase the magnetizing current.
masking the indications.
none of the above.
Ref: C.210
73. One advantage of using fluorescent particles is:
a.
b.
c.
d.
that less equipment is required.
the high speed of inspection.
the cost.
that they are more readily attracted than other
particles.
Ref: A.275-276
74. When using a dry magnetic particle powder, the
proper way to apply it to the part is to:
a
b.
c.
d.
forcibly apply it with air.
roll the material in the container of powder.
apply it from the bottom of the part.
float the particles to inspection surface as
gently as possible.
Ref: C.36
77. Coercive force:
a. describes the means by which the magnetic
particles are suspended in the liquid when
using the wet method.
b. describes the magnetizing force used with the
continuous method.
c. represents the reverse magnetizing force
necessary to remove the residual magnetism in
a material.
d. is not a term used in magnetic particle testing.
Ref: C.24
78. Demagnetization:
a. may be accomplished by heating a material
above its curie point.
b. is always necessary.
c. can be performed only with alternating
current.
d. can be performed only with direct current.
Ref: C.292-293
79. Resistance to demagnetization:
a.
b.
c.
d.
is greater in hard materials than soft materials.
is greater in soft materials than hard materials.
is the same for both hard and soft materials.
is nonexistent.
Ref: C.295
Magnetic Particle Testing Method, Level I
85. Which of the following statements is a
disadvantage of magnetic particle testing?
80. Demagnetization:
a. may be easy or difficult depending on the type
of material.
b. is easy for materials having a high coercive
force.
c. is always most difficult in materials retaining
a high residual field.
d. AU of the above answers are correct.
Ref: C.295
81. The strength of the wet suspension should be
maintained at a given level because:
a.
b.
c.
d.
a low level may give weak indications.
a high level may give heavy background.
both A and B.
none of the above.
Ref: C.209
a. It can be used only on ferrous materials.
h. It can be applied only to detect surface
defects.
c. It can be applied only to detect subsurface
defects.
d. It can be applied to detect surface and
subsurface discontinuities in ferrous material.
Ref: A.66-68. C.2
86. Which one of following magnetic particles will
be most sensitive to small surface discontinuities
such as fatigue cracks?
a.
b.
c.
d.
dry powder
fluorescent particle
visible particle using oil as carrier (vehicle)
visible particle using water as carrier (vehicle)
Ref: C.211
82. Indications such as those at local external poles,
sharp fillets or thread roots are called:
87. Magnetic particles should have the:
a.
b.
c.
d.
fake indications.
relevant indications.
nonrelevant indications.
magnetic writing indications.
Ref: C.234
83. Magnetic particle testing will reveal
discontinuities in which one of the followine
materials?
-
a.
b.
c.
d.
bronze
carbon steel
aluminum castings
austenitic stainless steel
Ref: C.2
84. Magnetic particle testing is a nondestmctive
testing method for detectine discontinuities in
magnetizable material. ThiHmethod can detect:
a.
b.
c.
d.
surface discontinuities only.
subsurface discontinuities only.
surface and subsurface discontinuities,
discontinuities at surface and subsurface of
any depth.
Ref: C.2
a.
b.
c.
d.
highest possible retentivity.
lowest possible permeability.
highest possible permeability.
highest possible permeability and lowest
possible retentivity.
Ref: C.34
88. Nonrelevant indications can be caused by the
following, except:
a.
b.
c.
d.
excessive magnetizing current.
inadequate magnetizing current.
structural design of the test specimen.
variance of permeability within the test
specimen.
Ref: C.293
89. A material with magnetic permeahility less than
1 is known as:
a.
b.
c.
d.
diamagnetic.
paramagnetic.
ferromagnetic.
panamagnetic.
Ref: C.13
Magnetie Particle Testing M e w Level I
90. A small device, generally a metal ship or disk,
containiug an artificial discontinuity used to
determine when the correct magnetizing
condition or magnetic field direction has been
achieved is:
a an ohmmeter.
b. a gauss meter.
c. a flux indicator.
d. a field indicator.
Ref: C.43
91. The direction of magnetic line of forcc is
-
degrees from the direction of current flow.
Ref: C.19
Magnetie Particle Testing Method, Level I
Level I Answers
Magnetic Particle Testing Method
Level I1 Questions
Magnetic Particle Testing Method
1.
The interpretation of magnetic particle
indications may be aided by:
5.
a. observing with a magnifying glass.
b. reproducing the indication after
demagnetization.
c. observing the indications after the part is
pre-cleaned.
d. observing the indications after the part is
post-cleaned.
Ref: C.235
2.
3.
a defect.
an indication.
a deformation.
a discontinuity.
Ref: C.43
Comparing parts that have been circularly
magnetized and those that have been
longitudinally magnetized, which retain the most
objectionable residual field if not demagnetized?
a.
b.
c.
d.
circular
vectored
remnant
longitudinal
Ref: A.313
circular
parallel
vectored
longitudinal
Ref: A. 182
6.
Why are large soft contact pads such as lead or
copper braid used for surfaces or headstocks?
a. To increase the contact area and reduce the
possibility of burning the part.
b. Because they help heat metal, thus facilitating
magnetic induction.
c. To increase the contact area and flux density.
d. Because of their low melting points.
Ref: C.42
in demagnetization.
in proper heat treating.
in the deposition of weld metal.
in interpretation and evaluation of indications.
Ref: A.397
An interruption in the normal physical structure
or configuration of a part which produces a
magnetic particle testing indication is called:
a.
b.
c.
d.
4.
a.
b.
c.
d.
Residual magnetism may be beneficial as an aid:
a.
b.
c.
d.
What type of magnetization uses the formula:
Ampere turns = 45 000/(IiD)?
7.
A rough forging that has received no further
processing is magnetic particle tested. An
indication is observed to run in every direction
and appears to extend deeply into the part and
perpendicular to the surface. It is very sharp.
What is the probable identity of the indication?
a.
b.
c.
d.
forging burst
flake
seam
lap
Ref: A.85-86
Magnetic Particle Testing Method, Level 11
8.
A gear with case-hardened ground teeth and hub
ends is magnetic particle tested. Individual
indications are detected on five teeth and one end
surface of the hub. The indications do not break
over the part edges. What is the probable identity
of the indication?
a grinding cracks
b. quench cracks
c. inclusions
d. porosity
9.
Ref: A.90-91
If an overall pattern (sometimes circular lines)
appears on the test surfaces, how should the
inspector reprocess the test piece?
a.
b.
c.
d.
Demagnetize the piece.
Retest at a higher amperage.
Retest at lower amperage.
Part is not testable.
Ref: A.383
10. A prime consideration when selecting a powder
to be used as a magnetic particle medium is to
select a powder that:
a. will adhere to the surface being tested.
b. provides a low contrast to the surface being
tested.
c. provides a high contrast to the surface being
tested.
d. q u i r e s a high demagnetization current to
remove it.
Ref: C.36
11. When testing for fine shallow surface cracks, the
preferred magnetic particle test method should
be:
a
b.
c.
d.
dry alternating current.
dry direct current.
wet alternating current.
wet direct current.
Ref: C.27.37
12. Which of the following is an advantage of the
dry method over the wet method?
a It is more sensitive to fine surface cracks.
b. It is easier to use for field inspection with
portable equipment.
c. It is faster than the wet method when testing a
number of small parts.
d. It is more capable of providing full surface
coverage on irregularly shaped patts.
Ref: C.37
13. When testing a bar with a length-tdameter
ratio of 4 in a 1 0 - m coil, the q u i d current
would be:
c. 1125A.
d. Unknown, more information is needed.
Ref: A.208
14. Internal splines and holes drilled parallel to, or
near, test surfaces will cause:
a. sharp, well-defined indications directly
aligned with the part's internal contours.
b. broad, fuzzy indications directly aligned with
the pan's internal contours.
c. distinct indications not aligned with any
internal contours.
d. no indications.
Ref: C.234
15. A limitation of coil magnetization techniques is
that:
a. regardless of part size, the part cannot be
painted.
b. the coil must be of maximum diameter in
relation to part.
c. the effective field is generally limited on
either side of the coil.
d. small diameter parts must be placed close to
the center of the coil.
Ref: A. 146
Magnetic Particle Testing M e t w Level I1
16. Which of the following wave patterns depicts the
wave form of three-phase full-wave mdtied
alternating current?
Ref: C.28
- +??
i
-e-,
;,,q-T-T-k
<xtT
h1 A
1p I q\ / ' \
\/
, /<\ ,
\ I,\ # 1 ,
17. Which of the following casting discontinuities is
caused by nonuniform cooling resulting in
stresses that rupture the surface of the metal?
a. hot teat's
h. porosity
c. dross
d. shrhkage
Ref: C.77
--
1
18. The term used to refer to the total opposition to
flow of current represented by the combined
effect of resistance, inductance and capacitance
of a circuit is:
1 cycle
a.
b.
c.
d.
inductive reactance.
imphnce.
reluctance.
decay.
Ref: A.122
19. A 3500 ampere-turn coil shot is required to be
performed in a 5-turn coil after a head shot of
800 A using the wet continuous method. In order
to properly conduct the coil shot it is necessary
to:
Tie
a. demagnetize the part between the head and
fmt coil shot.
b. check the part for residual magnetism with a
field indicator.
c. remove all residual wet magnetic particle fluid
from the part using clean, dry absorbent rags.
d. place the part in the coil and continue the
inspection after evaluating the head shot
indications.
Ref: A.308
20. When adding concentrate in paste form to any
wet magnetic particle suspension liquid, it is
common practice to:
a add the paste directly to the suspension liquid.
b. change the entire bath after thoroughly
cleaning the system.
c. make a small, sluny-lie test mixture of paste
and suspension and add d i i t l y to the bath.
d. mix paste in a small container with suspension
to the required bath strength and add directly
to the bath.
Ref: A.264
Magnetic Particle Testing M e t w Level ZZ
26. Forging laps occur in what relation to the axial
21. A desirable property of magnetic particles used
for either the dry or wet method is that they:
a.
b.
c.
d.
direction of a part?
a. They are always found on thermal centerline.
b. They are found on the surface of a part at a
90-degree angle to the long axis.
c. They may occur anywhere in the part and
always run in the direction of working.
d. They may occur anywhere on the surface and
may bear no relation to the axial k t i o n of
the part.
Ref: A.86
be toxic.
be nonfemmagnetic.
possess high retentivity.
possess high permeability.
Ref: C.201
22. Which of the following can cause nonrelevant
magnetic particle indications?
a. joints between dissimilar metals
b. thread cracks
c. scratches
d. bum
Ref: C.234-235
27. The accumulation of particles at a site on the part
surface, collected at and held to the site by the
magnetic leakage field, is called:
a.
b.
c.
d.
23. External poles which are too strong to pennit
good inspection of a part are more Likely to result
when using:
a.
b.
c.
d.
longitudinal magnetization.
polarized magnetization.
residual magnetization.
circular magnetization.
28. Where particles are attracted to a site on the
surface of a part by a magnetic leakage field that
is caused by a condition such as a crack, lap, or
other condition not acceptable to the applicable
standards for the pan, then we have:
a.
b.
c.
d.
24. A mugh forging discontinuity has the fouowing
characteristics: can occur on swface or internally,
is associated with low temperature processing, is
often caused by excessive working and creates
cavities varying in size. How would it be '
identified?
a defect.
an indication.
a discontinuity.
a nonrelevant indication.
Ref: E.33
pipe
burst
shrinkage
lamination
29. Half-wave rectified alternating current is used for
detection of:
a. surface defects only.
b. subsurface defects only.
c. surface and subsurface defects when using dry
particles.
d. surface and subsurface defects when using wet
particles.
Ref: C.155
Ref: C.83
25. Discontinuities in plate, sheet or strip caused by
internal fissures, inclusions or blowholes in the
original ingot which, after rolling, are usually flat
and parallel to the outside surface are called:
a.
b.
c.
d.
a discontinuity.
magnetic writing.
Ref: E.33
Ref: A.382
a.
b.
c.
d.
a defect.
an indication.
laps.
seams.
cracks.
laminations,
Ref: C.81
16
Magnetic Particle Testing Method, Level II
30. Which of the following is an acceptable
technique for removing a thin film of oil or
grease prior to magnetic particle testing?
a.
b.
c.
d.
Wash wim a solvent.
Degrease using a sand-blasting method.
Brush the surface with power wire brush.
Coat the surface with a thick layer of chalk
and then wipe with cloth.
Ref: A.246-247
31. Which of the following is the most common
method used for preserving and documenting
magnetic particle indications?
a
b.
c.
d.
35. Which of these cracks may appear as an
irregular,checked or scattered pattern of fine
lines usually caused by local overheating?
a.
b.
c.
d.
Ref: C.8
36. Of the following discontinuity categories, which
one is considered most detrimental to the service
life of an item?
a.
b.
c.
d.
photography
color-tinted tape
color-tinted lacquer
a concise word description
corrosion
crater cracks
fatigue cracks
grinding cracks
corrosion
subsurface inclusions
cracks open to the surface
subsurface porosity and voids
Ref: A.369-370
Ref: A.407-412
32. Which of the following is rn a discontinuity
common to rolled products?
a
b.
c.
d.
seams
cracks
cold shuts
laminations
Ref: D.77
33. Which one of the following is PPt a discontinuity
that can be produced by the forging process?
a.
b.
c.
d.
37. If a copper conductor is placed through a ferrous
cylinder and a current is passed through the
conductor, then the magnetic field (flux density)
in the cylinder will be:
a. less than in the conductor.
b. greater than in the conductor.
c. the same intensity and pattern as in the
conductor.
d. the same regardless of its proximity to the
cylinder wall.
Ref: A.192
38. The length of a part being magnetized by passing
an electric current from one end to the other:
laps
bursts
flakes
shrinkage
Ref: C.7
a.
b.
c.
d.
34. Which of the following is a discontinuity
commonly associated with the welding process?
a.
b.
c.
d.
flakes
seams
laminations
lack of penetration
Ref: C.7-8
causes the magnetic field to vary.
affects the permeability of the part.
changes the strength of the magnetic field.
does not affect the strength of the magnetic
field.
Ref: A.186
39. If 25 mm (I in.) and 51 mm (2 in.) diameter bars
of the same material were magnetized by passing
the same current through them, the magnetic
fields would be:
a.
b.
c.
d.
the same for both.
stronger in the 5 1 mm (2 in.) diameter bar.
weaker in the 25 mm (1 in.) diameter bar.
stronger in the 25 mm (1 in.) diameter bar.
Ref: A.189
Magnelic P&k
Testing Method, Level I1
40. If a current of the same amperage is passed
t h u h two conductors of the same dimensions,
one 07which is magnetic and one of which is
nonmagnetic, the magnetic field distribution
sunr&ding the conductors will:
a.
b.
c.
d.
vary with the permeability.
be the same for both conductors.
be stronger for the magnetic conductor.
be stronger for the nonmagnetic conductor.
Ref: A.189
44. When the most complete demagnetization
available is desired and demagnetization is to be
accomplished by placing the
in a coil
energized with alternating current of
pro&ssively decreasing-amperage, the following
orientation of the long axis of the part is most
desirable:
a
b.
c.
d.
east-west.
north-east.
south-west.
north-south.
ReE A.324
41. The most effective magnetic particle test method
for inspection of a large casting is using:
a.
b.
c.
d.
45. During a magnetic particle test, nonrelevant
indications due to residual local poles are noted
to be interfering with the magnetic particle
testing. For a successful examination one should:
a tend conductor.
direct magnetization.
multidirectional magnetization.
prod inspection in two directions.
a
b.
c.
d.
Ref: A.450
42. The most common failure mechanism associated
with in-service parts with sharp fillets, notches,
undercuts and seams is:
a.
b.
c.
d.
shrinkage.
crystallization.
deaxburization.
fatigue cracking.
use more amperage.
use lower amperage.
magnetize in another direction.
demagnetize then remagnetize in the desired
direction.
Ref: A.387
46. Cold working indications will & reapreappear if the
part is:
a.
b.
c.
d.
Ref: A.103.481-489
43. When it is believed that a discontinuity has been
removed by a grinding operation, the next
operation is to:
demagnetized then retested.
retested after stress relieving.
retested the opposite direction.
remagnetized at a higher amperage.
Ref: A.387-388
47. The unit of measure of one line of flux per
square centimeter of area is one:
a repair it.
b. sign off inspection of the part.
c. measure it to see if minimum thickness
a.
b.
c.
d.
~emains.
d. reexamine the area by magnetic panicle
testing.
Ref: A.398-400
ohm.
gauss.
ampere.
oersted.
Ref: C.24
48. The ability of matter to attract other matter to
itself is a phenomenon associated with:
,
a.
b.
c.
d.
magnetism.
field strength.
pole strength.
coercive force.
Ref: C.45, 12-13
Magnetic Particle Testing Method, Level 11
49. Materials which are strongly attracted to a
magnet are called:
a.
b.
c.
d.
54. The general term used to refer to a break in the
metallic continuity of the part being tested is:
a. discontinuity,
b. crack.
C. seam.
d. lap.
polarized.
magnetized.
nonmagnetic.
ferromagnetic
Ref: E.33
Ref: C.12-13
55. The pattern of iron powder sprinkled on a paper
placed over a bar magnet is called a:
50. Materials which are weakly attracted
magnetically are called:
a.
b.
c.
d.
a.
b.
c.
d.
diamagnetic.
nonmagnetic.
paramagnetic.
ferromagnetic
flux meter.
field survey.
magnetometer.
magnetograph.
Ref: C.13
51. Materials which are repelled magnetically are
called:
a.
b.
c.
d.
Ref: A.119, 169
56. The lines of force that form a path around a crack
in a ring magnet are called:
a.
b.
c.
d.
diamagnetic.
nonmagnetic.
paramagnetic.
ferromagnetic.
leakage flux.
field strength.
magnetic lines.
longitudinal field.
Ref: C.2, 17
Ref: C.13
52. The end of a magnet at which the lines of flux
are thought of as entering the bar is the:
a.
b.
c.
d.
57. Since the magnetic lines of force within a bar
magnet run the length of the bar, it is said to be:
a.
b.
c.
d.
north pole.
south pole.
positive pole.
negative pole.
randomly magnetized.
circularly magnetized.
permanently magnetized.
longitudinally magnetized.
Ref: C.12
53. A general rule to use for determining the
detectability of surface discontinuities by
magnetic particle inspection is that:
a. the depth and width have no bearing to each
other.
b. the depth should be at a one-to-one ratio to the
width.
c. the depth should be 20% of the material
thickness.
d. the depth should be at least five times the
width of the opening of the discontinuity at
the surface.
Ref: A.371
Ref: C.15
58. Lines of flux are thought to leave a magnet at
the:
a. north pole.
b. south pole.
c. positive pole
d. negative pole.
Ref: C.12
59. A break in the magnetic uniformity of a part that
is called a magnetic discontinuity is related to a
sudden change in:
' a. resistivity.
b. indtictance.
c. permeability.
d. capacitance.
Ref: A.127
Magnetic Particle Testing M e t w Level ZZ
60. In order to detect defects in different directions in
a material by magnetic particle inspection, it is
best to use:
a.
b.
c.
d.
only one field.
other pmbe locations.
a high frequency field.
two or more fields in different directions.
Ref: C.20
61. The p a are blanks cut from mlled iron bar
stock and have been mugh machined. Inspection
by continuous method reveals distinct but bmken
lines parallel (6.35 mm to 25 mm)(0.25 in. to
1 in.) with the axis on some of the pieces. These
indications are indicative of:
a.
b.
c.
d.
shrinkage.
nonmetallic inclusions.
surface checking.
machining tears.
Ref: C.4
62. A large forging is repaired by welding. Magnetic
particle inspection of the repair weld reveals a
s h q irregular indication running parallel with
the weld passes. It is located near the center of
the bead and starts and ends by tuning off
slightly from the axial direction. This indication
is indicative of:
a.
b.
c.
d.
inclusions.
crater cracks.
surface checking.
weld shrinkage cracks.
64. An example of a nomelevant indication that
would be classed as a magnetic discontinuity
rather than an actual discontinuity could be
caused by:
a
b.
c.
d.
corrosion.
a slag pocket.
grinding cracks.
a known abrupt change in the hardness of the
Part.
Ref: C.234
65. The detection of deep-lying internal defects in
heavy steel weldments at a depth of 6.35 mm
(0.25 in.) to 51 mm (2 in.) below surface is:
a. very improbable.
b. very similar to the detection of surface cracks.
c. simple if the defect's width can be
approximated.
d. not difficult if the defect is amibntable to fine
porosity.
Ref: C.233
66. In magnetic particle inspection, it is best to:
a. make sure that parts meet specified acceptance
criteria.
b. reinspect all questionable discontinuities to
ensure that no defective parts are accepted.
c. reinspectquestionable parts utilizing another
nondesbuctive test method.
d. make celtain that parts are better than
specified and contain no discontinuities at all.
Ref: A.413.416-417
Ref: A.441
63. The wattage most commonly used for mercury
vapor bulbs for portable fluorescent magnetic
particle inspection is:
a
b.
c.
d.
67. Subjecting a magnetized object to a magnetic
force that is continually reversing its d i i t i o n
and gradually decreasing in intensity is know as:
a.
b.
c.
d.
50 watts
75 watts
100 watts
200 watts
magnetization.
continuous method.
residual method.
demagnetization method.
Ref: C.31
Ref: (2.320-321
68. Any of these welding processes is susceptible to
a discontinuity known as slag inclusion except:
a.
b.
c:
d.
flux cored arc welding
submerged arc welding
gas tungsten arc welding
shielded metal arc welding
Ref: C.89
Magnetic Particle Testing Method, Level II
69. Which of the following induces a longitudinal
magnetic field?
a.
b.
c.
d.
prod
yoke
head shot
internal conductor
Ref: C.156
70. At the curie point, steel is temporarily
transformed from:
a.
b.
c.
d.
paramagnetic to diamagnetic.
ferromagnetic to diamagnetic.
paramagnetic to ferromagnetic.
ferromagnetic to paramagnetic.
0.3 ganss
0.03 gauss
0.003 ganss
3.0 gauss
75. A hysteresis curve describes the relation
between:
71. Magnetic field strength is measured in:
tesla.
ganss.
oersted.
weberdmz.
a. magnetizing force and flux density.
b. magnetizing force and applied current.
c. strength of magnetism and alignment of
domains within material.
d. magnetic flux density and current generated.
Ref: A.24
76. Demagnetization would be required if:
Ref: C.302
72. The following types of discontinuities can be
found in an object's subsurface except:
a.
b.
c.
d.
a.
b.
c.
d.
Ref: C.13
Ref: C.30
a.
b.
c.
d.
74. As a magnet, the Earth is surrounded by
magnetic lines of force. These lines of force
make up what is sometimes called Earth field
and they can cause problems in both magnetizing
and demagnetizing. However Earth field is weak
in the order of:
pipe.
hot tears.
cold shut.
segregation.
a.
b.
c.
d.
the material has low retentivity.
the object is to be electric arc welded.
the material has low reluctance.
heat treatment is to be carried out afler testing.
Ref: (2.30
77. One of the disadvantages of half-wave
magnetization is, when demagnetizing:
Ref: C.77
73. Which one of following materials has
permeability much greater than that of air?
a. permeability material
b. diamagnetic material
c.
material
d. ferromagnetic material
Ref: C.13
a.
b.
c.
d.
the current has skin effect.
the current does not reverse.
the current passes very deep.
the current passes only on the surface.
Ref: C.27-28
78. One disadvantage of using a single-phase
magnetic particle unit at current input values
over 600 A, in comparison with a three-phase
unit is, the single-phase unit will:
a.
b.
c.
d.
detect only surface discontinuities.
not detect subsurface discontinuities.
require 1.73 times more input current.
require 1.73 times less input current.
Ref: C.28
Magnetic Particle Testing Methoii, Level II
79. In longitudinal magnetization of a m u d bar,
residual magnetism will be:
a.
b.
c.
d.
greatest at the center of bar.
greatest at the ends of the bar.
the same all over on the bar.
the minimum at the ends.
Ref: C.293
80. Magnetic particles of varying size are used for
dry powder and wet methods. Typically, particle
sizes for wet method testing range from:
a. 1 to 5 micrometer.
b. 1 to 25 micrometer.
c. 100 to 500 micrometer.
d. 100 to 1000 micrometer.
Ref: C.35
8 1. Yokes of solid steel have been used for many
years to indicate transverse cracks. Alternating
current yokes are assembled from laminated
transformer sheet to reduce:
a.
b.
c.
d.
the size of the yoke.
production costs.
the weight of the yoke.
eddy current losses.
Ref: C.162
Magnetic Particle Testing Metho4 Level ZZ
Level I1 Answers
Magnetic Particle Testing Method
Level 111 Questions
Magnetic Particle Testing Method
1.
The magnetic domains in a permanent magnet
are aligned in:
4.
a. fixed positions with dictions that cancel out.
b. fixed positions, predominantly in one
direction.
c. the same d i c t i o n as the metal's grain
structure.
d. a random position and may become aligned to
attract a magnetic material.
Ref: C.12
2.
3.
a. Residual magnetism can disturb the welding
arc path on parts to be welded.
b. Residual magnetism may attract chips or small
particles in-service, causing galling or
mechanical wear.
c. Residual magnetism could interfere with the
operation or accuracy of instruments placed on
or near the part during service.
d. If the part is to be radiographed after magnetic
particle inspection, residual magnetism may
interfere with the electromagnetic radiation
spectrum.
Ref: C.30, 292-293
For which of the following would the wet
fluorescent technique be preferred over the dry
technique?
a. When the parts are large and bulky.
b. When increased speed and sensitivity are
desired.
c. When the parts being inspected are to be field
welded.
d. When it is desired to use the fluorescent
lighting provided in many plants.
Ref: A.345
5.
forging
grinding
casting
heat treatment
6.
Ref: A.88
Subjecting a part to a magnetic field that is
constantly reversing in polarity and gradually
diminishing in strength accomplishes which of
the following?
a.
b.
c.
d.
Gas, hot tears, cold shuts, shrinkage cracks and
sand inclusions are examples of defects resulting
from which of the following processes?
a.
b.
c.
d.
Which of the following statements is
a valid
reason for demagnetizing a part after completing
a magnetic particle test?
Magnetizes the part.
Demagnetizes the part.
Helps to locate deeplying defects.
Increases the strength of the retained magnetic
field.
Ref: C.31
The concentration of the solid content of a
suspension of magnetic particles is measured by:
a.
b.
c.
d.
weighing the suspension.
soaking the solids in benzol.
measuring the pull on a magnet.
permitting the solids to settle out of
suspension.
Ref: A.261-263
Magnetic Particle Testing Method, Level 111
7.
An important factor that must be considered
when selecting a method of magnetization is the:
a. part's curie point.
b. the location of the inspection station.
c. location of the inspection unit.
d. alloy, shape and condition of the part
Ref: A.229-243, C.154-157
8.
a. Move the direct current coil closer to the part.
b. Reduce the current in only one direction.
c. Move the alternating current coil further away
from the part.
d. Move the part toward the inner surface of the
coil
Ref: C.297-299
An important factor that must be considered
when selecting a method of magnetization is the:
a.
b.
c.
d.
9.
12. Which of the following will reduce a magnetic
field?
material's curie point.
type of magnetizing current.
color of the fluorescent particles.
availability of handling equipment.
Ref: A.229-243. C.154-157
When a magnetic material reaches its curie
temperature the material becomes:
13. When an external magnetizing force is removed,
some of the magnetic domains remain
preferentially oriented. The additional force
required to return them to their original random
orientation is commonly referred to as:
a.
b.
c.
d.
coercive force.
applied field force.
residual field force.
direct current electric force.
Ref: C.24
a.
b.
c.
d.
magnetic.
radioactive.
diamagnetic.
paramagnetic.
14. When a cylinder is magnetized by a central
conductor, the field is most intense:
Ref: C.293
10. Magnetic particle inspection methods on
ferromagnetic materials are recognized as
superior to liquid penetrant techniques when:
a.
b.
c.
d.
the surface is plated.
the parts are painted.
the surface is anodized.
dry particles are used for fine surface cracks.
Ref: C.389
I I. A paramagnetic material:
a.
b.
c.
d.
is highly magnetic.
is slightly magnetic.
bas no magnetic properties at all.
has a demonstrated lack of electron mobility.
Ref: C.13
a.
b.
c.
d.
at the ends of the cylinder.
at the outer surface of the cylinder.
at the inside surface of the cylinder.
halfway through the thickness of the cylinder
wall.
Ref: C.19. 152
15. When is the magnetic field strongest in an object
being inspected by the magnetic particle method?
a.
b.
c.
d.
While the magnetizing current is applied.
Just after the magnetizing current is shut off.
When the magnetic particle powder is applied.
Just prior to current reversal when using
alternating current.
Ref: C.24, 152
16. Which of the demagnetization methods listed
below is most effective?
a. full-wave rectified
b. half-wave rectified alternating current
c. direct current with reversing and step-down
control
d. variable voltage alternating current with
step-down control
Ref: C.300
Magnetic Particle Testing Method, Level III
17. When using the longitudinal magnetization
method to inspect a bar 152 mm (6 in.) long and
5 1 mm (2 in.) in diameter with a 5-turn coil,
which of the following amperage values should
be used?
a.
b.
c.
d.
1200A
3000A
12000A
2000 amp-turns
Ref: A.181-182
18. To examine a part 127 mm (5 in.) long and 51
mm (2 in.) in diameter using a 5-turn coil and
head stock magnetic particle machine, what
amperage should be used for longitudinal
magnetization?
a.
b.
c.
d.
21. If the same amperage is passed through a 25 mm
(1 in.) diameter bar and a 51 mm (2 in.) diameter
bar of the same length and material, the strength
of the magnetic field at the center of:
a. both bars will be 0.
b. the 25 mm (1 in.) bar will be one-half that of
the 5 1 mm (2 in.) bar.
c. the 51 mm (2 in.) bar will be one-half that of
the 25 mm (1 in.) bar.
d. the 25 mm (1 in.) bar will be approximately
one-fourth that of the 51 mm (2 in.) bar.
Ref: A.186-187
22. When a magnetic field is induced in a part with
prods spaced 152 mm (6 in.) apart, the field is a:
a.
h.
c.
d.
3000A
3600A
4500 A
10 000 ampere-turns
circular field.
residual field.
solenoid field.
longitudinal field.
Ref: C.22-23, 150-151
Ref: C.181-182
19. To examine a bar 381 mm (15 in.) long and
5 1 mm (2 in). in diameter using a 7-turn coil and
head-stock magnetic particle machine, what
amperage should be used for circular
magnetization?
a.
b.
c.
d.
750 A
1800A
1800 a m p - t u r n s
49 000 a m p - t u r n s
Ref: A.208
20. If the same amperage is passed through a 25 mm
and 51 mm (I in. and a 2 in.) diameter bar of the
same length and material, the strength of the
magnetic field at the surface:
a. will be the same for both bars.
b. of the 25 mm (1 in.) bar will be one-half that
of the 51 mm (2 in.) bar.
c. of the 25 mm (I in.) bar will be appmximately
twice that of the 5 1 mm (2 in.) bar
d. of the 51 mm (2 in.) bar will be approximately
four times that of the 25 mm (1 in.) bar.
Ref: A.186
23. When circular magnetization is used to detect
subsurface discontinuities, direct current is used
instead of altemating current because:
a. particle mobility is no longer a factor.
b. there is no logical reason to use direct current
instead of alternating current.
c. direct current saturates the magnetic particles
better than alternating current.
d. the skin effect of alternating current reduces
the maximum depth at which discontinuities
can be found.
Ref: C.27, 154-157
24. An inspection method in which an initial
magnetizing force is applied to a part and then
reduced to a lower continuous value is called:
a.
b.
c.
d.
the surge method.
the residual method.
the multivector method.
the continuous method.
Ref: A.155-156
Magnetic Particle Testing ~ e t h o dZ&velZZZ
,
25. When deciding to inspect a part by the residual
28. Which of the following, when used as the last
method of applying the particles, what factor
affects the residual magnetic field strength of the
part?
magnetizing method, will best render a part
suitable for relatively easy measurement of the
external magnetic field using a field indicator?
a.
b.
c.
d.
a.
b.
c.
d.
the retentivity of the part
the part's magnetic field saturation point
the direction of the magnetic field in the part
the type of field indicator used to measure the
residual field
Ref: A.237-240,C.37-38
probe magnetization
circular magnetization
longitudinal magnetization
central bar conductor magnetization
Ref: C.32-33
29. When using direct current an indication is
26. Factors that must be considered when
interpreting an indication are:
a. the direction of the magnetic field and location
of the magnetic particle unit.
b. the location of the magnetic particle unit and
the nondestructive testing level of the
inspector.
c. the orientation and shape of the indication and
the direction of the magnetic field.
d. the strength of the leakage field at the
indication and the type of demagnetization
method.
Ref: A.379,C.233-235
27. A 7-turncoil at 1000 A is used to inspect a round
solid part 381 mm (15in.) long and 64 mm
(2.5in.) in diameter. The length-to-diameter ratio
is:
a.
b.
c.
d.
2.14.
6.0.
7000 amp-turns.
45 000 amp-turns.
detected. What is the next logical step to
determine if the indication results from a surface
or subsurface condition?
a.
b.
c.
d.
Reinspect using alternating current.
Reinspect at higher amperage.
Demagnetize and apply powder.
Reinspect using the residual method.
Ref: A.397
30. Which of the statements below is most
appropriate concerning materials I and I1
represented by the hysteresis curves shown in
Figure l?
a. Material I is not a good subject for magnetic
particle inspection.
b. Material I could be used for dry powder
magnetic particles.
c. Material I1 could be used for dry powder
magnetic particles.
d. Material I1 is paramagnetic.
Ref: A.217
Ref: A181-182
Figure 1
Material I
B+ (Flux Density)
B- (Flux Density of Opposite
Polarity to B+)
Material I1
Magnelic Particle Testing Method Level 111
31. Considering the curves shown in Figure. 1,
material II in comparison to material I indicates
that the material:
a.
b.
c.
d.
has a high retentivity.
has a high permeability.
has a high coercive force.
would make an excellent permanent magnet.
Ref: A.217
32. Point B on the hysteresis c w e for material I
shown in Figure 1:
a. is the limit of coercive force.
b. is the material's magnetic saturation point.
c. represents the mid-point of the rectified
alternating current applied.
d. represents the point at which the residual
magnetic value will remain when the
magnetizing current is removed.
Ref: A.116-117
33. Which point on the hysteresis curve shown in
Figure. 1 represents the residual field value?
Ref: A.116-1117
34. When withbwing a part from the field around a
coil and without changing the d i i t i o n of
current, which of the following has the least
effect on demagnetizing the part?
a
b.
c.
d.
direct current
alternating current
full-wave rectified current
half-wave rectified alternating current
ReE C.297-299
be
35. The important factor below that should
considered when selecting a method of
magnetization to detect subsurface discontinuities
is:
a.
b.
c.
d.
available equipment.
wnf~gurationof the part.
skill of the operator of the equipment.
type of material the part is made from.
Ref: C.233
36. Which of the following discontinuities occur as a
result of the rolling process?
a.
b.
c.
d.
fissures
laminations
lack of peneh.ation
blowholes and pipe
Ref: C.5
37. Which of the following discontinuities occur as a
result of the forging process?
a.
b.
c.
d.
pipe
laps
laminations
lack of penetration.
Ref: C.7
38. If an indication is formed when using the
residual method as well as the continuous
method, it is most likely:
a.
b.
c.
d.
very deep and tight
a relevant indication.
a nonrelevant indication.
very shallow and open to the surface.
Ref: A.397
39. Plated parts can be reliably tested for fme surface
cracks using the magnetic particle method if the
plating is less than:
a.
b.
c.
d.
0.762 mm (0.03 in.) thick.
1.016 mm (0.04 in.) thick.
0.127 mm (0.005 in.) thick.
0.2032 mm (0.008 in.) thick.
Ref: A.247
40. The magnetic Lines of flux or flux in a permanent
magnet:
a. in all cases produce a longitudinal field.
b. enter the south pole and leave the north pole.
c. flow from the north pole through the magnet
to the south pole.
d. change direction 60 times a second with the
magnetizing current.
Ref: C.12
Magnetic Partick Testing Method, Level I11
41. Which of the following magnetization techniques
is &recommended for magnetic particle
testing?
a.
b.
c.
d.
vector magnetization
parallel magnetization
circular magnetization
longitudinal magnetization
46. When a magnetized ferromagnetic object is
exposed to a subsequent heating operation above
the curie point:
a.
b.
c.
d.
Ref: A.139, C.159
42. When attempting to demagnetize a part
containing a circular residual field:
47. A discontinuity caused by a welding operation is:
a. use a swinging cyclic field.
b. consideration of the material's hysteresis is
most important.
c. establish a longitudinal field and then proceed
with demagnetization.
d. using half-wave current with a head shot setup
and Jtep-down magnetization will ensure
complete removal of the residual field.
Ref: C.33.294
43. Small parts requiring demagnetization should be:
a. loaded in baskets and passed through an
alternating current coil.
b. loaded in a steel basket for better field
distribution.
c. processed through a demagnetization cycle
one at a time.
d. demagnetized after assembly to ensure
complete demagnetization of the entire
assembly.
Ref: A.314
44. The best shape for magnetic particles used in the
dry powder method is:
a.
b.
c.
d.
the marten site structure will occur.
the magnetic domains become random.
there is no change from its previous state.
the magnetic domains are reversed from their
previous state
Ref: C.30
globular.
elongated.
long and slender.
a mixhlre of elongated and globular.
a.
b.
c.
d.
creep crack.
segregation.
machining tear.
lameral tearing.
Ref: C.86
48. The most effective current to be used with dry
magnetic particle is:
a. direct current.
b. half-wave rectified alternating current.
c. full-wave rectified alternating current with
three-phase bridge circuitry.
d. full-wave rectified alternating current with
single-phase bridge circuitry.
Ref; C.155
49. The following properties should be considered in
choosing a vehicle for the wet method, except:
a capillarity.
b. corrosivity.
c. wetting ability.
d. foaming ability.
Ref: C.208
50. The amount of light reflected by one surface
compared to that reflected by another adjacent
surface is:
Ref: C.36
45. The best method for testing ball bearings is:
a.
b.
c.
d.
along one axis using a coil.
two head shots along the X and Y axis.
two shots using a coil at the X and Y axis.
induced current shots along X, Y,and Z axis,
rotating 360 degrees during each shot.
Ref: A.349-350
a.
b.
c.
d.
length-to-diameter ratio.
B/H ratio.
color contrast.
brightness contrast.
Magnetic Particle Testing Method, Level ZZZ
51. Given a certain continuous magnetization current
in a material, which type of current would give
the deepest penetration?
a
b.
c.
d.
direct current
altematjng current
direct current surge
half-wave direct current
Ref: C.157
52. Given a certain continuous magnetization current
in a material, which type of current would give
the shallowest penetration?
a
b.
c.
d.
direct current
alternating current
direct current surge
half-wave direct current
a. Tbe magnetic field follows the path of greatest
reluctance.
b. Coil shot. wet method provides only surface
discontinuities.
c. The head shot wet method is better for
detecting subsurface discontinuities.
d. In most cases the continuous method is more
sensitive than is the residual method.
Ref: C.37
57. Which one of the following magnetic particle
testing techniques is logically acceptable for
testing a large flat area?
Ref: C.157
53. Which type of radiation can most damage human
tissue?
a
b.
c.
d.
56. One of most important facts that must be
remembered wbile establishing magnetic particle
procedure.
W-A
W-B
white light
visible Light
a.
b.
c.
d.
prod
rod shot
coil shot
head shot
Ref: C.158
58. Permeability of a material can be numerically
written as:
Ref: C.322
54. Compared with magnetic particle testing, liquid
penetrant testing is nnt reliable after paint
removal from weld because:
a. Liquid penetrant testing can be applied only to
small parts.
b. Liquid penetrant testing can be applied only in
field conditions.
c. magnetic particle testing will detect subsurface
discontinuities.
d. partial smearing of weld surface metal across
the discontinuity opening can occur.
Ref: C.389
55. Prod spacing less than 76.2 mm (3 in.) is usually
not practical because:
a. the possibiity of sparking will increase.
b. more time will be consumed for inspection.
c. it requires more media than a 152 mm (6 in.)
prod distance.
d. particles tend to bend around the prod making
interpretation difficult.
Ref: C.151
a.
b.
c.
d.
RIB.
BM.
HcNb.
ampere tumdnomber of turns.
Ref: C.26
59. One disadvantage for using undyed wet magnetic
particles is:
a. it is more costly.
b. it is suitable for the fluorescent method only.
c. it is suitable for surface discontinuity detection
only.
d. the lack of contrasting color makes them
difficult to see.
Ref: C.35
Magnetic Particle Testing Method, h v e l ZZZ
60. One of most desirable characteristics of the
media for magnetic particle testing is:
a. the ability to show clearly against any
background.
h. the insensitiveness to concentration in water as
vehicle.
c. no need for agitation when used with liquid
vehicle.
d. the highest possible permeability and lowest
retentivity.
Ref: C.34
Magnetic Particle Testing Method, Level 111
Level 111Answers
Magnetic Particle Testing Method
Sample Specification
Wet Magnetic Particle Testing Method
1.0
seope
1.1
2.0
2.6
Magnetic particle testing is a
nondestructive testing method used to
detect surface and near surface
discontinuities in ferromagnetic materials.
2.7
General
2.1 The Magnetic Particle Testing Method
2.2
2.3
2.4
2.5
consists of magnetizing the area to be
inspected, and then applying magnetic
particles to the surface of the test area.
Magnetic field leakages caused by cracks
and other discontinuities will attract the
magnetic particles, and the resulting
pattern will be characteristic of the type of
discontinuity present. Sensitivity of the
Magnetic Particle Testing Method is
greatest at the surface and diminishes
rapidly with increasing depth.
Drawings and purchase orders should
specify the extent of magnetic particle
inspection required for each item and the
acceptance standards to be met.
Documents referenced, as modified
herein, shall be considered part of this
standard procedure.
All persons performing magnetic particle
inspection shall have received training
and be certified in accordance with a
written program developed per
recommended g u i d e l i s of SNT-TC-IA
(1980 Edition).
2.4.1 A Level I certified technician shall
perform work under the direction
of a Level II, except that fmal
interpretation shall be performed by
a Level II or Level Ill. AU reports
and technique sheets shall be
prepared by a Level 11, and the
technique sheet approved by a
Level Ill.
A minimum of two separate examinations
shall be conducted on each area inspected,
with the lines of flux of one examination
approximately perpendicular to the l i e s
of flux of the other. A different method of
magnetization may be used for the second
examination (i.e., longitudinal magnetic
field technique and circular magnetic field
technique).
2.8
An ammeter shall be used on the magnetic
particle inspection unit to ensure that the
proper amperage is being applied.
In the absence of requirements to the
conhay, magnetizing currents shall be
determined by experiment, and recorded
on a magnetic particle technique sheet and
approved by a Level III.
2.7.1 The behavior of the magnetic
particles on the surface of a test
part while it is being magnetized is
an excellent indication of the
amount of magnetizing current
being used, or the strength of the
magnetic field. Complete lack of
particle activity indicates that the
field is too weak, excessive particle
accumulation with lack of particle
mobility indicates that the field is
too strong. Some slight indication
of pattern around ends, edges, and
protuberances indicates sufficient
field strength. A special carbon
steeVcopper plate field indicator
may be used to determine
comparative field strength. If
clearly defied lines of particles
appear on the copper side of the
field indicator, the magnetic field is
of sufficient strength.
2.7.2 When particle activity indicates
either insufficient or excessive field
strength, even though all test
parameters have been met, a
change in current value shall be
recorded on the magnetic particle
technique sheet.
Continuous exposure to the wet particle
bath can cause subcutaneous fats and oils
of the skin to be dissolved. The resultant
drying and cracking encourages secondary
infection. Persons suffering rashes and
skin initation from exposure to the wet
particle bath should report this condition
to the supervisor.
2.8.1 Good working habits which prevent
the unnecesc& wetting of hands
and cloth~ne9hould be develooed.
2.8.2 The use of a hand protective
preparation is recommended when
-
35
Sample Specifitation
2.9
3.0
Referenced Doenments
3.1
4.0
ASME Section V Nondesttuctive
examination ASTM E-125 Reference
photographs for magnetic particle
inspection
ASTM E-138 Wet magnetic particle
inspection ASTM E-269 Terms relating to
magnetic inspection
PROC. M-1 Calibration of magnetic
particle test method equipment
PROC. M-2 Care and maintenance of
equipment
PROC. M-4 Mixing and checking
magnetic particle bath
3.1.1 All documents referenced in this
section shall be maintained to the
latest revision, and work requests,
technique sheets, and test reports
will cite the proper revision for the
work performed.
5.2
6.0
4.2
Identification methods shall be established
which will enable the test report, the
component, and the area tested to be
identified with respect to each other at any
time.
A suitable method shall be used to ensure
correct part identification. Where
identification is removed or obliterated, an
identity tag shall be used until the
identification can be reapplied. If positive
identification cannot be determined, then
a nonconformance report shall be issued.
6.1
6.2
6.3
7.0
With most magnetic particle test methods,
satisfactory results may generally be
obtained when the surface to be inspected
is in the as-welded, as-rolled, as-cast, or
as-forged condition. However, in some
cases, surface conditioning may be
required to prevent the masking of
defects.
5.1.1 Surfaces to be inspected shall be
clean and free from oil, grease,
8.0
The wet magnetic particle inspection unit
is a horizontal stationary unit
Company,
manufactured by
Model No.
,2000 DC amps,
equipped with head-tail stocks and a
5-turn coil.
The demagnetizing unit is a 60-cycle,
single phase AC, coil-type with timer,
manufactured by Company, Model No.
The field indicator is a dial readout,
pocket size magnetometer used to
measure comparative magnetic field
strength.
Examination Medium
7.1
Surface Condition
5.1
sand, loose rust or scale, which
may interfere with satisfactory
inspection.
5.1.1.1 Surfaces to be inspected
shall be cleaned prior to
submission to NDT. When
the surface condition is not
suitable for inspection, the
part shall be returned to
production untested, or
NDT will condition the
surface, whichever is
mutually agreeable.
5.1.2 Small openings and holes which
lead to areas from which it would
be difficult to remove magnetic
substances shall be plugged before
the part is inspected.
Unless otherwise specified in the drawing,
final magnetic particle inspection shall be
performed on any part in the f ~ s h e d
surface condition, and final heat treated
condition.
Equipment
Identification
4.1
5.0
working for extended periods with
the wet particle bath.
2.8.3 A polyvinyl apron shall be worn.
2.8.4 After working with the wet particle
bath, hands and arms should be
washed with warm water and mild
soap.
Care and maintenance of magnetic
particle test equipment shall be performed
in accordance with instructions provided
in procedure M-2.
The examination medium shall consist of
finely divided ferromagnetic particles
which have high permeability and low
retentivity characteristics.l They shall be
of suitable size and shape to readily
produce magnetic particle indications.
7.1.1 Fluorescent magnetic particles shall
be used.
Methods of Examination
8.1
8.2
The methods of "wet" magnetic particle
examination used shall consist of the
longitudinal magnetic field technique and
the circular magnetic field technique.
Using the longitudinal magnetic field
technique, magnetization is accomplished
I ~uspodcdin bsy oil "i? as described in Rrr. No.MT4.
2 ih put to bc i n s W is placed witbio the coil aascmbly or flexible
lcods pn coiled thrmgh large wmplci pans.
Sample SpeciFation
by passing current through a multi-turn
coil.2
This technique produces a longihldiinal
magnetic field parallel to the axis of the
coil.
8.2.1 Direct or rectified AC shall be
used. The magnetizing current is
determined by dividing 45 000 by
the length-over-diameter ratio of
the part to be inspected, and then
dividing this value by the number
of turns in the coil.
Amperes =
9.2
9.3
Ampere-tums
No. coil turns
9.4
Using the circular magnetic field
technique, magnetization is accomplished
by passing current through the part to be
inspected. This technique produces a
circular magnetic field throughout the part
perpendicular to the current flow.
8.3.1 Direct or rectified AC shall be
used. The magnetizing current is
determined by multiplying the part
diameter by an amperage-per-inch
diameter value.
8.3.2 The magnetizing current shall be as
shown in the table.
Part Diameter
0-250 mm (0-10 in.)
Over 250 mm (10 in.)
Amperes per Inch of Part Diameter
500-800 A
9.5
9.0
Examination
9.1 A pre-inspection visual examination shall
be made of the test part to determine
surface condition, equipment
requirements, and also that all test
parameters can be met.
9.1.1 When any material or part cannot
be fully inspected as required by
drawing, due to design, test facility
restrictions, or other reasons, a
nonconformance report shall be
issued. The nonconformance report
shall state the reasons why the part
cannot be fully inspected, and
recommended appropriate action.
The magnetic particle test report
shall state the test Limitations.
Unless otherwise specified by drawing,
magnetic particle inspection shall be
performed by the continuous method. This
is accomplished by keeping the
magnetizing current on while the
examination medium is being applied (by
flowing it over the part).
The sequence of "shots" shall be
determined by ascending order of current.
That is, the "shot" requiring the lowest
amperage shall be fust, and the "shot"
requiring the greatest amperage value
shall be the product of the amperage
multiplied by the number of turns in the
coil.
9.3.1 When exceptions to 9.3 are
necessary, this shall be indicated by
the order of listing for each shot on
the technique sketch.
Examinations shall be performed with
sufficient overlap to ensure 100%
coverage of the area or part under
inspection at the established field strength.
9.4.1 When using the longitudinal
magnetic field technique, no length
greater than 229 mm (9 in.) of test
part extending from each side of
the coil shall be inspected with
each "shot." Therefore, if a part is
longer than 460 mm (18 in.), two
or more "shots" along its length
will be necessary.
9.4.2 When using the circular magnetic
field technique, no length greater
than 310 mm (12 in.) shall be
viewed during any one "shot."
Therefore, if a part is longer than
310 mm (12 in.), two or more shots
will be necessary.
Repaired areas on the test part shall be
reinspected in accordance with the
original test procedures.
10.0 Evaluation of Indications
10.1 Evaluation of indications shall be to
acceptance standards shown on drawings
or purchase orders.
10.2 The inspection area shall be provided with
adequate lighting to facilitate examination
of the test part for indications.
10.2.1 The examination shall be conducted
in a darkened area under ultraviolet
light illumination.
10.2.2 The ultraviolet light shall emit
near-ultraviolet radiation in the
330-390 nm (3300-3900 A)
wavelength range.
Sample Specification
10.3
10.4
10.5
10.6
10.7
10.8
10.2.3 The ultraviolet light shall have, as a
minimum, an intensity of
800 kWIcm2 at the inspection
surface, as measured by XYZ
Company light meter (or equal),
with a 10X multiplier disk.
The ultraviolet light shall have a
minimum warm-up time of 5 minutes
prior to its use in examination.
Relevant indications are indications that
result from discontinuities withii the test
Part.
Nonrelevant indications ate indications
that result from excessive magnetizing
current, structural design, or permeability
variances within the test part. They have
no bearing on the suitability of the test
part for service.
10.5.1 Any indication believed to be
nomelevant shall be regarded as
relevant and shall be reexamined to
determine whether an actual defect
exists. Surface conditioning may
precede the reexamination.
10.5.2 If test part quality cannot be
ensured by magnetic particle
inspection upon re-examination,
then other methods of
nondestructive testing may be used.
Decisions concerning nonrelevancy
require Level I11 approval.
Linear indications shall be considered as
those having a length more than three
times the width.
Rounded indications shall be considered
as those having a length less than three
times the width.
Aligned indications shall be considered as
a group of three or more indications
which touch an imaginary straight line
connecting any two of the group.
11.0 Demagnetization
11.1 Demagnetization shall be required
following final magnetic particle
inspection, where residual magnetism will
interfere with subsequent processes or
usage.
11.2 Only the demagnetizing unit shall be used
for demagnetization. Do not use the coil
on the wet magnetic particle inspection
unit for demagnetization.
11.3 Energize the demagnetizing coil by
operating the timer switch. This timer
limits the operating periods from a few
seconds to one minute, as selected. The
red light will glow and a strong pull will
be felt on a piece of ferromagnetic
material held near the coil.
11.3.1 CAUTION: Due to high currents,
operation should be intermittent.
That is, each operating period
should be followed by an equal
period of rest, to allow for cooling.
The maximum "on" period should
seldom be longer than 30 seconds.
11.4 To demagnetize a part, turn on the current
and pass the part completely through the
demagnetizer. The part shall be placed
inside the coil and then slowly withdrawn
from the magnetic field in a straight line,
a distance of at least 1.2 m (4 ft).
11.4.1 CAUTION: Do not allow the
current to turn off while the part is
in the magnetic field, as incomplete
demagnetization may result. Repeat
the demagnetization process if this
occurs.
11.4.2 Small parts, much smaller in
cross-section than the demagnetizer
coil cross-section, should be passed
through the coil close to one wall
or comer and not through the
center of the coil.
11.5 For parts too large to pass through the
demagnetizer coil, satisfactory
demagnetization can often be
accomplished by bringing the part as close
as possible to the coil, tuming it to bring
all sides into the field, and then
withdrawing it slowly before the current
turns off.
11.6 Striking the part with a mallet while the
part is in the magnetic field and being
withdrawn will often improve results on
parts difficult to demagnetize.
11.7 Demagnetization may often be improved
bv the "Tranh~entCurrent Method." The
part to be demagnetized is placed in the
demagnetizer coil, the current turned on
and off several times, and then while the
current is on, the part is withdrawn from
the magnetic field as described in 11.4.
11.8 The demagnetizer should be positioned so
that an imaginary line drawn through the
center of the coil runs in the east-west
direction.
11.9 A field indicator shall be used to
determine the amount of residual
magnetism remaining in the part.
11.10 Cleaning should occur prior to complete
drying of residual bath.
11.10.1 The test part shall be cleaned by
wiping it with a cloth soaked in
base oil "C." After the test part
has dried, a light coat of mineral
oil shall be applied as a rust
preventative.
Sample Speci&&n
12.0 Records
12.1 A magnetic particle inspection technique
sheet shall be submitted with the final
inspection records.
12.2 A magnetic particle inspection report shall
be submitted with the final inspection
records.
12.3 A maintenancelcalibration record shall be
kept (current) on the wet magnetic particle
inspection unit.
12.4 A wet magnetic particle inspection use
record shall be kept (current) on the wet
magnetic particle test unit.
12.5 All records of inspection, original, repair,
and final, shall be retained for a minimum
period of seven (7) years.
Sample Specification Questions
Sample Specification Questions
Wet Magnetic Particle Testing Method
Using the sample specification located on pages 3539, answer the remaining questions. (References listed
pertain to paragraphs in the sample specification.)
1.
5.
Part position is varied in the coil when the part
is:
a.
b.
c.
d.
The magnetic particles suspended in the bath
shall have:
over 46 cm (18 in.) in length
over 31 cm (12 in.) in length
square
round
Para. 9.4.1
a.
b.
c.
d.
2.
determine the polarity of magnetization
determine the amperage being used
ensure that the part has been demagnetized
measure amp-turns
Para. 2.6
Demagnetization is required:
a.
b.
c.
d.
as soon as the part has been cleaned
prior to magnetic particle inspection
for aU parts which are inspected
where residual magnetism will interfere with
subsequent processes or usage
Para. 11.1
Inspected parts requiring repair must be:
a.
b.
c.
d.
reinspected using a sampling plan
reinspected following repair
inspected with another NDT method
made to follow the original fabrication plan
after defect removal is checked and reworked
Para. 9.5
7. Ultraviolet light intensity requirements specify:
a. a minimum of five minute warm-up
b. that a darkened room be used
c. a minimum of 800 pWIcm2 at the inspection
surface
d. all of the above
Para. 10.2
The field meter is used to determine:
a. magnetic polarity and amperage
b. the comparative strength of field and if
demagnetization is effective
c. retentivity and magnetic permeability
d. both a and b
Para. 6.3; 11.9
4.
6.
The ammeter is used to:
a.
b.
c.
d.
3.
high red iron oxide content
low retentivity and low permeability
low retentivity and high permeability
high permeability and low coerciveness
Para. 7.1
8.
The ammeter shall be checked against a
calibration shunt meter:
a.
b.
c.
d.
prior to each use
at the start of the shift
per Procedure M-1
per Procedure M-4
Para. 3.1
Sample Specifiation Questions
9.
14. Unless otherwise specified, magnetic particle
inspection shalt be performed by:
Pam will be demagnetized by:
a. banging with a hammer
b. placine. witbin a demagn&i
- wil for 30
-&on&
c. holding within the demagnetiziig mil while
the stepdown transformer moves through its
descending order of amperage shots
d. setting the demagnetizing current at an
amperage higher than the original magnetizing
current and slowly passing the part through
the wil
Para. 11.4
10. When magnetizing a part, 31 cm (12 in.) long by
64 m m (2.5 in.) diameter, by placing it within
the head stocks and passing an electric current
through it, the ammeter should be set at:
a.
b.
c.
d.
the residual method
the continuous method
both a and b
none of the above
Pam 9.2
15. Unless otherwise specified, the final magnetic
particle inspection shall be performed on parts:
a. prior to final machining but after f i a l heat
treatment
b. after final machining but before final heat
trearment
c. after final machining and beat treatment
d. any time prior to final heat treatment
Para.5.2
16. The extent of magnetic particle inspection should
be specified:
Para 8.3.2
11. For demagnetization, the maximum "on" period
should seldom be more than:
a.
b.
c.
d.
in the procedure
in the drawings and in the purchase order
in the acceptance standard
by normal shop practice
Para.2.2
a.
b.
c.
d.
5 seconds
30 seconds
120 seconds
240 seconds
17. The technique sheet shall be approved by:
Para. 11.3.1
12. If a pan cannot be fully inspected as required by
the drawing:
a. a Level II
b. a Level III
c. no one; techniques used do not need to be
approved
d. a Level II and the client
Para.2.7
a.
b.
c.
d.
a drawing revision must be issued
the part must be scrapped
a nonconformance report must be issued
the part must be marked with red paint
pending disposition
Para. 9.1.1
13. The sequence of "shots" shall be determined by:
a.
b.
c.
d.
accessibility of areas
descending order of current
ascending order of current
this is not an important consideration
18. If the magnetizing current is not specified, the
magnetizing current should be determined by:
a. experimentation and then recorded on the
technique sheet
b. the cognizant engineer
c. the client
d. the technician's experience
Para.2.7
Para.9.3
Sample Specijkation Questions
19. Nonrelevant indications:
24. The part shall be post-cleaned:
a. have no bearing on the suitability of the part
for service
b. shall be reexamined to determine whether an
actual defect exists
c. must be completely removed
d. both a and b must be considered
Para. 10.5, 10.5.1
20. The intensity of the ultraviolet light shall be
measured using a:
a.
b.
c.
d.
Light meter with a 10X multiplier disc
Light meter with an amber field filter
light meter set at 343 nm (3425 A)
light meter with an M2 rating
Para. 10.2.8
21. A part being demagnetized should be slowly
removed from the magnetic field in a straight
line for a distance of:
a.
b.
c.
d.
31 cm (1 ft)
61 cm (2 ft)
122 cm (4 ft)
the distance is not important
Para. 11.4
22. Records of inspection shall be maintained:
a.
b.
c.
d.
for the life of the part
for 40 years
for 7 years
until the client accepts the part
Para. 12.5
23. A field indicator shall be used to determine the:
a. amount of residual magnetism remaining in a
Part
b. orientation of the magnetic field
c. overall vector component of the magnetic field
d. outer limit of magnetic field
Para. 11.9
a. by rinsing it with acetone
b. by wiping it with a dry cloth
c. by wiping it with a cloth soaked in base oil
"c"
d. this is not a provision of the procedure
Para. 11.10.11
25. Demagnetization may often be improved by the
use of:
a.
b.
c.
d.
the DC surge technique
insulated paramagnetic rails
the 'Transient Current Method"
a booster-type demagnetizer
Para. 11.7
Sample Specijkation Questions
S a m ~ l eS~ecificationAnswers
c
Testing Method
Wet ~ a g n e t iparticle
Supplement to Recommended Practice SNT-TC-IA
(Q&A Book): Magnetic Particle Testing Method
Text Corrections
The following text corrections apply to the first printing of Supplement to Recommended Practice
SNT-TC-1A (Q&A Book): Magnetic Particle Testing Method, second edition. Subsequent printings of the
document will incorporate the corrections into the published text.
Page 3: Question 27 should be changed as follows:
A metal that is difficult to magnetize is said to have:
27.
a high permeability.
b, low permeability.
c. low coercive force
d. low retentivity.
Ref: C.45
Answer b is correct.
Page 4: Questions 34 and 38 should be changed as follows:
34.
Which of the following is the most effective method for the detection of ear surface defects?
a Dry residual method using DC with surge.
b. Wet continuous method using half-wave rectified current.
c. Wet residual method.
d. Dly continuous method using half-wave rectified current with prods.
Ref: C.207
Answer d is correct.
38.
When there is absolutely no pattern or distribution of magnetic particles on the part, the possible
cause is that:
a. the amperage setting is too high.
b. the amperage setting is too low.
c. the particle bath strength is too high.
d. the part is made of steel with high retentivitv.
Ref: A.64
Answer h is correct.
Page 6: Questions 52 and 53 should be changed as follows:
52.
What equipment is used to determine if a pan has been demagnetized?
a. a magnet on the part
b. a field indicator
c. a survey meter
d. careful observation for clinging magnetic particles
Ref: C.302
Answer b is correct.
53.
Which of the following is most often used for dry magnetic particle inspection?
a. full cycle direct current
dim3 current
b. half wave
c. high voltage, low amperage current
d. direct current from electrolytic cells
Ref: C.202
Answer b is correct.
Page 11: The answers to the following Level I questions should be corrected as follows:
Level II
Page 17: Question 3 1 should be corrected as follows:
Which of the following is the most common current method used for preserving and documenting
31.
magnetic particle indications?
a hand drawn sketch
b. color-tinted tape
c. color-tinted lacquer
d. digital ~hotosraohy
R e f C: 284
Answer d is correct.
Page 19: Question 56 should be changed to read:
The lines of force that form a path around a crack in a ring magnet are called:
56.
a. h k g e flux leaka.e
b. field strength
c. magnetic lines
d. longitudinal field
Ref: C.2.17
Answer a is correct.
Page 21: Questions 71 and 76 should be corrected as follows:
Magnetic field strength is measured in:
71.
a. tesla
b. gauss
c.B webers!m2
d. arnpereimeter
Ref: C.302
Answer d is correct.
76.
Demagnetization would most likely be required when:
a. the material has low retentivity.
b. the object is to be electric arc welded.
c. the material has low reluctance.
d. heat treatment is to be canied out after testing.
Ref: C.30
Answer b is correct.
Page 23: The answers to the following Level I1 questions should be corrected as follows:
51. a
53. d
62. d
71. d
Page 25: Question 6 should he changed to read:
6.
The concentration of the solid content ef h a suspension of magnetic particles is measured by:
a. weighing the suspension
b. soaking the solids in benzol
c. measuring the pull on a magnet
d. permitting the solids to settle out of suspension
Ref. A.261-263
Answer d is correct.
Page 26: Delete Question 8.
Page 29: Questions 35 and 40 should be changed to read:
important factor below that should Ree be considered when selecting a
35.
The
method of magnetization to detect subsurface discontinuities is:
a. available equipment
b. configuration of the part
c. -cost
the equipment
d. type of materials the part is made from
Ref: C.233
Answer c is correct.
40.
The magnetic lines of flux && in a permanent magnet:
a in all cases produce a longitudinal field
b. enter the south pole and leave through the north pole
c. flow from the north pole through the magnet to the south pole
d. change direction 60 times a second with the magnetizing current
Ref: C.12
Answer b is correct.
Level III
Page 30: Question 47 should be changed as follows:
47.
A discontinuity caused by a welding operation is:
a creep crack.
b. se,mgation.
c. machining tear.
d. kmdla tearing.
Ref: C.86
Answer d is correct.
Catalog t2027
second edition first printing 03/07
Text Corrections printed 05/09
The American Society
for Nondestructive Testing, Inc.
ISBN-13: 978-1-57117-1474
Order # 2027R