Level 1 Flashcards
Waves used in ultrasonic testing of materials are ___________ in nature.
a) mechanical
b) magnetic
c) electromagnetic
d) harmonious
A
In a longitudinal wave, zones of compression alternate with________ zones.
a) dead
b) rarified
c) subduction
d) anticline
B
Elastic waves can be transmitted in
a) air
b) water
c) solids
d) all of the above
D
The smallest distance between two points on an elastic wave where the particles are in the same state of motion is the a) period b) wavelength c) frequency d) hypotenuse
B
The maximum displacement of a particle from its point of rest in a sound wave is its a) velocity b) amplitude of movement c) frequency d) wavelength
B
Particle motion in a longitudinal wave is a) parallel to the direction of wave propagation b) at right angles to the direction of wave propagation c) retrograde d) in counterclockwise ellipses
A
In transverse waves, particle motion is a) parallel to the direction of wave propagation b) right angles to the direction of wave propagation c) retrograde d) in counterclockwise ellipses
B
Rayleigh waves are a phenomenon associated with a) solid to liquid boundaries b) solid to air boundaries c) solid to solid boundaries d) all of the above
D
Surface waves limited on two surfaces are also called a) long. waves b) lamb waves c) shear waves d) P waves
B
Rayleigh, shear and longitudinal describe a) wave forms b) wave modes c) wave lengths d) wave guides
B
In general, the result of two waves interacting on each other can be found by a) strobe lighting b) vector addition c) cross-multiplying d) linear summation
B
The point where no particle displacement occurs on a standing wave is called a) an anticline b) an antidnode c) a node d) a dead zone
C
The point where maximum particle displacement occurs on a standing wave is called a) an anticline b) an antinode c) a node d) a peak detector
B
Wavelength of sound is determined by a) (velocity) / (frequency) b) (frequency) / (velocity) c) (frequency) X (velocity) d) none of the above
A
Compared to water, the acoustic impedance of steel is a) higher b) lower c) about the same d) higher or lower depending on the wave mode
A
2,500,000 cycles per second (cps) is also expressed as a) 25 kHz b) 2.5 MHz c) 2.5 mHz d) 25 GHz
B
The product of acoustic velocity times the density of a material gives a) power intensity b) frequency c) wavelength d) acoustic impedance
D
In steel, shear wave velocity as compared to longitudinal wave velocity is about a) twice as fast b) the same c) one half as fast d) one quarter as fast
C
The usual form of denoting acoustic impedance is a) Z b) A c) I d) R
A
If a material borders on empty space the interface is called a) a vacuum b) infinity c) a free boundary d) none of the above
C
In determining the coefficient of reflection, a negative value indicates a) reduced amplitude b) loss of sound pressure c) phase reversal relative to the incident wave d) none of the above
C
Phase reversal of an ultrasound wave upon reflection from a sonically softer material is indicated by a) a zero R value b) a negative R value c) an R value greater than 1 d) increased resonance
B
Incidence of a sound wave from a solid to a gas is considered a free boundary condition because a) there are no particles in a gas b) all sound is lost in transmission c) the acoustic impedance of a gas is essentially zero d) none of the above
C
Bending of a sound wave upon entering a new medium is explained by a) Krautkramer’s law b) Snells’s law c) Boyle’s law d) Hooke’s law
B
If a sound beam is incident on steel from water at 20 degrees, the refracted transverse wave will have an angle a) greater than 20 degrees b) less than 20 degrees c) about 20 degrees d) that cannot be determined
A
The change from longitudinal to transverse waves (and visa versa) at a boundary is called a) Snell’s law b) mode conversion c) reciprocity d) reversal
B
The incident angle at which the transmitted longitudinal wave first ceases to exist in the defracting medium is called the a) longitudinal angle b) short angle c) first critical angle d) second critical angle
C
The incident angle at which the transmitted transverse wave first ceases to exist in the refracting medium is called the a) long angle b) short angle c) first critical angle d) second critical angle
D
The critical angle for the longitudinal wave is also called the a) right angle b) snell angle c) first critical angle d) second critical angle
C
The critical angle for the transverse wave is also called the a) right angle b) Snell angle c) first critical angle d) second critical angle
D
Mode conversion in ultrasonics occurs at a) defects b) corner reflectors c) only free boundaries d) all boundaries
D
For a longitudinal wave entering a medium of lower acoustic velocity, the refracted longitudinal wave angle in the new
material will be
a) totally internally reflected
b) the same
c) less than incidence angle
d) greater than incidence angle
C
The law of reflection requires that
a) the angle of reflection equals the angle of incidence
b) the normal to the reflecting surface, the reflected ray and incident ray lie in the same plane
c) both a and b
d) none of the above
C
The “bending” of sound waves at gaps and openings is accounted for by
a) reflection
b) diffraction
c) density
d) acoustic pressure
B
According to geometric-optic treatment of sound, acoustic pressure
a) increases with distance from source
b) decreases with distance from source
c) varies unpredictably with distance from source
d) none of the above
B
Reflection and refraction phenomenon are illustrated in geometric-optic treatment of ultrasound by means of
a) mirrors
b) equations
c) rays and straight lines
d) none of the above
C
In practical ultrasonic testing, mirror surfaces can be used with
sound beams to
a) image flaws
b) reach points of difficult access
c) reduce scatter
d) reduce short wave dispersion effects
B
The interference pattern produced in front of a transducer face
is a result of
a) rarefaction
b) dispersion
c) diffraction
d) refraction
C
The distance from the probe face to the last main maximum on the
beam axis is called the
a) near field
b) far field
c) dead zone
d) ozone
A
Acoustic pressure fluctuates in the near zone due to
a) diffraction interference
b) dispersion
c) refraction
d) density fluctuations
A
A longitudinal wave generating transducer will have a given near
field in steel. If in water the near field for this probe will
be
a) the same distance
b) about half as long
c) about 1/4 as long
d) about 4 times as long
D
Acoustic pressure along the beam axis moving away from the probe
has various maxma and minima due to interference. At the end of
the near field pressure is
a) a maximum
b) a minimum
c) the average of all maxima and minima
d) none of the above
A
Beyond the near zone of an ultrasound beam from a probe is the
a) dead zone
b) Fresnel zone
c) far field
d) null zone
C
Variations in acoustic pressure at right angles to the probes’
sound beam in the near zone are a result of
a) side lobes
b) overtones
c) sub harmonics
d) divergence
A
The angle of divergence is
a) constant for a given piezoelectric material
b) applicable to the far zone only
c) increases with increasing probe dimensions
d) decreases with increasing wavelength
B
The “main lobe” of a rectangular probe is
a) axially symmetric
b) broader in the small probe dimension
c) narrower in the small probe dimension
d) two dimensional
B
Focusing of ultrasound is accomplished by
a) curved piezoelectric crystals
b) lenses
c) both a and b
d) none of the above
C
Difficulties determining exact lateral location and relative size
of a flat reflector in the near zone result from
a) the dead zone
b) ring down
c) multiple maxima and minima
d) absorption
C
AVG (or DGS in English) diagrams are used for
a) establishing gain settings
b) determining vertical beam spreads
c) estimating flaw size
d) none of the above
C
Flaw detection using the through transmission method can give
accurate information about
a) flaw depth
b) flaw type
c) flaw orientation
d) none of the above
D
In ultrasonic testing, a wave pulse contains
a) a single well defined frequency
b) a range of frequencies
c) two full cycles
d) only positive going waves
B
The main contribution to loss of sound pressure of a beam
incident on a rough surface is provided by
a) scatter
b) mode conversion
c) refraction
d) diffraction
A
More scatter of a sound beam is had when using
a) high PRF
b) short pulse lengths
c) higher frequency probes
d) lucite delay lines
C
For best results detecting a defect that may be irregularly
shaped and slightly off perpendicular to the beam, the wavelength
used should be
a) the size of the defect
b) as small as possible
c) as large as possible to locate the defect
d) 1 MHz
C
In ultrasonic testing by pulse-echo method, the sound waves off
the probe are
a) omni-directional
b) a single frequency
c) a range of frequencies
d) non-existent in the dead zone
C
Higher frequency probes are not preferred for inspection of
castings due to
a) poor directivity
b) higher coefficients of transmission
c) higher coefficients of reflection
d) scatter
D
Sound reduction over a distance can be accounted for by
a) absorption
b) scatter
c) beam spreading
d) all of the above
D
Attenuation of ultrasound by absorption is a result of
a) reflection
b) refraction
c) scatter
d) heating
D
For a plane wave, sound pressure is reduced by attenuation in a
_______ fashion.
a) linear
b) exponential
c) random
d) none of the above
B
If a signal on your CRT is 28% FSH and 6 dB gain is added to the
receiver amplifier the signal will be _______ FSH.
a) 34%
b) 42%
c) 56%
d) 70%
C
If a signal is reduced from 84% to 42% FSH, the number of dB
gain removed from the receiver is
a) 2
b) 6
c) 12
d) 42
B
A typical maximum thickness range for inspecting forged steel by
ultrasonics is
a) 0.5 to 1m
b) 1 to 2 m
c) 1 to 10 m
d) 10 to 100 m
C
As temperature of a solid increases the attenuation of sound in
that object tend to
a) increase
b) decrease
c) remain constant
d) vary sinusoidally
A
Scatter is more likely to be a problem if
a) grain size is small
b) grain size is large
c) a material is isotropic
d) grain crystals are cubic
D
Scatter of ultrasound at grain boundaries is a result of
a) frequency
b) in-homogenous inclusions
c) angulation
d) differences in elastic properties
D
Scatter generally increases with
a) increasing grain size
b) decreasing wavelength
c) increasing frequency
d) all of the above
D
In ultrasonic testing a piezoelectric material is used to
a) convert electric energy to mechanical energy
b) convert mechanical energy to electrical energy
c) both a and b
d) none of the above
C
The piezoelectric material first used for ultrasonic transducers
is
a) PZT
b) SiO2 (quartz)
c) Na Cl
d) PVDF
B
X-cut quartz crystal transducers are cut with active element face
at right angles to the
a) X-axis
b) Y1-axis
c) Y2-axis
d) Z-axis
A
Shifts of the positive charge on the silicon and negative charge
on the oxygen in a quartz crystals account for
a) twin crystals
b) the piezoelectric effect
c) polymorphs
d) none of the above
B
In order to generate mechanical displacements (ultrasound waves)
in a X-cut piezoelectric crystal we must
a) squeeze the crystal
b) heat the crystal
c) apply an alternating voltage
d) none of the above
C
Applied voltage on a piezoelectric crystal used in a transducer
requires ________ to cause mechanical displacement
a) electrodes
b) vibration
c) heat
d) all of the above
A
The fundamental frequency of a piezoelectric crystal used in
ultrasonics is a function of
a) its thickness
b) the velocity of sound in the crystal material
c) both a and b
d) none of the above
C
The ratio of vibration amplitude at resonance frequency to the
amplitude of static thickness change is called
a) fo
b) fr
c) the modulus of resonance
d) Q factor
D
A large Q factor indicates
a) high damping
b) narrow bandwidth
c) wide bandwidth
d) low permeability
B
Resonance peaks at frequencies of odd numbered multiples of the
resonance frequency are called
a) harmonics
b) PRF
c) multiple frequencies
d) sub-harmonics
A
In pulse-echo testing there is an advantage to using short pulses
to excite the transducer because
a) the dead zone is decreased
b) the frequency spectrum is broadened
c) both a and b
d) none of the above
C
Of the various materials used for transducer crystals, lithium
sulphate hydrate is the most critical because it
a) looses its water of crystallization above 130 degrees C
b) breaks down at excitation voltages over 500 V
c) cannot be used in immersion testing
d) all of the above
A
A PZT transucer will loose its piezoelectric property if
a) immersed in water
b) used on a forging that has not been de-magnetized
c) used on a surface whose temperature is 140 degrees C
d) heated above its curie point
D
In addition to a low critical temperature, lithium sulphate
hydrate
a) is soluble in water so must be water proofed
b) is a poor impedance match to water
c) has the lowest coupling coefficient
d) none of the above
A
Methods of generating and receiving ultrasound by deformation of
ferromagnetic materials in a magnetic field utilize the
phenomenon called
a) magnetics
b) electrodynamics
c) magnetostriction
d) eddy currents
C
Magnetostrictive principles can be used
a) for transmitting ultrasound
b) for receiving ultrasound
c) both a and b
d) none of the above
C
Mechanical methods of ultrasound generation
a) utilize electro-mechanical hammers
b) utiltize rotating wire brushes
c) require no coupling liquids
d) all of the above
D
The method whereby sound is transmitted through a plate from a
transmitter on one side to a receiver on the other
a) is used to characterize flaws
b) is called an intensity method
c) is used to determine flaw depth
d) all of the above
B
Pulse-echo ultrasonic testing is used for
a) thickness testing
b) flaw detection
c) acoustic velocity determinations
d) all of the above
D
Using the pulse echo method with a 0 degrees probe (single
crystal) on a flat steel plate 50mm thick, the pattern on the CRT
would appear as
a) evenly spaced multiples
b) randomly spaace multiples
c) multiples with increasing spacing between them
d) none of the above
A
When testing thick specimens, it may be advisable to
a) decrease the pulse repetition frequency
b) add reject
c) change to a higher frequency
d) use a delay line probe
A
In immersion testing you would normally position the
a) main bang on the left edge of the CRT
b) entrance echo on the left of the CRT
c) first bacwall on the right edge of the CRT
d) none of the above
B
Transmitter voltage pulse is triggered by the
a) probe resonance
b) control pulse of the sweep generator
c) sweep delay control
d) vertical deflector plates in the CRT
B
For flaws immediately below the surface the best option is
a) TR or twin crystal probes
b) single crystal probes
c) multi probe configurations
d) through wall testing
A
The normal presentation of ultrasonic signals on an ultrasonic
machine used in NDT is
a) rectified form
b) RF form
c) b-scan
d) c-scan
A
If not equipped with a frequency selecter for the reciever
amplifier an ultrasonic machine would probably use a (an)
a) broadband receiver
b) wide receiver
c) ineligible receiver
d) tight end
A
Threshold adjustment is applied to
a) RF display of signals
b) “clean up” the noise on the baseline
c) both a and b
d) none of the above
B
Electrode material on the piezoelectric crystal faces, typically
evaporated to about 1000 angstroms thick, is made of
a) gold
b) silver
c) chrome/gold
d) all of the above can be used
D
Boron, aluminum oxide and sapphire are often used in transducers
as
a) tuning transformers
b) electrodes
c) wear faces
d) none of the above
C
In contact testing using angle beam probes with removable wedges,
the purpose of groves in the front of the wedge is
a) to prevent couplant buildup
b) increase resolution
c) absorb internally reflected sound
d) all of the above
C
The most commonly used wave mode for angle beam testing is
a) longitudinal
b) transverse
c) Rayleigh
d) Lamb
B
Unless otherwise noted, the refracted beam angle on a perspex
wedge is the refracted angle in
a) aluminum
b) brass
c) plastic
d) steel
D
Angle beam wedges can be used to generate surface waves only if
a) the refracted shear wave is 90ø
b) the test piece is steel
c) the test peice is cylindrically shaped
d) none of the above
A
A property of the receiver amplifier that is periodically
verified is
a) horizontal linearity
b) vertical linearity
c) beam spread
d) near zone
B
The purpose of the IIW block is to determine
a) probe exit point
b) refracted angle
c) range (or depth scale)
d) all of the above
D
Information obtained about the exit point and refracted angle of
an angle beam probe
a) is qualitative only
b) must be check periodically since the probe is subject to wear
c) is fixed by the manufacture
d) none of the above
B
The IIW block is used primarily
a) for contact probes
b) for angle beam probes
c) for immersion work
d) in place of the IOW block
A
A system that electronically monitors an echo signal in a gate
such that an alarm is triggered if the signal exceeds a
predetermined amplitude is called a / an
a) B-scan
b) go / no-go system
c) early warning system
d) sweep generator
B
The preferred presentation method for determining the amplitude
of a echo signal is the
a) A-scan
b) B-scan
c) C-scan
d) D-scan
A
Resonance testing methods are used for
a) determining Poisson’s ratio
b) flaw detection
c) thickness testing
d) all of the above
C
Thickness readings from ultrasonic testing can be indicated by
a) reading the position of pips on a CRT screen
b) meter or digital readout
c) graphing by a pen on strip chart paper
d) all of the above
D
For immersion testing, surface scale and rust can be removed by
a) steel brushes and scrapping
b) sand blasting and grinding
c) both a and b
d) none of the above, cleaning is not needed for immersion
testing
C
In contact testing best probe contact is made on ________
surfaces.
a) flat
b) convex
c) concave
d) 250 RMS surfaces
A
Uniformity of coupling is verified by the operator monitoring
a) backwall amplitude
b) “grass” level
c) a and b
d) calibration
C
For normal ultrasonic contact testing of forged carbon steel and
aluminum the optimum frequency range of transducers is
a) 100 to 500 kHz
b) 0.5 to 1 MHz
c) 2 to 5 MHz
d) 10 to 15 MHz
C
High frequency transducers, over 10 MHz, have
a) little use in contact testing
b) very thin crystals
c) good sensitivity to minute defects
d) all of the above
D
When a longitudinal wave is directed along the length of a large
solid shaft from an end of the shaft, sensitivity to defects
fluctuates as the probe is moved from the centre to the outside
edge of the shaft. This is accounted for by
a) interfering edge effects
b) the near zone
c) mode conversion
d) none of the above
A
When performing contact angle beam testing interferring surface
waves can be distinguished from flaws by
a) triangulation
b) testing from the opposite side
c) touching the work surface with an oily finger
d) none of the above
C
When inspecting a thin flat plate with a 60ø shear wave probe it
is possible to see both top and bottom corners of the plate when
the beam is aimed at the plate edge. This is due to
a) ghosting
b) splitting
c) beam spread
d) none of the above
C
When scanning a test plate with angle beam probes, the operator
can often determine the front and backwall position on the screen
from
a) “grass mounds”
b) gates
c) the distance amplitude correction curve
d) none of the above
A
In plate testing with angle beams, the full skip distance refers
to
a) the sound path to the opposite wall
b) twice the sound path to the opposite wall
c) the plate thickness
d) twice the plate thickness
B
For an ultrasound beam to skip in the circumferential direction
of a tubular product
a) the ratio of inside to outside diameter must be right
b) the incident angle must be sufficiently steep
c) both a and b
d) none of the above
C
The delta technique uses
a) a single pulse echo probe
b) a transmitting probe and receiving probe on the same side of
the test piece
c) a transmitting probe and receiving probe on opposite sides of
the test piece
d) there is no such technique
B
Surface wave ultrasonic testing is superior to penetrant testing
because it
a) is cheaper
b) is faster
c) can find sub-surface defects
d) can be used on ferro-magnetic materials
C
Flaw size is often determined by
a) comparison of probe movement with change in amplitude
b) amplitude of maximum reflection
c) both a and b
d) none of the above
C
If the sound beam strikes a flaw at right angles and the flaw has
a greater area than the beam it will
a) cause resonance
b) absorb most of the beam energy
c) cause destructive interference
d) at like a backwall
D
Although ingots of metal are often difficult to test by
ultrasonics due to large dimensions and scatter due to grain
size, it is useful to locate
a) laminations
b) bursts
c) gross piping
d) cold shots
C
Which of the following plate defects would not be a result of
inservice use?
a) stress-corrosion cracking
b) laminations
c) fatigue cracking
d) pitting
B
Production line testing of high pressure ribbed tubing would use
which ultrasonic technique?
a) contact testing
b) immersion testing from the outside diameter
c) immersion testing from the inside diameter
d) the bubbler technique
C
The common metric term Hertz (abb.Hz) is used to indicate
a) wavelength
b) velocity of sound
c) cycles per second
d) acoustic impedance
C
With a sound velocity of 1.5mm/æs in water, the wavelength of the
ultrasonic disturbance in water provided by an ultrasonic
cleaning machines’ 40 kHz transducer is
a) 26mm
b) 26cm
c) 3.7mm
d) 37mm
D
The 3 essential elements common to all systems that use
ultrasonic devices are
a) transducers, cables, couplant
b) transducers, scopes, testpiece
c) power source, transducer, convertor
d) none of the above
C
The incident angle at which the longitudinal mode is refracted at
90ø is
a) 27 degrees
b) the first critical angle
c) the second critical angle
d) not used in NDT
B
The number of nanoseconds in 2 milliseconds is
a) 0.002
b) 2000
c) 2 X 10^6
d) 2 X 10^9
C
When a piezoelectric material has a voltage applied to it
a) eddy currents are generated
b) flux leakage can be used for testing
c) mechnanical deformation occurs
d) all of the above
C
To a degree, the mechanical deformation of a piezoelectric
material is directly proportional to the
a) acoustic impedance of the backing
b) acoustic impedance of the piezo material
c) applied voltage
d) none of the above
C
So as to be utilized as ultrasonic transducers, ferroelectric
ceramics must
a) be heated above their curie point
b) poled
c) be put into an electric field
d) all of the above
D
Most piezoelectric ceramics (ferroelectrics) are
a) polycrystalline
b) also ferromagnetic
c) statically charged
d) are better receivers than transmitters
A
When ferro electric ceramics such as PZT are heated to above
their curie point and held under a bias voltage while cooling to
80øC they are considered
a) neutralized
b) annealed
c) poled or polarized
d) charged
C
When using quartz as a piezoelectric transducer, longitudinal
waves are generated from the
a) X - cut
b) Y - cut
c) Z - cut
d) GT - cut
A
The advantage of quartz crystals over ceramic materials for
ultrasonic transducers is
a) high curie temperature
b) its harness and ability to take a high polish
c) both a and b
d) there are no advantages of quartz over ceramics
C
Although quartz has about twice the receiving sensitivity of PZT,
PZT used for pulse-echo testing in NDT results in higher
amplitude signals for the same conditions because
a) transmission constant is higher
b) PZT dielectric constant is lower
c) PZT has a lower density
d) all of the above
A
Lithium sulphate as a transducer material is most notable for
its
a) high curie point
b) low coupling coefficient
c) high solubility in water
d) none of the above, lithium sulphate is not used as a
transducer material
C
A positive valve of a reflection coefficient indicates
a) no phase change has occurred
b) 90 degree phase change
c) 180 degree phase change
d) an increase in amplitude
A
A negative value of a reflection coefficient indicates
a) no phase change has occured
b) 90ø phase change
c) 180ø phase change
d) a decrease in amplitude
C
The purpose of highly absorptive backing material in transducers
used for testing is to
a) eliminate sound re-entering the crystal
b) maximize rise time
c) maximize fall time
d) obtain highest resolution by broadening the frequency
bandwidth
A
Short highly damped pulses of ultrasound have their advantage in
NDT in that
a) sensitivity is increased
b) time measurement accuracy is improved
c) defect characterizations is simplified
d) all of the above
B
A material that exhibits dimensional changes in a magnetic field
is said to be
a) electrostrictive
b) ferroelectric
c) magnetostrictive
d) electromagnetic
C
Which of the following is not a magnetostrictive material
a) cobalt
b) PZT
c) nickel
d) iron
B
The advantage of magnetrostrictive transducers is
a) sturdiness
b) resistance to damage under adverse conditions
c) ability to be constructed in very large sizes
d) all of the above
D
Standing waves in any medium are result of
a) interference from reflections
b) the PRF
c) wave splitting
d) mode conversion at boundaries
A
An acoustic lens for focusing ultrasound at a specific point in
front of the transducer is made as thin as possible so as to
a) make the probe as light as possible
b) obtain the shortest focal length
c) minimize absorption
d) all of the above
C
Focusing of ultrasound energy is accomplished by
a) lenses
b) shaping ceramic transducers
c) test piece geometry
d) all of the above
D
The purpose applying ultrasound to a weld puddle during electric
arc welding is to
a) prevent lack of penetration
b) increase heat in the weld puddle
c) create a finer grain structure and increase tensile strength
d) eliminate the requirement for radiographic testing
C
Ultrasonics used for drilling or machining has the advantage
that
a) no cutting fluids are required
b) complex shapes can be cut out in a single pass
c) the workpiece does not heat up locally
d) all of the above
B
If a 1 MHz quartz crystal (cut for half-wave resonance) is 0.29
cm thick, how thick would it have to be if the half-wave
resonance frequency was to be 10 MHz?
a) 0.29 mm
b) 2.9 mm
c) 2.9 cm
d) 5.8 microns
A
Using the through transmission method of ultrasonic testing
a) no couplant is needed
b) no flaw echo is seen
c) only one transducer is used
d) fillet welds are best tested
B
The advantage of a longer path length in the standard perspex
wedge of a common contact-angle beam transducer is
a) improved near surface resolution
b) better impedance matching
c) higher sensitivity to small defects
d) all of the above
A
Increased damping on a piezoelectric element results in
a) reduced ringing time
b) increased resolution
c) decreased sensitivity
d) all of the above
D
You are given a cube of material 20mm thick. By pulse-echo
immersion testing you determine the multiples of this material to
be separated by 6.9 microseconds, the longitudinal velocity of
sound in the material is
a) 1500 m/s
b) 3450 m/s
c) 5800 m/s
d) 6900 m/s
C
Given a cube of iron (long. velocity = 5800 m/s), pulse-echo
multiples are seen every 100 microseconds. What is the thickness
of the iron?
a) 100 mm
b) 29 mm
c) 29 cm
d) 58 cm
C
The difference between a thickness gauge and a distance gauge is
a) the range that is measured
b) velocities involved
c) type of piezoelements used
d) all of the above
A
The incremental fine gain control of the ultrasonic instrument is
calibrated in
a) 1 or 2 dB increments
b) 6 dB increments
c) 20 dB increments
d) no increments, it is completely variable
A
“Delay” on the ultrasonic machine is used to
a) reduce grass level
b) compensate for range errors
c) correct for proper zero point
d) adjust lag on the pulser
C
Most codes would recommend the actual beam angle of an angle beam
probe not deviate from the indicated angle by more than
a) one half degree
b) one degree
c) two degrees
d) five degrees
C
When performing contact weld inspection the purpose of doing a
normal beam inspection of the parent metal adjacent to the weld
is
a) to establish material thickness
b) to locate laminations or other impeding inclusions
c) to note variations in attenuation
d) all of the above
D
The best way to determine the required sensitivity for ultrasonic
testing is
a) to use 20 dB over the gain needed to put the 1.5 mm diameter
hole of the IIW block to 80% FSH
b) use enough gain to get “10% grass” from the opposite wall
c) use reference welds with real defects of the minimum
acceptable size
d) from flat bottom hole and side drilled hole response studies
C
Which of the following is not a consideration when choosing a
couplant for ultrasonic testing
a) type of material tested
b) surface finish of test piece
c) orientation of test surface
d) nominal test frequency
D
In weld inspection, the longitudinal wave inspection of the plate
adjacent to the weld is usually done using a frequency in the
range of
a) 1-2 MHz
b) 2-6 MHz
c) 6-10 MHz
d) 10-15 MHz
B
The size and shape of ultrasonic probes used are determined
primarily by
a) the level II operator
b) the specific application
c) expected defect type and orientation
d) whether contact or immersion methods are used
B
Attenuation is not a result of
a) beam geometry
b) scatter
c) bond breaking at the molecular level
d) absorption
A
Probe index, refracted angle, timebase and sensitivity are
usually calibrated using
a) calibrator electronics
b) tuning forks
c) calibration and or reference blocks
d) the test piece itself
C
When using angle beams (transverse waves) for ultrasonic testing,
the position of a flaw signal on the timebase can be calibrated
for
a) sound path length
b) stand-off distance
c) depth of defect
d) all of the above
D
Which is not a commonly used target when establishing sensitivity
for ultrasonic testing?
a) side drilled holes
b) a tungsten ball
c) the 100 mm quadrant of the IIW block
d) flat bottom holes
B
The gain required to compensate for differences in coupling
efficiency between a reference or calibration block and the work
piece is called
a) transfer correction or transfer value
b) absorption coefficient
c) scatter modulus
d) attenuation constant
A
The purpose of moving a contact angle beam probe back and forth
perpendicular to the axis of the weld inspected is to
a) evaluate defects
b) eliminate the need for scanning from 2 sides
c) ensure full volumetric inspection of weld and heat affected
zone
d) practice echo-dynamics
C
In weld inspection, transverse cracks are best located by
a) scanning at right angles to the weld axis
b) scanning parallel to the weld axis
c) the lamination scan
d) immersion testing
B
The recommended refracted angle for contact shear wave inspection
of plate less than 10mm thick is
a) 45ø
b) 60ø
c) 70ø
d) all of the above
C
The position of a defect found by an angle beam inspection
requires that you know
a) the refracted angle and exit point
b) sound path distance
c) geometry and dimensions of the test piece
d) all of the above must be known
D
The length of a defect is calculated from
a) DGS diagrams
b) lateral probe movement
c) amplitude
d) horizontal displacement of the signal on the timebase
B
Manual probe movement in contact scanning to evaluate a defect
for type is
a) in the lateral direction
b) in a transversing direction
c) both orbital and rotational
d) always a combination of all of the above
D
To improve the accuracy of defect location and evaluation you
should
a) reduce gain
b) increase range
c) check calibration
d) use a probe of higher frequency
D
Amplitude response of a defect is not influenced by
a) equipment settings and probe characteristics
b) attenuation
c) defect location and orientation
d) none of the above
D
Maximum amplitude response of a planar defect will usually be had
when
a) its main surface is perpendicular to the sound beam
b) its main surface is parallel to the sound beam
c) its main surface is oblique to the sound beam
d) none of the above, amplitude will be about equal for a given
flaw regardless of orientation
A
Reference reflectors in calibration blocks are normally
cylindrical holes because
a) they are easier to machine
b) they best represent actual defects
c) they are not as directionally dependant
d) none of the above
C
When drawing a distance/amplitude curve (DAC) you set the signal
from the reference hole which gives the maximum amplitude to
a) 100% full screen height (FSH)
b) 80% - 90% FSH
c) 50% FSH
d) 12 dB over the response from the 7/8 node
B
When contact testing is performed, a transfer value is
a) used to compensate for attenuation
b) used to compensate for variations in coupling
c) both a and b
d) not used
C
If the beam from an unfocused probe strikes a convex steel
surface from water with normal incidence it will
a) increase beam spread
b) decrease beam spread
c) focus the beam
d) none of the above
A
If the beam from an unfocused probe strikes a concave steel
surface with normal incidence from water it will
a) increase beam width
b) decrease beam width
c) be totally converted to surface waves
d) none of the above
B
Severity of a defect is determined by
a) amplitude of signal relative to reference
b) length of flaw
c) type and orientation of flaw
d) all of the above
D
The result of a rough test surface in ultrasonic testing is
a) reduced acoustic coupling
b) beam distortion
c) to change the wavelength of sound in the test piece
d) both a and b
D
The effect of increasing the temperature of a test piece to 30
degrees C. is to
a) improve acoustic coupling
b) decrease resolution
c) require high temperature couplant
d) decrease acoustic velocity
D
The ability to separate individual defects lying closely together
is called
a) sensitivity
b) resolution
c) angular acuity
d) linearity
B
A calibration block can be used to
a) check instrument and probe characteristics
b) set sensitivity for inspection
c) reproduce previously used settings
d) all of the above
D
When establishing the relative sensitivity of higher power
longitudinal wave probes on the methyl polymethacrylate insert of
the IIW block
a) the total number of echoes is noted
b) the amplitude of the last echo is noted
c) the gain setting is noted
d) both a) & b)
D
When using the IIW Block #1, the probe exit point is established
using the
a) 1.5mm diameter hole
b) 100mm radius
c) 50mm diameter hole
d) perspex insert
B
When calibrating for an inspection range of 0 to 100mm with an
angle beam probe, delay on the instrument must be
a) increased
b) decreased
c) left untouched
d) adjusted to correct for the time delay in the perspex wedge
D
The main advantage of the Rompas or DIN block (IIW block 2) is
a) increased number of characteristics that can be tested
b) greater ranges can be tested
c) improved sensitivity calibrations
d) portability
D
When using the large IIW Block #1, what are the fewest number of
reflections you would need to use to calibrate a longitudinal
probe for 100mm range?
a) 1
b) 2
c) 4
d) 8
B
When using the large IIW Block #1, what are the fewest number of
reflections from the 100mm radius in order to calibrate a 70
degree shear wave probe for a 100mm range?
a) 1
b) 2
c) 2 1/2
d) 3
B
The use of flat bottom holes for a reference standard when
testing forgings is a reasonable method of flaw assessment
because
a) they provide good reflectivity at all angles
b) of their ease of manufacturing
c) a single block is required for all calibrations
d) they are a good representation of the flat defects found in
forgings
D
Flat bottom hole test blocks are made
a) of the same alloy as the test piece
b) with varying depth from the test surface to compare response
at different distances from the probe
c) with different target sizes to establish reflection equality
between a flaw and a standard
d) all of the above
D
Maximum sensitivity of a transducer is found at the
a) probe surface
b) test surface
c) end of the near zone
d) end of the dead zone
C
A flat normal beam probe has a near zone of 25mm in water. If
used in direct contact on steel the near zone would be
a) 3mm
b) 6mm
c) 8mm
d) 12mm
B
Attenuation of ultrasonic energy is an inherent property of all
materials and is
a) a constant 0.5 dB/cm
b) variable with alloy and test frequency
c) a function of acoustic impedance
d) both b and c
B
A focused probe is positioned in water 5 cm over a plate 10cm
thick. The probe having a focal length of 6 cm will focus
a) 1 cm above the plate
b) 0.25 cm from the entry surface of the plate
c) 0.25 cm from the back surface of the plate
d) 0.4 cm into the water on the opposite side of the plate
B
In ultrasonic testing the term sensitivity usually refers to the
test system’s ability to discern
a) small distances between defects
b) the angular separation between defects
c) the smallest size defect
d) none of the above
C
When performing a pulse-echo test, if you scanned over a large
defect with the same acoustic impedance as the material you were
testing
a) maximum response would occur only at right angles
b) the AVG (DGS) method would be used for sizing
c) it would not be detected
d) detection would depend on how much gain over reference you
were scanning with
C
Modern ultrasonics uses signal processing methods like signal
averaging, spectral analysis, deconvolution auto-correlation and
filtering to
a) increase scanning speeds of automated systems
b) eliminate ultrasonic operators
c) provide smoother looking A-scans
d) both locate and characterize flaws
D
In ultrasonic spectrum analysis, the effect of increasing metal
grain size on the spectra would be
a) reduction in lower frequencies
b) reduction in higher frequencies
c) an increase in frequencies at the corresponding grain size
d) none of the above
B
When trying to obtain a “noise free” signal a filter is sometimes
used. If this filter limits signals to just a narrow range of
frequencies it is called a _________ filter.
a) low-pass
b) high-pass
c) band-pass
d) broadpass
C
In ultrasonic testing, one of the best means of conveying a large
quantity of information about a test piece is by
a) B-scans
b) C-scans
c) ultrasonic imaging
d) the tandem probe technique
C
Acoustic imaging techniques permit the visualization of objects
because
a) sound can be converted to light when passing through metal
b) of the polarity of transverse waves
c) sonoluminescence occurs in couplant
d) acoustic waves obey the same equations as optical waves
D
Ultrasonic waves with frequencies of 400MHz to 2GHz would be used
in
a) acoustical microscopy
b) concrete testing
c) ultrasonic cleaning
d) nothing, it is not possible to generate ultrasound in this
range
A
If the “focal spot” size of the beam from a focused transducer
was increased by increasing the focal length
a) sensitivity would increase
b) resolution would decrease
c) all flaws would be detected
d) no indications would be rejectable
B
In nondestructive testing the acronym EMAT stands for
a) electromagnetic acoustic transducer
b) electrically metered automatic testing
c) energy modulated acoustic technique
d) engineers make assessment tough
A
When performing contact ultrasonic testing, significant amplitude
variations from the same indication can result from
a) transducer angle
b) couplant thickness
c) probe wear face thickness
d) all of the above
D
The advantage of a short duration excitation pulse applied to a
normal transducer is
a) wideband frequency operation
b) high resolution
c) reduced attenuation loses
d) all of the above
D
Generally, longitudinal waves propagate__________.
a) faster than shear waves
b) slower than shear waves
c) at right angles to shear waves
d) parallel to shear waves
A
For a single crystal piezoelectric material used in an ultrasonic
transducer the angle to the crystal axis that it is cut
determines
a) frequency
b) direction of deformation
c) Q-factor
d) both a and b
B
Alignment of the small domains in polycrystalline ferro-electric
materials, such as PZT, is called
a) poling
b) polarisation
c) both a and b
d) domaining
C
In a ferroelectric ceramic such as PZT, the curie temperature is
the temperature above which
a) the piezoelectric domain structure is lost
b) water is driven out of the crystal
c) polarity reverses
d) electrodes cannot be deposited
A
In some ultrasonic probe arrangements, one variety of piezo
material is used for the transmitter and another for the
receiver. The purpose of two different materials is
a) to make fabrication of the probe easier
b) to take advantage of broadband receivers
c) to optimise relative efficiencies of transmitter and receiver
elements
d) all of the above
C
The parallel of mechanical resonance frequency of a piezoelectric
element occurs when the element thickness is
a) one quarter wavelength
b) one half wavelength
c) one wavelength
d) none of the above
B
Backing materials used in ultrasonic transducers are used for
a) changing frequency bandwidths
b) focusing the beam
c) de-focusing the beam
d) none of the above
A
The purpose of putting one or more matching layers between the
front face of a probe and the coupling medium is
a) to decrease ringing time
b) to improve coupling
c) to provide a delay line effect
d) not known by probe manufacturers
B
The result of spherical or “cup shaped” lens on the front of an
ultrasonic probe is a(n)
a) point focused beam
b) line focused beam
c) asymptotic beam
d) divergent beam
A
Variations in a probes’ actual frequency and its nominal
frequency by as much as 5%
a) put the probe “out of spec”
b) have significant effects on test results
c) are acceptable in NDT
d) none of the above
C
Electromagnetic acoustic transducers (EMATs) are made from
a) silicon chips
b) ferro-magnetic crystals
c) ferro-electric crystals
d) coils of wire
D
Mechanical deformation of a material placed in a magnetic field
is called
a) magnetostriction
b) warp factor
c) reverse piezoelectric effect
d) undulation
A
The most common single measurement made on ultrasonic transducers
is determination of
a) nature of sound field
b) bandwidth
c) actual centre frequency
d) none of the above
A
Velocity of ultrasonic waves in steel at 10øC. as compared to
40øC. are
a) slower
b) faster
c) the same
d) dependant on the alloy of steel maybe faster or slower
B
Using an unrectified A-scan presentation the dominant frequency
can be determined provided you know the
a) sound path to the reference reflector
b) nominal probe frequency
c) time interval on the baseline
d) none of the above
C
Pulse length determines a probes’
a) frequency
b) acoustic impedance
c) damping
d) depth resolution
D
The purpose of determining signal-to-noise ratio is
a) to verify good coupling
b) necessary to ensure small flaws do not go undetected
c) a check on the accuracy of the attenuator
d) a check on the sensitivity afforded by uncalibrated gain
B
Another term for the suppression control on an ultrasonic machine
is
a) reject
b) damping
c) attenuation
d) gain
A
Probes used in ultrasonic contact testing are checked
periodically for performance when in regular use. Which
characteristic would not be checked daily?
a) probe index
b) beam angle
c) beam profile
d) overall system gain
C
A deviation in actual refracted angle of + or - 2 degrees will
result in
a) errors in depth calculations
b) errors in stand-off calculations
c) errors in sound path calculations
d) both a and b
D
When using perspex wedges for contact testing, if the actual
refracted angle varies by more than + or - 2 degrees the wedge
should be
a) replaced
b) re-ground
c) re-calibrated
d) a or b
D
The method of non-destructive testing which uses acoustic energy
usually in the 1MHz to 5 MHz range is
a) sub-sonic testing
b) ultrasonic testing
c) E-M testing
d) acoustic flux leakage testing
B
The testing of materials to detect internal, surface and
concealed defects or discontinuities by methods which do not
damage or destroy the material under test is called
a) surveillance testing
b) electromagnetic testing
c) acoustic testing
d) non-destructive testing
D
In ultrasonic testing, the display in which pulse amplitude is
represented as a displacement along one axis and time as a
displacement along the other axis is called a(n)
a) A-scan
b) B-scan
c) C-scan
d) isometric display
A
The product of density an acoustic velocity is
a) acoustic impedance
b) electric impedance
c) specific reactivity
d) the reflection coefficient
A
The number of oscillations per second experienced by a particle
as an acoustic wave passes through it is called the
a) wavelength of the oscillation
b) acoustic frequency
c) period of oscillation
d) none of the above
B
The angle at which an ultrasonic beam spreads in the far zone is
called the
a) wave angle
b) phase angle
c) angle of repose
d) angle of divergence
D
A contact probe which introduces an ultrasonic wave into a test
piece so that the beam angle in the test piece is a some angle
other than 0 or 90 degrees to the normal is called a(n)
a) angle probe or angle beam probe
b) shear wave probe
c) dry coupling probe
d) Rayleigh probe
A
The control on an ultrasonic machine which enables electrical
signals to be decreased by known values, usually dB, is called
a(n)
a) attenuator
b) matching box
c) reject control
d) damping control
A
The line of maximum sound intensity in the far zone of an
ultrasonic beam, and its projection back to the near zone is
called the
a) half angle of divergence
b) beam spread
c) beam profile
d) beam axis
D
In ultrasonic testing, the distance travelled along the beam axis
is called
a) beam path length
b) stand-off
c) corrected distance
d) none of the above
A
A compression wave probe is used to generate and/or receive
a) longitudinal waves
b) shear waves
c) Rayleigh waves
d) Lamb waves
A
Material attached to the rear of an ultrasonic crystal to
increase damping is called
a) tuning material
b) matching
c) crystal backing
d) none of the above
C
A presentation where-by the relative amplitude of ideal
reflectors of different sizes are plotted against different
distances is called
a) DGS diagrams
b) AVG diagrams
c) DAC curves
d) both a and b
D
The dominant frequency of an ultrasonic flaw detection system
depends on the
a) probe
b) machine receiver and amplifier
c) pulse propagation path
d) all of the above
D
A probe constructed such that the ultrasonic waves converge at a
point or line is a(n)
a) dual crystal probe
b) focused probe
c) de-focused probe
d) immersion probe
B
The amount by which the electrical signal from the ultrasonic
transducer is amplified is
a) the gain
b) signal-to-noise ratio
c) 6
d) none of the above
A
Gain and attenuator controls on an ultrasonic machine are usually
calibrated in
a) arbitrary units
b) volts
c) decibels
d) none of the above
C
A probe specially designed to be used totally under water is
called a(n) _________ probe.
a) immersion
b) bubbler
c) gap
d) contact
A
Background indications seen on an A-scan, arising from material
characteristics and/or electrical noise is termed
a) grass
b) interference
c) pick-up
d) hash
A
The method whereby the test piece is either wholly or partially
under water or other such coupling fluid is called
a) gap testing
b) jet testing
c) plate testing
d) immersion testing
D
In an A-scan presentation, the indication of the instant at which
the pulse is applied to the transmitting crystal is the ________
indication.
a) initial pulse
b) threshold
c) R-F
d) sweep
A
The phenomenon whereby a longitudinal wave generates waves of
other modes upon reflection or refraction is
a) total internal reflection
b) mode conversion
c) conversion mechanics
d) none of the above
B
Acoustic or electrical interference in ultrasonic testing is
often called
a) baseline
b) noise
c) ghost echo
d) over attenuation
B
The short wave-train produced on each excitation of an ultrasonic
transducer is a(n)
a) acoustic tone burst
b) half-wave
c) pulse
d) surface acoustic wave
C
An echo received from a reflector of known size and
characteristics could be termed a
a) reference echo
b) spurious echo
c) ghost echo
d) solid echo
A
Spreading the timebase interval to enable signals from a selected
range to be displayed is called
a) magnification
b) delay
c) scale expansion
d) decompression
C
The distance between successive points of impingement of the beam
axis on the entry surface after reflecting from the opposite side
is called
a) stand-off
b) skip distance
c) sound path
d) none of the above
B
The display generated so that distance along a horizontal axis is
proportional to time is a(n)
a) time base
b) C-scan
c) unrectified display
d) none of the above
A
The imaginary line that connects all the points of the same phase
in a wave propagating in a medium is referred to as the
a) phase line
b) wave front
c) interphase index
d) refractive index
B
The plastic prism coupled between and ultrasonic transducer and a
test piece which causes the ultrasonic waves to propagate at a
known angle within the test piece is called a
a) wedge
b) solid couplant
c) variable angle adapter
d) none of the above
A
Which of the following methods would not use pulsed ultrasound?
a) pulse-echo
b) pitch-catch
c) through-transmissions
d) all of the above would use pulse ultrasound
D
When using the “pitch-catch” method of ultrasonic testing, which
is not true?
a) two piezoelectric elements are commonly used
b) all the piezoelements are mounted in one housing
c) both shear and longitudinal modes can be used
d) one element is dedicated to transmission
B
Sizing of defects located in the near zone is difficult because
of
a) uncertainties of sound pressure along the beam axis
b) uncertainties of sound pressure at right angles to the beam
axis
c) frequency variation
d) both a and b
D
A rough surface may affect resolution and sensitivity by
a) increasing scatter
b) causing unwanted mode conversions
c) decreasing coupling
d) all of the above
D
Maximum acoustic energy is coupled from one medium to another
when the acoustic impedance of the first medium is _________ the
second.
a) less than
b) greater than
c) the same as
d) twice the value of
C
Which of the following terms is not used to describe methods of
coupling ultrasonic energy into a test specimen?
a) non-invasive
b) direct contact
c) immersion
d) gap
A
In immersion testing, the hindrance of multiple interface signals
that results from the pulse bouncing between the test piece and
probe on normal incidence is avoided by
a) decreasing receiver gain
b) increasing the distance between probe and work surface
c) increasing damping
d) use of the interface-lock feature
B
Which mode of wave used in nondestructive testing is not
initially produced by mode conversion?
a) longitudinal
b) shear
c) transverse
d) Rayleligh
A
Resonance methods of thickness testing are no longer commonly
used. This technique utilized
a) continuous wave oscillators
b) pulsed wave packets
c) surface waves
d) none of the above
A
To avoid distortion of received ultrasonic signals the receiver
amplifier should have similar bandwidth characteristics as the
a) test piece resonant frequency
b) receiving transducer
c) transmitting transducer
d) none of the above, receiver bandwidth is not important
B
Transducers with high-Q factor have
a) broadband-type pulses
b) poor penetrating ability
c) poor resolution compared to low-Q factor
d) all of the above
C
In hardcopy presentations of C-scans, the item recorded is
a) a absence of signal
b) the presence of a signal
c) the depth of a signal
d) a or b
D
If you wanted to determine the depth a large surface breaking
crack extending into a plate you were inspecting using an angle
beam, you would need to know
a) soundpath distance
b) actual refracted angle
c) total forward/backward travel of the probe
d) all of the above
D
Significant advantage of ultrasonics over radiography is
a) it is safe
b) it can be used on ferrous and non-ferrous metals
c) all defects in any piece can be located
d) the ability to use it underwater
A
Which is not a characteristic of ultrasound used to evaluate
materials
a) attenuation
b) density
c) magnitude of echoes
d) velocity
B
In ultrasonic testing, attenuation studies are
a) used to study some properties of materials
b) used only in destructive tests
c) only useful when using longitudinal wave mode
d) never used
A
Surface wave testing would be used to detect
a) lamination in 10mm thick plate
b) microshrinkage in magnesium castings
c) slag inclusions in submerged arc welds
d) fatigue cracks in helicopter blades
D
The most common method of ultrasonic testing of welds is
a) continuous wave resonance
b) normal beam
c) angle beam
d) through-transmission
C
Which is not a welding defect term
a) porosity
b) slag
c) lamination
d) hot cracking
C
The orientation of the defect with respect to the direction of
the ultrasonic beam determines
a) whether the reflected pulse returns to the receiver
b) if immersion or contact testing is used
c) if immersion or gap testing is used
d) none of the above
A
To inspect tubular products using the ultrasonic method,
a) longitudinal wave mode is used
b) shear wave mode is used
c) surface wave mode is used
d) all wave modes can be used
D
Production line ultrasonic inspection of tubular test pieces is
done by
a) immersion methods
b) gap methods
c) contact testing methods
d) any of the above can be used depending on the specifics of the
application
D
Tubing ie. tubular products, is best inspected by ultrasonics
using the __________ method.
a) pulse-echo
b) transmit-receive
c) induction coil
d) time of flight diffraction
A
Thickness measurements of plates are made using ______ waves.
a) Rayleigh
b) shear
c) compressional
d) Lamb
C
The purpose of water jets in ultrasonic inspection of hot plate
(100øC.) is
a) to provide a coupling medium
b) to keep the probe cool
c) both a and b
d) none of the above
C
The principles involved in testing non-metals by ultrasonics as
compared to metals are
a) significantly different with regards to coupling only
b) simpler because shear waves are not involved
c) more complex due to birefringence
d) essentially the same
D
Ultrasonic testing of concrete would be carried out using
frequencies in the range of
a) 100 to 500 Hz
b) 25 to 100 kHz
c) 0.5 to 1 MHz
d) 2 to 4 MHz
B
Rubber tires can be inspected by ultrasonic means but it requires
lower frequencies in the range of 50 kHz because
a) high frequencies delaminate the rubber
b) high frequencies uncure the rubber
c) of attenuation from scatter off the fibres
d) none of the above
C
Ultrasonic pulse-echo techniques are used on livestock to
a) establish fat profiles
b) modify behaviour
c) increase reproductive capability
d) all of the above
A
Ultrasonics has been applied in
a) fish finders and measuring water depths
b) volume, channel and colour control of televisions
c) auto-focusing mechanisms in cameras
d) all of the above
D
Given a 10 MHz probe vibrating into water, with a velocity of 1.5
mm/æs, what is the wavelength of the longitudinal wave
a) 0.15 mm
b) 1.5 mm
c) 1.5 cm
d) 0.6 cm
A
Given a 2.5 MHz transducer radiating ultrasound into glycerin,
what is the wavelength of the shearwave in the glycerin?
a) 2.3 mm
b) 3.2 mm
c) insufficient information provided
d) none of the above
D
Given a 2 MHz PZT crystal coupled to steel at an angle of
incidence of 3ø, what is the wavelength of the shearwave in steel
if V long is 5.9mm/æs and V shear is 3.2mm/æs?
a) 0.63 mm
b) 1.6 mm
c) 6.4 mm
d) a shear wave will not be present
B
Given a 4 MHz probe radiating normally into copper, V long = 4.7
km/s V shear = 2.3km/s, the wavelength of the longitudinal wave
is
a) 0.85mm
b) 1.18 mm
c) 2.36mm
d) 2.99mm
B
A plane longitudinal wave strikes a water-steel interface from
water ( V long water=1.5Km/s V long steel= 5.9km/s V shear
steel=3.2km/s ) at normal incidence. Having had a 2mm wavelength
in water it will result in the shear wave wavelength being
a) 2.6mm
b) 1.5mm
c) 0.8 mm
d) none of the above, a shear wave does not occur
D
The probe movement that maintains a constant distance from an
indication while varying the direction of the beam is called
a) orbiting
b) pivoting
c) traversing
d) lateral movement
A
The indication on the instrument display
that represents the far boundary of the
material being tested is called:
a. hash
b. the initial pause
c. the main bang
d. the back surface reflection
D
Another name for a compressional wave
IS:
a. lamb wave
b. shear wave
c. longitudinal wave
d. transverse wave
C
In immersion testing, the position of the
transducer is often varied to transmit
sound into the test part at various angles
to the front surface. Such a procedure is
referred to as:
a. angulation
b. dispersion
c. reflection testing
d. refraction
A
Another name for rayleigh waves is:
a. shear waves
b. longitudinal waves
c. transverse waves
d. surface waves
D
The cable that connects the ultrasonic
instrument to the transducer is specially
designed so that one conductor is
centered inside another. The technical
name for such a cable is:
a. BX cable
b. conduit
c. coaxial cable
d. ultrasonic conductor cable-grade 20
C
A material used between the face of a
transducer and the test surface to permit
or improve the transmission of ultrasonic
vibrations from the transducer to the
material being tested is called:
a. a wetting agent
b. a couplant
c. an acoustic transmitter
d. a lubricant
B
The process of standardizing an
instrument or device by using a reference
a standard is called:
a. angulation
b. calibration
c. attenuation
d. correlation
B
The piezoelectric material in a transducer
that vibrates to produce ultrasonic waves
is called a:
a. backing material
b. Lucite?’ wedge
c. crystal
d. couplant
C
Ultrasonic testing of material where the
probe is in direct contact with the
material being tested may be:
a. straight beam testing
b. surface wave testing
c. angle beam testing
d. all of the above
D
An advantage of using lithium sulfate in
transducers is that it:
a. is one of the most efficient generators
of ultrasonic energy
b. is one of the most efficient receivers of
ultrasonic energy
c. is insoluble
d. can withstand temperatures as high as
700°C (1 260 OF)
B
The transducer that contains the thinnest
piezoelectric crystal is a:
a. 1MHz transducer
b. 5 MHz transducer
c. 15 MHz transducer
d. 25 MHz transducer
D
A 25 MHz transducer would most likely
be used during:
a. straight beam contact testing
b. immersion testing
c. angle beam contact testing
d. surface wave contact testing
B
The amount of beam divergence from a
crystal is primarily dependent on the:
a. type of test
b. tightness of crystal backing in the
transducer
c. frequency and crystal size
d. pulse length
C
When an ultrasonic beam passes through
the interface between two dissimilar
materials at an angle, a new angle of
sound travel takes place in the second
material due to:
a. attenuation
b. rarefaction
c. compression
d. refraction
D
The transducer shown in Figure 1 is used
for:
a. surface wave testing
b. angle beam testing
c. immersion testing
d. straight beam testing
D
Figure 2 illustrates a contact test on an
203 mm (8 in.) aluminum block. A
discontinuity is located 152 mm (6 in.)
from the front surface. The display
representation for this is shown to the
right. What does indication A represent?
a. the initial pulse or front surface
indication
b. the first discontinuity indication
c. the first back surface reflection
d. none of the above
A
In Figure 2, indication B represents:
a. the initial pulse or front surface
indication
b. the first discontinuity indication
c. the first back surface reflection
d. none of the above
A
In Figure 2, indication C represents the:
a. second back surface reflection
b. first discontinuity indication
c. second discontinuity indication
d. first back surface reflection
C
D
In Figure 2, indication D represents the:
a. first discontinuity indication
b. second indication of the discontinuity
c. first back surface reflection
d. second back surface reflection
C.204;
B
In Figure 2, indication E represents the:
a. first discontinuity indication
b. second discontinuity indication
c. first back surface reflection
d. second back surface reflection
D
The velocity of longitudinal waves is
approximately the velocity of
shear waves in the same material.
a. two times
b. four times
c. 1/2
d. 9/10
A
Figure 3 illustrates an immersion test of a
76 mm (3 in.) block of aluminum with a
discontinuity located 51 mm (2 in.)
below the surface. The display pattern is
shown also. What does indication A
represent? Assume no sweep delay is
used.
a. the first front surface indication
b. the initial pulse
c. the first discontinuity indication
d. the first back surface reflection
B
In Figure 3, indication B represents the:
a. first front surface indication
b. initial pulse
c. first back surface reflection
d. first discontinuity reflection
A
In Figure 3, indication C represents the:
a. first front surface indication
b. first discontinuity indication
c. first back surface reflection
d. second front surface indication
B
In Figure 3, indication D represents the:
a. first discontinuity indication
b. first back surface reflection
c. second front surface indication
d. second discontinuity indication
B
In Figure 3, the distance between
indications A and B represents:
a. the distance from the front surface of
the aluminum block to the
discontinuity
b. the distance from the front surface of
the aluminum block to the back
surface of the aluminum block
c. the water distance from the
transducer to the aluminum block
d. none of the above
C
Under most circumstances, which of the
following frequencies would result in the
best resolving power?
a. 1MHz
b. 5 MHz
c. 10 MHz
d. 25 MHz
D
Which of the following materials of the
same alloy is most likely to produce the
greatest amount of sound attenuation
over a given distance?
a. a hand forging
b. a coarse-grained casting
c. an extrusion
d. the attenuation is equal in all
materials
B
In contact testing, the entry surface
indication is sometimes referred to as:
a. the initial pulse
b. the back reflection
c. the skip distance
d. the scan path
A
