Ultrasonic Testing
Area amplitude blocks have hole diameters of 1/64 inch through 8/64 inch. The No. __________ block has a 5/64-inch-diameter hole.
5
The typical CRT screen display of the pulse-echo instrument is an ____________ scan.
A
When high-speed automatic scanning is used, a permanent record of the test can be made with a(an) ___________-scan recording.
A, B, or C
The presentation using a time versus amplitude CRT display is known as _____________.
A-scan
The ____________ block is specified by the American Society of Mechanical Engineers and is used in their Boiler and Pressure Vessel Code for calibration.
ASME
The velocities for the various wave modes in materials can be found in tables that normally also list the ____________ of materials.
Acoustic Properties
The ultrasonic characteristic of a medium defined by the product of density and velocity is:
Acoustical Impedance
In a set of area amplitude blocks, the sound-path distances are all:
Alike
The alarm sensitivity control is used to set the indication ____________ at which the alarm, recorder or process feedback will be triggered.
Amplitude
The reject control is used to eliminate very low ____________ indications along the sweep.
Amplitude
Transducer sensitivity is measured by the ______________ of its response, as displayed on the CRT screen, fro an artificial discontinuity in a standard reference block.
Amplitude
Ultrasonic waves reflected from an angular surface may result in a reduction or complete loss of indication:
Amplitude
A transducer will produce (and receive) a band of frequencies near its central frequency _____________. This band of frequencies is known as the _____________.
Amplitude, Bandwidth
In contact testing, ____________ transducers are used to find or evaluate discontinuities orientated other than parallel to the specimen's surface.
Angle Beam
The angle at which an incident beam strikes the interface is the angle of:
Angulated
A couplant must be easy to _____________ and easy to _____________ but still have a tendency to __________ on the surface.
Apply, Remove, Stay
Shear wave velocity is _____________ the velocity of longitudinal waves.
Approximately 1/2
The linearity of an ultrasonic testing system can be verified with ____________ amplitude blocks.
Area
Several sets of ASTM reference blocks provide a combination of __________ amplitude and ______________ amplitude blocks.
Area, Distance
When the shape of a test specimen makes comparison to a standard reference block impractical, _____________ may be added to a sample of or the test specimen itself as reference discontinuities.
Artificial Discontinuities
To evaluate the size of a discontinuity in a test part, the amplitude of the indication from the true discontinuity can be compared to the amplitude of the indication from an artificial discontinuity:
At the same sound-path distance.
The DAC (Distance Amplitude Correction) is used to compensate for the __________ of sound as it travels deeper into the specimen.
Attenuation
The gradual loss of energy as a beam travels through a material (medium) is known as:
Attenuation
The display which shows a cross-sectional view of the test specimen is known as the ______________ presentation.
B-Scan
Discontinuities may cause a reduction or complete loss of the _____________ indication, depending on the size of the discontinuity.
Back Surface
In contact testing, the initial pulse, main_____________, and front ____________ reflection are all represented by the same indication.
Bang, Surface
The intensity control of an ultrasonic test instrument regulates the brightness of the CRT:
Baseline
Collimators are added to transducers to reduce the effects of ______________ and improve the line of direction of the sound beam.
Beam Spread
__________ in long specimens may cause spurious indications through mode conversion.
Beam Spread
The contour or shape of a discontinuity from the examination (top) surface is shown in the ____________ presentation.
C-scan
More than one area of the sweep __________ be gated at the same time.
Can
When more than one area of the sweep is gated, the alarm sensitivity settings:
Can be different
Velocity of sound _______________ from one medium to another.
Changes
Transducer resolution is a measure of its ability to produce separate indications on the CRT for discontinuities.
Close together in sound path
Materials with ___________ grain structure are difficult to test.
Coarse
Increasing the range control setting ____________ the sweep.
Compresses
The velocity of ultrasound is dependent on the density and elastic properties of the medium. In addition, velocity varies from one medium (e.g water) to another (e.g steel) but is _________________ within a given medium.
Constant
In __________ testing, the transducer physically touches the test material.
Contact
The international Institute of Welding (11W) calibration block used in _____________ testing.
Contact
Cylindrically-focused lenses on transducers that cause the sound energy to strike curved test surfaces normal to the surface at all points are called ______________ lenses.
Contour-Correction
Devices (usually plexiglass) added to the front of contact transducers to match the curvature of a test part are called:
Contoured Wedges
Most couplants also have a _____________ added.
Corrosion inhibitor
A thin film of _____________ is used between the transducer and test specimen in contact testing.
Couplant
Since air is a poor conductor of ultrasonic energy a _______________ is used between the transducer and the test specimen to exclude air.
Couplant
The impedance ratio between mediums can be improved by using a(n):
Couplant
Water, glycerin, oil, and grease are the most common _____________. Gaseous mediums, for example air, makes __________ couplants.
Couplants, Poor.
Contoured wedges ensure good ______________ between the transducer and the test part.
Coupling
A vibration is the back-and-forth movement of something as shown above. The distance X is a displacement in one direction; the distance Y is a displacement in the opposite direction. One complete movement, first in one direction and then in the opposite direction is called a:
Cycle
Frequency is often abbreviated as Hz. This means:
Cycles Per Second
Digital thickness gauges utilize the _____________ circuit to present the first indication of interest on a _____________ display.
DAC, digital
The area beneath the front surface of a specimen from which no reflection can be observed is called the:
Dead Zone
The lower the frequency of a transducer, the less the sound energy attenuated and the deeper the sound energy will penetrate the part. At the same time, the sensitivity will ____________ and the beam spread will ______________.
Decrease, Increase
To increase the depth of penetration of the sound beam in the test material, the frequency should be:
Decreased
Beam intensity _____________ as the distance from the center of the beam increases.
Decreases
In immersion testing, the ____________ control is used to move the initial pulse off the CRT screen.
Delay
Distance amplitude blocks provide discontinuity ______________ reference.
Depth (or sound path)
Standard reference blocks are made from carefully selected, ultrasonically tested stock that is ____________ free.
Discontinuity
The distance between the front surface indication and a discontinuity indication represents the distance between the test surface and the:
Discontinuity
Fine porosity appears on a CRT as many ____________ indications of varying______________.
Discontinuity, Amplitude
If a surface is depressed and held, the distance the surface moved is called a:
Displacement
The baseline represents time, but in ultrasonic testing it also represents:
Distance
The tendency for a beam of sound to spread is known as:
Divergence or beam spread
Two single transducers, one a transmitter and the other a receiver, mounted in a common case (housing) but separated by a sound barrier are called ______________ transducers.
Dual-Element
Particle motion in surface waves follow an ____________ orbit.
Elliptical
Lamb wave particle motion in plate is in the form of complex ____________ orbits, the motion being either ___________ or _____________.
Elliptical, symmetrical, asymmetrical
The gate width control is used to position the __________ of the gate.
End
Since a vibration is moving particles within a test specimen, a vibration is really a back-and-forth movement of:
Energy
Total Reflection means no incident beam __________ is/are being transmitted through an interface.
Energy
A transducer capable of detecting a 3/64 inch (1.2mm) flat-bottomed hole 1/16 inch (1.6mm) below the surface of a test part has ____________ resolving power.
Excellent
The range control is used to __________ or _________ the display on the CRT screen.
Expand, Compress
Irregularly-shaped specimens may create ___________ discontinuity indications.
False
The angle of incidence which causes 90 degrees refraction of the longitudinal wave is called the _________ angle.
First Critical
Artificially discontinuities are added to the reference blocks in the form of precisely drilled _____________ holes.
Flat-bottomed
Time is required for a vibration to move through one complete cycle. Of course, most vibrations pass through several cycles. The number of cycles in one second is called the:
Frequency
Plate wave velocity depends on wave __________, _________ angle, the type of material, and the ___________ of the material.
Frequency, Incident, Thickness
The delay permits ultrasonic viewing of segments of a specimen beyond the _____________ surface.
Front
The front and back surface signals from the test specimens can be eliminated from C-scan records by __________ circuits.
Gating
The higher the frequency of a transducer, the ______________ the sensitivity and resolution.
Greater
The amplitude of an indication from a smooth surface discontinuity is ______________ one form a rough surface.
Greater Than
Ultrasonic systems make __________ automatic scanning possible.
High-Speed
____________ are used to show units of time or distance.
Horizontal screen divisions
The transducer does not physically touch the test material (specimen) in:
Immersion Testing
Impedance mismatch between mediums is known as the:
Impedance Ratio
The acoustic ______________ of a couplant should lie between the acoustic ________________ of the transducer and that of the test specimen.
Impedance, Impedance
Mode conversion is the transformation of a(n) ________________ beam into other modes of vibration.
Incident
Ultrasonic waves approaching an interface are called the ____________ waves.
Incident
In order to penetrate coarse-grained materials or thick specimens, the pulse length must be:
Increased
Increasing the sensitivity control ________ the amplitude (height) of the indications on the CRT screen.
Increases
Increasing the sound beam frequency ______________ attenuation.
Increases
Reflections from the dead zone are obscured by the:
Initial Pulse
The indication that appears on the left side of the screen is the:
Initial Pulse
In an A-scan presentation, the first indication is the __________, while a discontinuity indication will be displayed anywhere between the first signal and the signal representing the back____________.
Initial Pulse, Surface Reflection
The height of an A-scan signal indicates wave ____________ and the space between the indications represents _________ or ___________.
Intensity, Time, Distance
The surface between two media is called the:
Interface
Coarse grain structure causes multiple ___________ to appear between the front and back surface indications on a CRT which tend to obscure discontinuity indications.
Irregular Indications
When the amplitudes of the indications from a true discontinuity and an artificial discontinuity are the same, and both are the same sound-path distance, the true discontinuity will be _______________ the artificial discontinuity.
Larger Than
The expansion or compression of the sweep with the range control is toward or away from the ____________ side of the CRT screen.
Left
The A-scan presentation is read:
Left to Right
The baseline of the CRT represents time progressing from:
Left to Right
The pulse ____________ control is used to regulate the length of the pulse.
Length
B-Scan presentation pictorially shows the _____________ of a discontinuity and its _________ below the examination surface.
Length, Depth (distance)
Because of the secondary or side lobe effect at the face of a transducer, the useful width of the transducer is _______________ than the transducer's physical width.
Less
Decreasing the range causes __________ of the test specimen to be displayed on the CRT screen.
Less
Nonmetallic inclusions produce reflections having ________________ amplitude than similar size cracks or voids.
Less
Immersion testing is where both the transducer and the test specimen (usually) are placed in (an):
Liquid Couplant
In contact angle beam testing, the beam exit point and the exact angle of refraction of the transducer must be known to accurately determine the _______________ of a discontinuity in the test specimen.
Location
____________ waves will propagate through solids, liquids, and gasses.
Longitudinal
Waves in which particle vibration is in the direction of propagation are called _____________ or ____________ waves.
Longitudinal, Compression
In contact angle beam testing, some sound is _____________ in the wedge.
Lost (attenuated)
Large single-element (crystal) transducers are generally limited to __________ frequency testing.
Low
When comparing two transducers of the same size, the _____________ frequency transducer has a spreading or divergent beam.
Lower
The testing system must be recalibrated whenever a different kind of __________ is to be tested and whenever any ________ of the test system is replaced.
Material, Component
An ultrasonic beam is a small, narrow beam of:
Mechanical Energy
When a sound beam strikes an interface between two different media at an angle, _____________ occurs.
Mode Conversion Beam Refraction Beam Reflection
The size of a transducer and the amount of sound energy it transmits are also related. The larger the transducer, the ___________ sound energy it transmits into the test part.
More
When comparing two transducers with the same frequency, the smaller diameter transducer has _____________ beam divergence than the larger diameter transducer.
More
The beam spread of transducers of the same material and frequency is related to their size. The larger the transducer, the _____________ the beam spread.
Narrower
The ____________ zone is the zone of irregular intensities.
Near
Dual-element pule-echo testing has better ____________ resolution because the ______________ zone is less of a factor.
Near surface, Dead
The _____________ zone is that part of a sound beam closest to the transducer with the ______________ zone beyond.
Near, Far
A straight beam transducer is one that transmits the sound energy into the test part ______________ to the surface of the test part.
Normal
The detection of a discontinuity sometimes depends on its surface:
Orientation
Long, narrow transducers made up of a mosaic pattern of small crystals carefully matched to produce a sound beam of uniform intensity are called _____________ transducers.
Paint Brush
The flat bottom of the artificial discontinuity hole must be ________________ to the test surface of the block.
Parallel
The ideal specimen shape or geometry is one where the front and back surfaces are:
Parallel
A relationship exists between the frequency and the time required to complete one cycle. If the frequency is known, we can divide the frequency into one (1/f) and get the time required for one complete cycle. The time required for one complete cycle is called the:
Period
Ultrasonic systems also provide a _________ of the ultrasonic test.
Permanent Record
Normal incidence occurs when the incident beam is ___________ to the interface.
Perpendicular
The angle of refraction is the angle formed between a refracted wave as it passes through an interface and a line drawn ______________ to the interface.
Perpendicular
The purpose of angle beam transducers is to locate and evaluate discontinuities that lie ________________ to the surface of the test part.
Perpendicular
A ___________ transducer (crystal) can convert electrical energy to mechanical energy; or mechanical energy to electrical energy.
Piezoelectric
A C-scan recording displays a ____________ view of the discontinuities in the test specimen.
Plan
The C-scan presentation is a ___________ presentation.
Plan View
Waves which propagate only through thin sheets, plate, or thin-walled tubing are called ________ or ___________ waves.
Plate, Lamb
Rough surfaces may block sound _________ or cause spurious _____________ indications on the cathode-ray tube (CRT).
Propagation, Non relevant
The pulse repetition rate control is used to regulate the ____________ rate.
Pulse
The system which uses reflected energy to find discontinuities is called the __________ system.
Pulse Echo
The wheel-type transducer is equally adaptable to _____________ and ____________ testing.
Pulse-echo, Through-transmission
The pulse echo system uses only _____________ wave trains, while the through-transmission system can use _____________ wave trains.
Pulsed, either continuous or pulsed
The vertical positioning control of an ultrasonic instrument is used to __________ and __________ the baseline on the CRT screen.
Raise, Lower
In conjunction with the ____________ control, the delay makes it possible to view just a small segment of the test specimen in the entire width of the CRT screen.
Range
A piezoelectric crystal can both send and _________ energy.
Receive
The sensitivity, or gain control, adjusts the gain of the:
Receiver Amplifier
The initial pulse width, also called the test system ___________ time, determines the dead zone.
Recovery
The ideal way to evaluate UT discontinuity indications would be to compare them to a _______________ that contains real flaws.
Reference Specimen
The flat-bottomed hole parallel to the surface of the reference block is an ideal _____________ for the sound beam.
Reflecting Surface
An incident beam's angle of ___________ at an interface is equal to its angle of _____________.
Reflection, Incidence
Contact angle beam transducers are generally identified by the _____________ angle of the _____________ wave generated.
Refracted, Shear
The bending of an incident beam as it passes through an interface is called:
Refraction
Discontinuity indications appearing to the _____________ of the first back surface reflection are spurious or false indications and can be ignored.
Right
The reflection from a _____________ surfaced discontinuity scatters the sound beams.
Rough
The brightness of the CRT scale is controlled by the ____________ illumination control.
Scale
Adding acoustical lenses to transducers increases the ______________ and _______________ but shortens the depth _______________ of the transducer.
Sensitivity, Resolution, Range
In through-transmission testing, ____________ are used to transmit and receive energy.
Separate Transducers
The focus control and the astigmatism controls are used to adjust the ___________ of the baseline.
Sharpness
Angle beam transducers are also used to generate _______________ waves by mode conversion.
Shear, Longitudinal, Surface
Surface waves have a velocity slightly less than ___________ waves and travel only on the surface of ______________.
Shear, Solids
Waves in which particle vibration is perpendicular to the direction of propagation are called ___________ or ___________ waves.
Shear, Transverse
A ________________ focal-length transducer has the best near surface resolution.
Short
The best resolution is obtained with the __________ usable pulse length.
Shortest
The 11W calibration block and the test specimen must be made of ________________ material.
Similar
When comparing ultrasonic indications from a test specimen to the responses from a standard reference block, both reference block and test specimen must be of ______________ material.
Similar
Area amplitude blocks provide discontinuity ________________ references.
Size
The amplitude (height) of a indication on the CRT screen indicates the relative ____________ of the discontinuity.
Size
A large, high-frequency transducer has a ____________ beam spread.
Small
Spherically-focused lenses make the greatest improvement in sensitivity and resolution, but the area covered by the concentrated beam is very:
Small
The capability of a transducer is described by its sensitivity and resolution. Transducer sensitivity is its ability to detect:
Small discontinuities at given distances
The frequency of a transducer is a determining factor of its capability. The higher the frequency of a transducer, the ______________ beam spread.
Smaller
Refracted and reflected angles can be calculated using:
Snell's Law
Shear waves propagate only through:
Solids
Increasing the pulse length increases the amount of _____________ applied to the test specimen.
Sound Energy
Transducer sensitivity is rated by its ability to detect a certain size flat-bottomed hole at a specific _______________ in a standard reference block
Sound Path
The amplitude for a given size discontinuity will vary with increasing:
Sound Path Distance
The distance between the flat-bottomed hole (artificial discontinuity) and test surface is known as the ____________ distance.
Sound-path
In a set of distance amplitude blocks, the variable is the:
Sound-path distance
The confusing indications from a rough surface or metal noise can frequently be reduced by the use of a ______________ focuses lens.
Spherically
Calibrating a pulse-echo ultrasonic system means noting its response to known:
Standards
In the flaw-alarm/gating circuits, the gate delay control is used to position the ___________ of the gate.
Start
The delay control changes the __________ point of the baseline.
Starting
The horizontal positioning control is used to adjust the ___________ point of the baseline on the CRT.
Starting
The initial pulse represents the point in time where the ultrasonic test:
Starts
The drive motors used in scanners for many system applications are called ____________ motors.
Stepper
When the angle of incidence is such that the shear wave mode is refracted to 90 degrees (second critical angle) _______________ waves may be developed.
Surface
An important factor in coupling the transducer to the specimen in the specimen's:
Surface Condition
An angle beam transducer that generates a shear wave with a refracted angle of 90 degrees is also called a ____________ wave transducer.
Surface.
Vertical deflections of the baseline (indications) represent ____________ that reflect sound.
Surfaces
Soon after the pulse-echo instrument power switch is turned on, a line of light appears across the CRT screen. This line is called the:
Sweep Line
The choice of couplant is largely dependent upon the condition of the:
Test Surface
In immersion testing, the couplant is:
The liquid (water) bath.
With the DAC control properly set, the indication amplitude from a 3/64 inch (1.2mm) flat-bottomed hole 2 inches (50.8mm) below the surface will be ________________ a 3/64 inch (1.2mm) flat-bottomed hole 1 inch (25.4mm) below the surface.
The same size as
Since the ultrasonic energy from one pulse must have time to return to the transducer before the next pulse starts, the ______________ of the test specimen is a governing factor.
Thickness
To ensure good sound transfer, the couplant must be used as________________ as possible, yet viscous enough to stay on the surface.
Thin
Contact testing is generally limited to low frequencies because crystals cut for use above 10 Mhz are _____________ and _______________ for practical contact testing.
Thin, Fragile
Transducer frequency and crystal thickness are also related. The higher the frequency, the _____________ the crystal.
Thinner
The test system which uses variations in received energy amplitude to indicate discontinuities is called:
Through-Transmission
When the angle of incidence exceeds the second critical angle (for shear waves), _____________ occurs.
Total Reflection
A device which converts energy from one form to another is known as a:
Transducer
In immersion testing, we tilt the ___________ to find or evaluate discontinuities orientated other than parallel to the specimen's surface.
Transducer
In ultrasonic testing, the ultrasound injected into the material can be pulsed or continuous. The device used to inject the vibrations into the material is called a(n):
Transducer
Couplants ensure maximum energy __________ between mediums.
Transfer or transmission
In the pulse echo system, a single transducer is used (usually) as both the _________ and the ________.
Transmitter, Receiver
Single-element (crystal) transducers may be _____________ only, ________________ only, or both.
Transmitter, Receiver
A B-scan or a C-scan can provide information about the through-wall extent of a discontinuity.
True
A C-scan recording displays depth information about a discontinuity.
True
A sonic vibration is back-and-forth movement of energy passing through a material as a series of small particle displacements. The frequency of vibration used in ultrasonic testing is normally above the range of human hearing. When the frequency is within the range of human hearing, the vibration is called sound:
True
The miniature angle beam block (rompas block) is a limited version of the 11W block intended for use in the field.
True
Transducer resolution is rated by the transducer's ability to discriminate between two closely-spaced reflectors.
True
Vibrations above 20,000 Hz are called __________ vibrations.
Ultrasonic
The thickness of the couplant must also be kept ____________ to prevent altering the direction of the sound beam.
Uniform
Ultrasound moves as a series of small particle displacements and is energy in motion. The speed of movement through the material is called the:
Velocity
Various wave modes are used in ultrasonic testing; for example, longitudinal, shear, surface, etc. The speed at which a wave mode propagates through a medium depends on the characteristic ultrasonic _____________ for the medium.
Velocity
Ultrasonic testing is concerned with the back-and-forth movement of small particles of material within a test specimen. This back-and-forth movement is called a:
Vibration
The technique of immersion testing that employs a flowing stream of water between the transducer and the best part, but does not require that the test part be immersed, is called the _______________ technique.
Water Column (bubbler or squirter)
An ultrasonic sound beam propagates through a medium as ___________ of ______________.
Waves, Particle Vibrations
Contact Angle Beam transducers transmit the sound energy into the test part at angles other than normal by the use of a:
Wedge
To exclude air from between the transducer and the test surface, the couplant must ________________ the surface.
Wet
To improve the wetting ability of the couplant and help it stay on the surface, a ______________ is added.
Wetting Agent
Paint Brush transducers are used for scanning _________ areas.
Wide
Three axes of scanner movement are possible with ultrasonic immersion systems. They are the:
X, Y, and Z axes.
Ultrasonic vibrations (sound energy) travel _______________ through air.
poorly
In ultrasonic testing, the term "vibration" is used interchangeably with the term:
ultrasound
