ASNT NDT Handbook Volume 7 ultrasonic Testing

A different version of an ultrasonic Practice of Wheel Ultrasonic
scanning system is used for the inspection Testing
of hollow axles found in urban transit
systems. In this case, transverse rather Most commonly, ultrasonic wheel
than longitudinal transducers (about inspection is performed using surface
3 MHz frequency) are hosted in a piglike waves on the wheel tread and flange
probe inserted into the hollow of the axle. (Fig. 12).51 For complete coverage,
Angle beam testing, typically at 0.79 rad scanning can be done in both the axial
(45 deg) and 1.13 rad (65 deg), is used to direction (across the rim section) and the
detect the cracks. Three-dimensional radial direction (from the tread surface).52
coverage is provided by rotating the pig Both reflection and transmission
and then translating it to a new axial measurements can be used for detecting
position. discontinuities. Phased arrays can also be
used to relax the requirements for
One challenge associated with any scanning. Both stationary and in-motion
ultrasonic technique of axle inspection is tests are possible. In-motion tests use
that results vary because of inconsistent either dry coupling, water immersion or
coupling between the ultrasonic probes noncontact electromagnetic acoustic
and the axle surface. This problem is transducers. Full inspection is
particularly critical in automated scanning accomplished by a single 6.3 rad (360 deg)
systems where data are acquired in real rotation of the wheel.
time while the axle rotates.
Ultrasonic Measurement of
Ultrasonic Testing of Residual Stress in Wheels
Wheels
Circumferential tensile stresses can build
Motivation up in wheels because of heat input from
braking. As for rail tracks, residual stresses
Failure of the wheels is another problem in wheels can be measured with
of railroad systems, flanges being the top acoustoelastic ultrasonic tests.53
wheel problem. For example, anomalous
flanges caused about 360 of the total
680 derailments attributed to wheel
failures from 1992 to 2002 in the United
States, corresponding to about
30 000 000 dollars in reportable damage.

Wheel Discontinuities

Discontinuities found in train wheels
include broken and worn flanges, broken
rims and thermal cracks formed by heat
generated friction and quenching.

FIGURE 12. Transducer arrangements for wheel tests.

Flange Surface wave
Tread transducers

Rim

540 Ultrasonic Testing

PART 3. Ultrasonic Testing in Marine Industry54

Ultrasonic testing is an important tool in Tests of Pipe
the marine industry, in new construction
and in ship repairs. Its primary purpose is The extrusion and drawing processes used
to ensure that materials and components to manufacture pipe tend to elongate
in a ship’s construction or repair meet discontinuities in a direction parallel to
prescribed quality levels such that the the pipe axis. The most common pipe
vessel meets its performance requirements discontinuities are laps, seams and cracks.
as designed. Ultrasonic testing is used in These are easily detected using transverse
naval and commercial shipbuilding. wave ultrasonic tests around the
Although governed by different circumference of the pipe.
specifications and codes, the ultrasonic
tests are very similar. Such techniques involve 100 percent
scanning and may be in only one or in
Applications of ultrasonic testing in the two opposite circumferential directions,
marine industry vary widely depending some specifications also requiring an axial
on the type of vessel, its operating scan. Calibration is based on inside and
environment and its use. The materials outside diameter notches, with depths
and components to be tested, the extent typically equal to 3 or 5 percent of the
of the testing and the criteria used for the wall thickness. Acceptance is based on
tests are specified by the vessel’s designer amplitude comparison.
or owner. In general, there are three major
testing categories: (1) material testing, Tests of Bar Stock
(2) fabrication testing and (3) inservice
testing. Some common techniques are The rolling or forging processes used to
briefly described below. manufacture bar stock also tend to
elongate discontinuities in an axial
Ultrasonic Material Tests direction. The discontinuities are usually
toward the center of the bar and are best
Tests of Plate detected by compression wave testing
transverse to the axis.
During the plate rolling process,
impurities or voids present in the ingot The test typically involves scanning at
become compressed into laminar least half the circumference of round
discontinuities in the finished plate. A stock and one of each pair of parallel sides
compressional wave test from one major for multisided bar. Calibration is based on
surface is used to detect and evaluate this drilled flat bottomed holes. Bars may also
condition. Calibration may be based on be tested in the axial direction by
the response from flat bottomed holes inducing sound through one end and
drilled to mid thickness but is most often monitoring the back reflection.
based on the back surface reflection
height. Tests of Forgings

Such tests may involve 100 percent Forging discontinuities are usually
scanning of one major surface, scanning oriented in the direction of the forging
along grid lines or static tests at criticality flow lines. However, in complex shapes,
of a grid, depending on the effect of discontinuities may lie in more than one
laminations on the intended use of the direction and are often difficult to predict.
plate. Consequently, a combination of
transverse and compression waves is often
Small laminar discontinuities are used to ensure adequate coverage of the
usually not considered critical to a plate’s forging in two or three directions.
serviceability: they are judged by size and
proximity to each other. However, plates The number and type of scans depend
in applications where stress loads are on the type of forging (hollow,
perpendicular to their planar surfaces may rectangular, round, multisided or disk).
be required to be free of laminar Calibration is based on flat bottomed
discontinuities. holes for compression wave testing and
3 or 5 percent notches for transverse wave
tests. Size and amplitude are the deciding
factors.

Special Applications of Ultrasonic Testing 541

Tests of Castings perpendicular to the weld in opposite
directions and also parallel to the weld.
The most common discontinuities found The refracted angle of 0.8, 1.0 or 1.2 rad
in castings are porosity, slag inclusions, (45, 60 or 70 deg) depends on the
shrinkage, cold shuts, hot tears and thickness of the weld being tested. Welds
cracks. Most of these discontinuities are may be scanned in the as welded
oriented completely at random. condition or in the flush (ground)
Consequently, compression wave condition for butt and corner welds.
ultrasonic tests in three directions 1.5 rad
(90 deg) to each other are recommended Calibration is based on the reflections
when possible. from side drilled holes in a reference
standard. Acceptance criteria are usually
Calibration is usually based on the based on length of discontinuity and
response from drilled flat bottomed holes height of reflected signal.
of varying depths but also may be based
on the back reflection height. Amplitude Discontinuities in T Welds
and size are used to determine
acceptability. If a T weld requires 100 percent joint
efficiency, it may be ultrasonically tested
Thickness Tests to ensure second side welding. The test is
performed using a compressional wave
With the exception of some cast technique from the through-member side.
materials, ultrasonic testing often can be The calibration standard may be a
used to measure material thicknesses. through member (back reflection
Accurate ultrasonic thickness technique) adjacent to the weld area, or a
measurement is not possible for stainless manufactured piece of similar material
steel castings and some nonferrous and thickness with a specific size
castings because of variations in sound machined square notch. Acceptance is
wave velocity through the cast structure. usually based on length and height of the
reflected signal.
Thickness testing involves a basic
compression wave test from one surface. Full and partial penetration T welds are
Calibration is based on known thicknesses tested for underbead discontinuities that
of acoustically similar materials. In extend into the through-member
addition to a single thickness at a given attachment. A transverse wave technique
point, scans may be performed over large is used, with the beam directed beneath
areas so that minimum or maximum the weld. The refracted angle, 0.8 or 1 rad
thicknesses are obtained. Static readings (45 or 60 deg), depends on the
on a grid pattern can also be taken for through-member thickness. Calibration is
specific thickness plots. based on side drilled holes. Acceptance is
usually judged on length, height of signal
Fabrication Tests and vertical height (distance of
propagation into the through member)
In the shipbuilding industry, most for all recordable discontinuities detected
ultrasonic tests are made on welds. in the area of interest.
Welding is the primary joining process for
marine vessels and the most common Bonding Tests
discontinuities found in welds are cracks,
incomplete fusion, incomplete Ultrasonic techniques are used to
penetration, slag and porosity. determine the degree of bonding in such
items as silver brazed pipe fittings, lead or
The extent of testing is governed by babbitt bearings and overlay cladding.
the design of the structure and the Bonding is determined by comparing the
materials used in construction. Depending ultrasonic test response to the signal
on the intended service and requirements patterns obtained from areas of bond and
of the designers, testing may cover a small unbond in a reference standard. Areas of
sampled area or a percentage, up to unbond produce reflections from the
100 percent coverage. Ultrasonics may be interface. Bonded areas permit ultrasound
used with radiography for greater to pass through the interface and produce
assurance. Ultrasonics is used to identify reflections from the composite thickness.
the planar discontinuities (such as lack of
fusion and cracking) and radiography is Inservice Tests
used to identify nonplanar discontinuities
(such as slag and porosity). Weld Tests

Volumetric Tests of Butt and Throughout the life of a pressure vessel,
Corner Welds surveillance testing is performed at
specific intervals to monitor known
Contact transverse wave techniques are
primarily used with beam directions

542 Ultrasonic Testing

discontinuities for changes and to detect
service induced cracks. The technique is
similar to the technique used for the
original weld testing.

Thickness Measurement

Ultrasonic thickness measurement is used
extensively in the marine industry to
monitor changes in thickness caused by
corrosion and steam or water erosion or
for any reason that thickness monitoring
becomes necessary.

The most common uses for thickness
surveillance are (1) to monitor the hull
thickness for corrosion caused by
exposure to sea water and (2) to monitor
piping systems for both corrosion and
erosion.

Water Level Determination

The level of water in a tank or piping
system can often be determined with
ultrasonic techniques. If the tank or pipe
is vertical, the presence of water is
indicated by the ability to transmit sound
through the diameter and obtain
reflections from the opposite wall. If a
tank is lying horizontally, the sound can
be transmitted from places on the bottom
of the tank and reflected off the surface of
the water, so the actual height of the
water can be measured.

Special Applications of Ultrasonic Testing 543

PART 4. Acoustic Microscopy55

Acoustic microscopy is a general term is suited to a particular application.
applied to high resolution, high frequency Acoustic microscopes have been especially
ultrasonic test techniques that produce useful in solving problems with new
images of features beneath the surface of a materials and components not previously
test object. Because ultrasonic energy available. The three types of acoustic
requires continuity to propagate, microscopes are very different from each
discontinuities such as voids, inclusions, other and this discussion should provide
delaminations and cracks can interfere the potential user with an awareness of
with the transmission or reflection of their distinctions to maximize
ultrasonic signals. opportunities for successful acoustic
microscopy.
Conventional ultrasound techniques
operate between 1 and 10 MHz. Acoustic Fundamentals of Acoustic
microscopes operate up to and beyond Microscopy Techniques
1 GHz, where the wavelength is very short
and the resolution correspondingly high. For the purposes of comparison, the
In the early years of acoustic microscopy, scanning laser acoustic microscope is
it was thought that the highest primarily considered a transmission mode
frequencies would dominate applications. instrument that creates true real time
However, because of high attenuation, the images of a test object throughout its
frequency range from 10 to 100 MHz is entire thickness. (The reflection mode is
used most extensively. sometimes used.) In operation, ultrasound
is introduced to the bottom surface of the
Acoustic microscopy comprises three test object by a piezoelectric transducer
distinct techniques: (1) scanning laser and the transmitted wave is detected on
acoustic microscopy (SLAM), introduced the top by a rapidly scanning laser beam.
in the literature in 1970 (Fig. 13),56,57
(2) C-mode scanning acoustic microscopy, The other two systems are primarily
a variation of familiar C-scan reflection mode instruments that use
instrumentation and (3) scanning acoustic transducers with an acoustic lens to focus
microscopy (SAM).57,58 the wave at or below the test object

These techniques are complementary
to each other. Often, only one technique

FIGURE 13. Principle components of scanning laser acoustic microscope.

Beam scanners Knife edge and
photodetector
Laser

Angular modulation of Optical signal Acoustic signal
laser beam as it reflects
Imaging optics from wrinkle on coverslip processor processor
Plastic mirror
Laser raster Optical Acoustic
Fluid couplant signal signal
display display

Acoustic frequency Continuous Reflective surface
generator plane wave of mirror
insonification Test object
Ultrasonic
transducer Ultrasound passes through test object
and wrinkles mirrored surface

544 Ultrasonic Testing

surface. The transducer is mechanically images are produced in real time
translated (scanned) across the test object (30 images per second) and are displayed
in a raster fashion to create the image. on a high resolution monitor. In contrast
The C-scan acoustic microscope system to less accurate uses of the term real time,
can image several millimeters or more the scanning laser acoustic microscope
into most test objects and is ideal for can be used to observe events as they
analyzing at a specific depth. Because of a occur — for example, a crack propagating
very large top surface reflection from the under an applied load.
test object, this type of microscope is not
effective in the zone immediately below The images produced by scanning laser
the surface unless rayleigh waves are used acoustic microscopy are shadowgraphs of
with wide aperture transducers. structure throughout the thickness of the
test object. This provides the distinct
The scanning acoustic microscope uses advantage of simultaneous viewing of the
rayleigh waves for very high resolution entire test object thickness, as occurs in
images of the surface and near surface of a X-radiography. In situations where it is
test object. Penetration depth is limited to necessary to focus on one specific plane,
one wavelength of sound because of the holographic reconstruction of the
geometry of the lens. For example, at scanning laser acoustic microscopic data
1 GHz, the penetration limit is about 1 µm can be used.60,61
(4 × 10–5 in.). The C-scan acoustic
microscope is designed for moderate In a scanning laser acoustic
penetration into a test object, and microscope, in addition to an acoustic
transmission mode imaging is sometimes image on the display, an optical image is
used. This instrument uses a pulse echo produced by means of the direct scanned
transducer, and the specific depth of view laser illumination of the test object
can be electronically gated. surface. For this mode, the reflective
coating on the cover slip is made
Scanning Laser Acoustic semitransparent. The optical image serves
Microscopy Operating Principles as a reference view of the test object that
the operator consults for landmark
A collimated plane wave of continuous information, artifacts and positioning of
wave ultrasound at frequencies up to the test object to known areas.
several hundred megahertz is produced by
a piezoelectric transducer beneath the test These acoustic images also provide
object (Fig. 13). Because this ultrasound useful and easily interpreted quantitative
cannot travel through air (making it an data about the test object.62 For example,
excellent tool for crack, void and disbond the brightness of the image corresponds
detection), a fluid couplant is used to to the acoustic transmission level. Precise
bring the ultrasound to the test object. insertion loss data can be obtained by
Distilled water, spectrophotometric grade removing the test object and restoring the
alcohol or other more inert fluids can be image brightness level with a calibrated
used, depending on user concerns for test electrical attenuator placed between the
object contamination. transducer and its electrical driver. With
the acoustic interference mode, the
When the ultrasound travels through velocity of sound can be measured in each
the test object, the wave is affected by the area of the test object.63 When these data
homogeneity of the material. Wherever are used to determine regionally localized
there are anomalies, the ultrasound is acoustic attenuation loss, modulus of
differentially attenuated and the resulting elasticity and so on, the elastic
image reveals characteristic light and dark microstructure can be well characterized.
features, corresponding to the localized
acoustic properties of the test object. The simplest geometries for scanning
Multiple views can be made to determine laser acoustic microscopic imaging are flat
the specific depth of a discontinuity — plates or disks. However, with proper
such viewing is performed by fixturing, complex shapes and large test
stereoscopy.59 objects can also be accommodated. For
example, tiny hybrid electronic
A laser beam is used as an ultrasound components, large metal plates
detector by sensing the infinitesimal (250 × 250 mm or 10 × 10 in.), aircraft
displacements at the surface of the test turbine blades and ceramic engine
object — that is, the rippling from the cylinder liner tubes have been tested with
ultrasound. In typical test objects that do scanning laser acoustic microscopy.
not have polished, optically reflective
surfaces, a mirrored plastic block, or cover C-Scanning Acoustic Microscopy
slip, is placed close to the surface and is Operating Principles
acoustically coupled with fluid. The laser
is focused onto the bottom surface of the The C-scanning acoustic microscope is
cover slip, which has an acoustic pattern primarily a pulse echo (reflection)
that corresponds to the test object surface. microscope that generates images by
By rapid sweeping of the laser beam, mechanically scanning a transducer in a
raster pattern over the test object. A

Special Applications of Ultrasonic Testing 545

focused spot of ultrasound is generated by typical scan areas the size of an integrated
an acoustic lens assembly at frequencies circuit.
from 10 to 100 MHz.
It is well known that the large echo
The ultrasound is brought to the test from a liquid-to-solid interface (the top
object by a coupling medium, usually surface of the test object) masks the small
water or an inert fluid. The angle of the echoes that may occur near the surface
rays from the lens is generally kept small within the solid. This characteristic is
so that the incident ultrasound does not known as the dead zone and its size is
exceed the critical angle of reflection usually on the order of a few wavelengths
between the fluid coupling and the solid of sound. Below the surface, the
test object. The focal distance into the test maximum depth of penetration is
object is shortened considerably by the determined by the attenuation losses in
liquid-to-solid refraction. The transducer the test object and by the geometric
alternately acts as sender and receiver, refraction of the acoustic rays, which
being electronically switched between the shorten the lens focus by the solid
transmit and receive modes. A very short material. Appropriate transducers and
acoustic pulse enters the test object and lenses must be used for optimum test
return echoes are produced at the object results, depending on the depth of
surface and at specific interfaces within interest.
the test material.
Scanning Acoustic Microscopy
Pulse return times are a function of the Operating Principles
distance from the interface to the
transducer. An oscilloscope display of the The scanning acoustic microscope is
echo pattern (an A-scan) clearly shows primarily a reflection microscope that
these levels and their time-versus-distance generates very high resolution images of
relationships from the test object surface. surface and near surface features by
This response provides a basis for mechanically scanning a transducer in a
investigating anomalies at specific levels raster pattern over the test surface. In the
within a test object. An electronic gate normal mode, an image is generated from
selects information from a specified level echo amplitude data over an X,Y scanned
while it excludes all other echoes. The field of view. As with scanning laser
gated echo brightens a spot on a display acoustic microscopy, a transmission
showing the C-scan. The image follows interference mode can be configured for
the transducer position and is brightened velocity of sound measurements. In
by signals in the gate. contrast to C-scan acoustic microscopy, a
more highly focused spot of ultrasound is
Older, conventional C-scan generated by a very wide angle acoustic
instruments produce monoamplitude lens assembly at frequencies typically
output on thermal paper when a signal ranging from 100 to 2000 MHz. The angle
exceeds an operator selected threshold. By of the sound rays is well beyond the
comparison, the output of the C-scanning critical cutoff angle, so that there is
acoustic microscope is displayed in full essentially no wave propagation into the
gray scale, the gray level being material.
proportional to the amplitude of the
interface signal. The gray scale can be There is a rayleigh (surface) wave at the
converted into false color and the images interface and an evanescent wave reaches
can be color coded with echo polarity to about one wavelength below the
information.64 surface. As in the other techniques, the
ultrasound is brought to the test object by
In such displays, positive echoes arise a coupling medium, usually water or an
from reflections off lower impedance inert fluid. The transducer alternately acts
interfaces and are displayed in a different as sender and receiver, being
color. This allows quantitative electronically switched between the
determination of the nature of the transmit and receive modes. However,
interface within the test object. For instead of a short pulse of acoustic energy,
example, the echo amplitude from a a long pulse of gated radiofrequency
plastic ceramic boundary is very similar to energy is used. No range gating is
that from a plastic air gap boundary, possible, as in C-scan acoustic microscopy,
except that the echoes are 3.14 rad because of the design of the scanning
(180 deg) out of phase. To determine acoustic microscope. The returned
whether or not an epoxy is bonded to a acoustic signal level is determined by the
ceramic, echo amplitude analysis alone is elastic properties of the material at the
not sufficient. near surface zone. The returned signal
level modulates a cathode ray tube
The color coded enhanced microscope synchronized with the transducer
is further differentiated from conventional position. In this way, images are produced
C-scan equipment by the speed of the in a raster scan on the cathode ray tube.
scan. Here, the transducer is positioned by As with C-scan acoustic microscopy,
a very fast mechanical scanner that
produces images in tens of seconds for

546 Ultrasonic Testing

complete images are produced in about and scanning acoustic microscopy all
10 s. produce quantitative data in addition to
images.
With the scanning acoustic microscope
operating at very high frequencies, it is The most popular application of
possible to achieve resolution scanning laser acoustic microscopy and
approaching that of a conventional C-scanning acoustic microscopy is for
optical microscope. This technique is used nondestructive tests of bonding,
in much the same way as an optical delamination and cracks in materials.
microscope, with the important exception These instruments are often used for
that the information relates to the elastic process and quality control although a
properties of the material. Even higher significant percentage of the devices are
resolution than an optical microscope can placed in analytical and failure analysis
be obtained by lowering the temperature laboratories. The most popular application
of operation near absolute zero and using of scanning acoustic microscopy uses its
liquid helium as a coupling fluid. The very high magnification mode as a
wavelength in the liquid helium is very counterpart to conventional optical and
short compared to that of water, and electron microscopy, to see fine detail at
submicron resolution can be obtained.65 or near surfaces. The scanning acoustic
microscope, like the other acoustic
The scanning acoustic microscope has microscopy methods, produces image
been found useful for characterizing the contrast that is a function of the elastic
elastic properties of a test object over a properties of the test material
microscopic area determined by the (nonacoustic techniques may not).
transducer’s focal spot size. In this
technique, the reflected signal level is Acoustic Microscopy Tests of
plotted as a function of the distance Composite Materials
between the test object and the lens.
Leaky surface waves are generated by With a combination of materials having
mode conversion at the liquid-to-solid different properties and manufactured
interface as the test object is defocused anisotropy, acoustic microscopy can
toward the lens. For this reason, an clearly define the relevant property
interference signal is produced between distribution at the microscopic level. In
the mode converted waves and the direct general, composites contain interfaces
interface reflection. that cause scattering of ultrasound and
differential attenuation within the field of
The curve obtained is known as the view. This can be important in
V(z) curve. By analyzing its periodicity, the determining the population density shifts
surface wave velocity can be determined. of fibers within a test object.
Furthermore, defocusing the lens
enhances the contrast of surface features Acoustic microscopy can be used to
that do not otherwise appear in the differentiate fibers bonded to the matrix
acoustic image.66,67 In addition, by using a from fibers that are separated from the
cylindrical lens instead of a spherical lens, matrix. Excessive stress, for example,
the anisotropy of materials can be causes a separation. Scanning laser
uniquely characterized.68 acoustic microscopy can be used to image
complex shapes even though the
Acoustic Microscopy curvature may cause some restriction of
Applications the field of view because of critical angle
effects and lenslike actions by the test
Acoustic microscopy is compatible with object.
most metals, ceramics, glasses or polymers
and composites made from combinations In C-scan acoustic microscopy, the
of the above materials. The compatibility acoustic lens is focused within the
of a material is limited by ultrasound material near the top surface of the test
attenuation from scattering, absorption or object and the electronic gate is set to
internal reflection. receive the backscattered signal. Where
the test object is made with fibers
In metals, the grain structure causes distributed throughout its volume,
scattering losses. In ceramics, porosity acoustic energy is scattered from all
may cause losses. The magnitude of these depths, and distinct, time separated
effects generally increases with ultrasonic echoes are not generated. When the
frequency and the dependence is transducer is focused deep into the test
monotonic. The quantitative aspects of object, there is less definition of the fibers
this phenomenon have not yet found in the acoustic image, similar to that seen
widespread industrial acceptance although in the scanning laser acoustic microscope
they provide a basis for materials image.
characterization. The techniques of
scanning laser acoustic microscopy,
C-mode scanning acoustic microscopy

Special Applications of Ultrasonic Testing 547

Acoustic Microscopy Tests of
Ceramic Materials

Ceramic materials are used in many ways
and in many industries, including
electronics where they serve as substrates
for delicate hybrid circuits. In structural
applications, ceramics are used where
high temperature and light weight are
important. Silicon nitride, silicon carbide
and zirconia are being studied for
combustion engine applications.

Because of the inherent brittleness of
ceramic materials, small discontinuities
which may contribute to localized stress
concentrations are very critical to
structural integrity. The successful use of
these materials necessitates careful
nondestructive testing.

Attenuation changes in ceramics
correlate well with variations in
strength.69

Acoustic microscopy is a powerful tool
for nondestructively testing ceramic
materials and displaying internal
discontinuities and density gradients such
as porosity.

548 Ultrasonic Testing

References

1. Pettit, D.E. and D.W. Hoeppner. 9. Lewis, W.H., B.D. Dodd, W.H. Sproat
Contract Report NAS 9-11722 and J.M. Hamilton. USAF SA-ALC/MEE
LR 25387, Fatigue Flaw Growth and NDI 76-6-38-1, Reliability of Nondestructive
Evaluation for Preventing Through Cracks Inspections — Final Report (Have Cracks,
in Spacecraft Tankage Structures. Will Travel) (1978).
Washington, DC: National Aeronautics
and Space Administration 10. Rummel, W.D. “Recommended
(September 1972). Practice for a Demonstration of
Nondestructive Evaluation (NDE)
2. Rummel, W.D., P.H. Todd, Jr., Reliability on Aircraft Production
R.A. Rathke and W.L. Castner. Parts.” Materials Evaluation. Vol. 40,
“Detection of Fatigue Cracks by No. 9. Columbus, OH: American
Nondestructive Evaluation Methods.” Society for Nondestructive Testing
Materials Evaluation. Vol. 32, No. 10. (August 1982): p 922-932.
Columbus, OH: American Society for
Nondestructive Testing (October 1974): 11. Packman, P.F., S.J. Klima, R.L. Davies,
p 205-212. J. Malpani, J. Moyzis, W. Walker,
B.G.W. Yee and D.P. Johnson.
3. Haviland, G.P. and C. Tiffany. “Reliability of Flaw Detection by
AIAA Paper No. 73-18, “The USAF Nondestructive Inspection.” Metals
Aircraft Structural Integrity Program Handbook, Vol. 11: Nondestructive
(ASIP).” Proceedings of the American Inspection and Quality Control, eighth
Institute of Aeronautics and Astronautics edition. Materials Park, OH:
9th Annual Meeting and Technical ASM International (1976): p 414-419.
Display [Washington, DC,
January 1973]. Reston, VA: American 12. USAF MIL-HDBK-1823, Nondestructive
Institute of Aeronautics and Evaluation System, Reliability
Astronautics (1973). Assessment. Philadelphia, PA:
Document Automation and
4. MIL-A-83444, Airplane Damage Production Service, for the
Tolerance Requirements (for Future Aeronautical Systems Center of the
Procurements) [superseded by United States Air Force (1999).
MIL-A-87221]. Philadelphia, PA:
Document Automation and 13. Anderson, R.T., T.J. DeLacy and
Production Service, for the R.C. Stewart. NASA CR-128946,
Aeronautical Systems Center of the Detection of Fatigue Cracks by
United States Air Force (1987). Nondestructive Testing Methods.
Washington, DC: National Aeronautics
5. MIL-STD-1530, Aircraft Structural and Space Administration
Integrity Program (ASIP). Philadelphia, (March 1973).
PA: Document Automation and
Production Service, for the 14. Spencer, F.W., G. Borgonovi, D. Roach,
Aeronautical Systems Center of the D. Schurman and R. Smith.
United States Air Force (2005). DOT/FAA/CT-92/12, II, Reliability
Assessment at Airline Inspection
6. Rummel, W.D. and G.A. Matzkanin. Facilities: Vol. 2, Protocol for an Eddy
Nondestructive Evaluation (NDE) Current Inspection Reliability Experiment.
Capabilities Data Book, third edition. (1993).
Austin, TX: Nondestructive Testing
Information and Analysis Center 15. Berens, A.P. “NDE Reliability Data
(1997). Analysis.” Metals Handbook: Vol. 17,
Nondestructive Evaluation and Quality
7. USAF MIL-HDBK-5, Metallic Materials Control, ninth edition. Materials Park,
and Elements for Flight Vehicle Structure, OH: ASM International (1988):
Part B [superseded by Metallic Material p 659-701.
Properties Development and
Standardization (MMPDS)]. 16. Berens, A.P. and P.W. Hovey.
Washington, DC: United States “Statistical Methods for Estimating
Department of Defense. Crack Detection Probabilities.”
Probabilistic Fracture Mechanics and
8. DOT/FAA/AR-MMPDS, Metallic Fatigue Methods: Applications for
Material Properties Development and Structural Design and Maintenance.
Standardization. Washington, DC: Special Technical Publication 798.
United States Department of West Conshohocken, PA: ASTM
Transportation (2003). International (1983): p 79-94.

Special Applications of Ultrasonic Testing 549

17. NASA-STD-5009, Nondestructive 27. Smith, A. “Fatigue of Railway Axles:
Evaluation Requirements for Fracture A Classical Problem Revisited.”
Control Programs [draft]. Washington, Thirteenth European Conference on
DC: National Aeronautics and Space Fracture (ECF) [San Sebastian, Spain,
Administration (2005). October 2000]. Amsterdam,
Netherlands: Elsevier (2000):
18. NASA-STD-5013, Nondestructive p 173-181.
Evaluation Requirements for the
Durability and Damage Tolerance of 28. Zerbst, U., K. Mädler and H. Hintze.
Composites. Washington, DC: National “Fracture Mechanics in Railway
Aeronautics and Space Administration Applications — An Overview.”
(2000). Engineering Fracture Mechanics. Vol. 72,
No. 2. London, United Kingdom:
19. NASA-STD-5014, Nondestructive Elsevier (2005): p 163-194.
Evaluation (NDE) Implementation
Handbook for Fracture Control Programs 29. Bray, D.[E.] and G. Vezina. “Ultrasonic
[draft]. Washington, DC: National Applications in the Railroad Industry.”
Aeronautics and Space Administration Nondestructive Testing Handbook,
(2003). second edition: Vol. 7, Ultrasonic
Testing. Columbus, OH: American
20. Forsyth, D.S., A.P. Berens and Society for Nondestructive Testing
W.D. Rummel. “Nondestructive (1991): p 594-634.
Inspection Reliability and Risk in the
Field and Depot.” USAF Aircraft 30. Rail Defect Manual. Danbury,
Structural Integrity Program Connecticut: Sperry Rail Service
[San Antonio, TX, November 2006]. (1989).
Dayton, OH: Universal Technology
Corporation, for the United States Air 31. Report FRA/ORD-88-39. Washington,
Force Research Laboratory (2006). DC: Federal Railroad Administration
(1988).
21. Singh, R. Report Karta-3510-99-01
(AF Contract F41608-99-C-0404), Three 32. Anon, F. “Rail-Flaw Detection:
Decades of NDI Reliability Assessment. A Science That Works.” Railway Track
San Antonio, TX: Karta Technology and Structures. Vol. 86, No. 5. New
(2000). York, NY: Simmons-Boardman (1990):
p 30-32.
22. Hyatt, R.W., G.E. Kechter and
R.G. Menton. “Probability of Detection 33. Grewal, D.S. “Improved Ultrasonic
Estimation for Data Sets with Rogue Testing of Railroad Rail for Transverse
Points.” Materials Evaluation. Vol. 49, Discontinuities in the Rail Head Using
No. 11. Columbus, OH: American Higher Order Rayleigh (M21) Waves.”
Society for Nondestructive Testing Materials Evaluation. Vol. 54, No. 9.
(November 1991): p 1402-1408. Columbus, OH: American Society for
Nondestructive Testing
23. Fahr, A., D.S. Forsyth and M. Bullock. (September 1996): p 983-986.
Report LTR-SMPL-1993-0102,
A Comparison of Probability of Detection 34. Clark, R. and S. Singh. “The Inspection
Data Determined Using Different of Thermite Welds in Railroad Rail —
Statistical Methods. Ottawa, Ontario, A Perennial Problem.” Insight. Vol. 45,
Canada: National Research Council No. 6. Northampton, United
Canada (December 1993). Kingdom: British Institute of
Non-Destructive Testing (June 2003):
24. Fahr, A., D.S. Forsyth, M. Bullock and p 387-393.
W. Wallace. NRCC-LTR-ST-1961, NDT
Techniques for Damage Tolerance–Based 35. Wilcox, P., M. Evans, B. Pavlakovic,
Life Prediction of Aero-Engine Turbine D. Alleyne, K. Vine, P. Cawley and
Disks. Ottawa, Ontario, Canada: M. Lowe. “Guided Wave Testing of
National Research Council Canada Rail.” Insight. Vol. 45, No. 6.
(February 1994). Northampton, United Kingdom:
British Institute of Non-Destructive
25. Spencer, F.W. “Identifying Sources of Testing (June 2003): p 413-420.
Variation for Reliability Analysis of
Field Inspections.” RTO-MP-10, 36. Alers, G.A. Report
AC/323 (AVT) TP/2, RTO Meetings DOT/FRA/ORD-88/09, Railroad Rail
Proceedings 10: Airframe Inspection Flaw Detection System Based on
Reliability under Field/Depot Conditions Electromagnetic Acoustic Transducers.
[Brussels, Belgium]. Neuily-sur-Seine, Washington, DC: United States
France: Research and Technology Department of Transportation (1988).
Organization (1998): p 11·1–11·8.
37. Wooh, S.C. “Doppler-Based Airborne
26. ASME Boiler and Pressure Vessel Code. Ultrasound for Detecting Surface
New York, NY: ASME International. Discontinuities on a Moving Target.”
Research in Nondestructive Evaluation.
Vol. 12, No. 3. Columbus, OH:
American Society for Nondestructive
Testing (2000): p 145-166.

550 Ultrasonic Testing

38. Rose, J.L., M.J. Avioli, P. Mudge and 46. Egle, D.M. and D.E. Bray. “Application
R. Sanderson. “Guided Wave of the Acoustoelastic Effect to Rail
Inspection Potential of Defects in Stress Measurement.” Materials
Rail.” NDT&E International. Vol. 37, Evaluation. Vol. 37, No. 4. Columbus,
No. 2. London, United Kingdom: OH: American Society for
Elsevier (March 2004): p 153-161. Nondestructive Testing (March 1979):
p 41-46, 55.
39. Lanza di Scalea, F., I. Bartoli, P. Rizzo
and J. McNamara. Report 47. Bray, D.E. and D.M. Egle. “Ultrasonic
DOT/FRA/ORD-04/16, On-Line Studies of Anisotropy in Cold-Worked
High-Speed Rail Defect Detection. Layer of Used Rail.” Metal Science.
Washington, DC: United States Vol. 15, No. 11-12. London, United
Department of Transportation (2004). Kingdom: Institute of Metals (1981):
p 574-582.
40. Lanza di Scalea, F., I. Bartoli, P. Rizzo
and M. Fateh. “High-Speed Defect 48. Benyon, J.A. and A.S. Watson. “The
Detection in Rails by Noncontact Use of Monte Carlo Analysis to
Guided Ultrasonic Testing.” Journal of Increase Axle Inspection Interval.”
the Transportation Research Board. Proceedings of the 13th International
Vol. 1916. Washington, DC: Wheelset Congress [Rome, Italy,
Transportation Research Board (2005): September 2001]. Brussels, Belgium:
p 66-77. Union of European Railway Industries,
for the European Railway Wheels
41. Lanza di Scalea, F., P. Rizzo, S. Coccia, Association (2001).
I. Bartoli, M. Fateh, E. Viola and
G. Pascale. “Non-Contact Ultrasonic 49. Hirakawa, K., K. Toyama and
Inspection of Rails and Signal M. Kubota. “The Analysis and
Processing for Automatic Defect Prevention of Failure in Railway
Detection and Classification.” Insight. Axles.” International Journal of Fatigue.
Vol. 47, No. 6. Northampton, United Vol. 20, No. 2. London, United
Kingdom: British Institute of Kingdom: Elsevier (February 1998):
Non-Destructive Testing (June 2005): p 135-144.
p 346-353.
50. Hansen, W. and H. Hintze. “Ultrasonic
42. Rose, J.L., M.J. Avioli and W.-J. Song. Testing of Railway Axles with the
“Application and Potential of Guided Phased Array Technique: Experience
Wave Rail Inspection.” Insight. Vol. 44, during Operation.” Insight. Vol. 47,
No. 6. Northampton, United No. 6. Northampton, United
Kingdom: British Institute of Kingdom: British Institute of
Non-Destructive Testing (June 2002): Non-Destructive Testing (June 2005):
p 353-358. p 358-360.

43. Cawley, P., M.J.S. Lowe, D.N. Alleyne, 51. Bray, D.E., N.G. Dalvi and R.D. Finch.
B. Pavlakovic and P. Wilcox. “Practical “Ultrasonic Flaw Detection in Model
Long Range Guided Wave Testing: Railway Wheels.” Ultrasonics. Vol. 11,
Applications to Pipes and Rail.” No. 2. Guildford, United Kingdom:
Materials Evaluation. Vol. 61, No. 1. Butterworth Scientific (1973): p 66-73.
Columbus, OH: American Society for
Nondestructive Testing (January 2003): 52. Manual of Standards and
p 66-74. Recommendation Practices — Wheel and
Axle Manual — Section G. Washington,
44. McNamara, J., F. Lanza di Scalea and DC: Association of American Railroads
M. Fateh. “Automatic Defect (1998).
Classification in Long-Range
Ultrasonic Rail Inspection Using a 53. Fukuoka, H., H. Toda, K. Hirakawa,
Support Vector Machine-Based ‘Smart H. Sakamoto and Y. Toya.
System.’” Insight. Vol. 46, No. 6. “Acoustoelastic Measurements of
Northampton, United Kingdom: Residual Stresses in the Rim of
British Institute of Non-Destructive Railroad Wheels.” Wave Propagation in
Testing (June 2004): p 331-337. Inhomogeneous Media and Ultrasonic
Nondestructive Evaluation. AMD,
45. Egle, D.M. and D.E. Bray. Report Vol. 62. New York, NY: ASME
DOT/FRA/ORD-77/341, Nondestructive International (1984): p 185-193.
Measurement of Longitudinal Rail
Stresses: Application of the 54. Wallace, R.[D.] “Ultrasonic Testing in
Acousto-Elastic Effect to Rail Stress the Marine Industry.” Nondestructive
Measurement. Washington, DC: United Testing Handbook, second edition:
States Department of Transportation Vol. 7, Ultrasonic Testing. Columbus,
(1977). OH: American Society for
Nondestructive Testing (1991):
p 668-669.

Special Applications of Ultrasonic Testing 551

55. Kessler, L.W. “Acoustic Microscopy: 65. Foster, J.S. and D. Rugar.
Industrial and Electronics “Low-Temperature Acoustic
Applications.” Nondestructive Testing Microscopy.” Transactions on Sonics and
Handbook, second edition: Vol. 7, Ultrasonics. Vol. SU-32. New York, NY:
Ultrasonic Testing. Columbus, OH: Institute of Electrical and Electronics
American Society for Nondestructive Engineers (1985): p 139-151.
Testing (1991): p 797-817, 826-827.
66. Liang, K.K., G.S. Kino and
56. Korpel, A., L.W. Kessler and B.T. Khuri-Yakub. “Material
P.R. Palermo. “Acoustic Microscope Characterization by the Inversion of
Operating at 100 MHz.” Nature. V(z).” Transactions on Sonics and
Vol. 232, No. 5306. Hampshire, United Ultrasonics. Vol. SU-32. New York, NY:
Kingdom: Macmillan (9 July 1971): Institute of Electrical and Electronics
p 110-111. Engineers (1985): p 213-224.

57. Kessler, L.W. “Acoustic Microscopy 67. Weglein, R.D. “Acoustic
Commentary: SLAM and SAM.” 1985 Micro-Metrology.” Transactions on
IEEE Transactions on Sonics and Sonics and Ultrasonics. Vol. SU-32.
Ultrasonics. Vol. SU-32, No. 2. New New York, NY: Institute of Electrical
York, NY: Institute of Electrical and and Electronics Engineers (1985):
Electronics Engineers (1985): p 225-234.
p 136-138.
68. Kushibiki, J. and N. Chubachi.
58. Lemons, R.A. and C.F. Quate. “Material Characterization by
“Acoustic Microscope — Scanning Line-Focus-Beam Acoustic Microscope.
Version.” Applied Physics Letters. Transactions on Sonics and Ultrasonics.
Vol. 24, No. 4. Melville, NY: American Vol. SU-32. New York, NY: Institute of
Institute of Physics (1974): p 163-165. Electrical and Electronics Engineers
(1985): p 189-212.
59. Kessler, L.W. and D.E. Yuhas. “Acoustic
Microscopy.” Proceedings of IEEE. 69. Oishi, M. “Nondestructive Evaluation
Vol. 67, No. 4. New York, NY: Institute of Materials with the Scanning Laser
of Electrical and Electronics Engineers Acoustic Microscope.” IEEE Electrical
(April 1979): p 526-536. Insulation Magazine. Vol. 7, No. 3. New
York, NY: Institute of Electrical and
60. Lin, Z.C., H. Lee, G. Wade, Electronics Engineers, Dielectrics and
M.G. Oravecz and L.W. Kessler. Electrical Insulation Society
“Holographic Image Reconstruction in (May-June 1991).
Scanning Laser Acoustic Microscopy.”
Transactions on Ultrasonics, Ferroelectrics Additional Resources on
and Frequency Control. Vol. UFFC-34, Probability of Detection
No. 3. New York, NY: Institute of
Electrical and Electronics Engineers Anderson, R.T., T.J. DeLacy and
(May 1987) p 293-300. R.C. Stewart. NSAS CR-128946,
Detection of Fatigue Cracks by
61. Yu, B.Y., M.G. Oravecz and L.W Kessler. Nondestructive Testing Methods (March
“Multimedia Holographic Image 1973).Berens, A.P. and P.W. Hovey,
Reconstruction in a Scanning Laser AFWAL-TR-81-4160, Evaluation of NDE
Acoustic Microscope.” Acoustical Reliability Characterization. Wright
Imaging. Vol. 16. New York, NY: Patterson Air Force Base, OH: United
Plenum (1988): p 535-542. States Air Force (1981).

62. Yuhas, D.E., M.G. Oravecz and Forsyth, D.S. and M. Bullock.
L.W. Kessler. “Quantitative Flaw NRCC-LTR-ST-1947, A Comparison of
Characterization by Means of the Probability of Detection Data Determined
Scanning Laser Acoustic Microscope Using Different Statistical Methods.
(SLAM).” Proceedings of IEEE. Vol. 67, Boucherville, Quebec, Canada:
No. 4. New York, NY: Institute of National Research Council Canada
Electrical and Electronics Engineers (December 1993).
(April 1979): p 526-536.
Haviland, G.P. and C. Tiffany. “The USAF
63. Oravecz, M.G. and S. Lees. “Acoustic Aircraft Structural Integrity Program
Spectral Interferometry: A New (ASIP).” Proceedings of the American
Method for Sonic Velocity Institute of Aeronautics and Astronautics
Determination.” Acoustical Imaging. Ninth Annual Meeting and Technical
Vol. 13. New York, NY: Plenum (1984): Display [Washington, DC,
p 397-408. January 1973]. Reston, VA: American
Institute of Aeronautics and
64. Cichanski, F.J. United States Patent Astronautics (1973).
4 866 986, Method and System for Dual
Phase Scanning Acoustic Microscopy
(September 1989).

552 Ultrasonic Testing

Packman, P.F., H.S. Pearson, J.S. Owens
and G.B. Marchese. AFML-TR-68-32,
The Applicability of a Fracture
Mechanics–Nondestructive Testing Design
Criterion (May 1968).

Pettit, D.E. and D.W. Hoeppner.
NASA Contract Report CR NAS 9-11722
LR 25387, Fatigue Flaw Growth and
NDT Evaluation for Preventing Through
Cracks in Spacecraft Tankage Structures.
Washington, DC: National Aeronautics
and Space Administration
(September 1972).

Rummel, W.D., P.H. Todd, Jr., R.A. Rathke
and W.L. Castner. “Detection of
Fatigue Cracks by Nondestructive
Evaluation Methods.” Materials
Evaluation. Vol. 32, No. 10. Columbus,
OH: American Society for
Nondestructive Testing (October 1974):
p 205-212.

Rummel, W.D., P.H. Todd, Jr., S.A. Frecska
and R.A. Rathke. NASA CR-2369, The
Detection of Fatigue Cracks by
Nondestructive Testing Methods
(February 1974).

Rummel, W.D., R.A. Rathke, P.H. Todd, Jr.
and S.J. Mullen. MCR-75-212, NASA
Contract Report NASA-CR-144639, The
Detection of Tightly Closed Flaws by
Nondestructive Testing Methods.
Washington, DC: National Aeronautics
and Space Administration
(October 1975).

Spencer, F. and D. Schurman.
DOT/FAA/CT-92/12, III, Reliability
Assessment at Airline Inspection
Facilities: Vol. 3, Results of an Eddy
Current Inspection Reliability Experiment.
Washington, DC: United States
Department of Transportation
(May 1995).

Yee, B.G.W., F.H. Chang, J.C. Couchman
and G.H. Lemon. NASA CR-134991,
Assessment of NDE Reliability Data.
Washington, DC: National Aeronautics
and Space Administration (1975).

Special Applications of Ultrasonic Testing 553



16

CHAPTER

Ultrasonic Testing Glossary

Stephen D. Hart, Alexandria, Virginia

PART 1. Terms

Introduction amplitude, echo: Vertical height of a
received signal on an A-scan,
Many of the definitions in this glossary measured from base to peak for a
are adapted from the second and third video presentation or from peak to
edition of the Nondestructive Testing peak for a radio frequency
Handbook.1-16 The definitions have been presentation.7
modified to satisfy peer review and
editorial style. For this reason, references analog-to-digital converter: Circuit
at the end of this glossary should be whose input is analog and whose
considered not attributions but output is digital.16
acknowledgments and suggestions for
further reading. angle beam: Ultrasound beam traveling
at an acute angle into a medium. The
The definitions in this Nondestructive angle of incidence or angle of
Testing Handbook volume should not be refraction is measured from the
referenced for tests performed according normal to the entry surface.7,22
to standards, specifications or contracts.
Written procedures should refer to angle of incidence: Included angle
definitions in standards. between the beam axis of the incident
wave and the normal to the surface at
This glossary is provided for the point of incidence.7,21
instructional purposes. No other use is
intended. angle of reflection: Included angle
between the beam axis of the reflected
A wave and the normal to the reflecting
surface at the point of reflection.7,21
acceptance standard: Document defining
acceptable discontinuity size limits.7 angle of refraction: Angle between the
See also standard. beam axis of a refracted wave and the
normal to the refracting interface.7,21
acoustic emission: Transient elastic waves
resulting from local internal angle beam testing: Technique of
microdisplacements in a material. By ultrasonic testing in which
extension, the term also describes the transmission of ultrasound is at an
technical discipline and measurement acute angle to the entry surface.7,21
technique relating to this
phenomenon.16 angle beam transducer: Transducer that
transmits or receives ultrasonic energy
acoustic impedance: Material property at an acute angle to the surface. This
defined as the product of sound may be done to achieve special effects
velocity and density of the material. such as setting up transverse or surface
The relative transmission and waves by mode conversion at an
reflection at an interface are governed interface.7,21
in part by the acoustic impedances of
the materials on each side of the anisotropy: Condition in which
interface.7,22 See also characteristic properties of a medium (velocity, for
acoustic impedance; specific acoustic example) depend on direction in the
impedance. medium.

acoustic microscopy: General term anomaly: Variation from normal material
referring to the use of high resolution, or product quality.10
high frequency ultrasonic techniques
to produce images of features beneath antinode: Point in a standing wave where
the surface of a test object.7 certain characteristics of the wave field
have maximum amplitude.7,21
AE: Acoustic emission method of
nondestructive testing. area linearity: See linearity, area.
array: Group of transducers used for
amplitude linearity: See linearity,
amplitude. source location.16
array transducer: Transducer made up of

several piezoelectric elements
individually connected so that the
signals they transmit or receive may
be treated separately or combined as
desired.7 See also phased array.
artificial discontinuity standard: See
acceptance standard.

556 Ultrasonic Testing

A-scan: One-dimensional display of B-scan: Data presentation technique
ultrasonic signal amplitude as typically applied to pulse echo
function of time or depth in test techniques. It produces a
object. two-dimensional view of a cross
sectional plane through the test
ASNT Recommended Practice object. The horizontal sweep is
No. SNT-TC-1A: See Recommended proportional to the distance along the
Practice No. SNT-TC-1A. test object and the vertical sweep is
proportional to depth, showing the
ASNT: American Society for front and back surfaces and
Nondestructive Testing. discontinuities between.7,22

attenuation coefficient: Factor bubbler: See water column.
determined by the degree of burst, forging: See crack, forging.
diminution in sound wave energy per
unit distance traveled. It is composed C
of two parts, one (absorption)
proportional to frequency, the other calibration, basic: Procedure of
(scattering) dependent on the ratio of standardizing an instrument by using
grain size or particle size to a reference standard.
wavelength.7,23 See also ultrasonic
absorption. calibration reflector: Reflector with a
known dimensioned surface in a
attenuation: (1) Decrease in acoustic specified material, established to
energy over distance. This loss may be provide an accurately reproducible
caused by absorption, leakage, reference level.7 See also reference
reflection, scattering or other material standard.
characteristics. (2) Decrease in signal
amplitude caused by acoustic energy cathode ray: Stream of electrons emitted
loss or by an electronic device such as by a heated filament and projected in
an attenuator.10,16,21 a more or less confined beam under
the influence of a magnetic or electric
attenuator: Device for varying the signal field.7,22
amplitude on an ultrasonic
instrument. Usually calibrated in cathode ray tube: Vacuum tube
decibels.7,21 containing a screen on which
ultrasonic scans may be displayed.
B Used for A-scans or B-scans in the
twentieth century.7
back reflection: Signal received from the
far boundary or back surface of a test certification: With respect to
object.7,21 nondestructive test personnel, the
process of providing written testimony
background noise: Extraneous signals that an individual has met the
caused by random signal sources requirements of a specific practice or
within or exterior to the ultrasonic standard. See also certified and
testing system, including the test qualified.
material.7,21 It has electrical,
mechanical or chemical origins.16 certified: With respect to nondestructive
Sometimes called grass or hash. test personnel, having written
testimony of qualification. See also
baseline: Horizontal trace across the certification and qualification.
A-scan display. It represents time and
is generally related to material characteristic acoustic impedance:
distance or thickness.7 Acoustic impedance typical or
characteristic of a particular material.
beam exit point: See probe index. See acoustic impedance; specific acoustic
beam spread: Widening of the sound impedance.

beam as it travels through a compensator: Electrical matching
medium.21 Specifically, the solid angle network to compensate for electrical
that contains the main lobe of the impedance differences.7,22
beam in the far field.7
bel (B): See decibel. compressional wave: Wave in which
boundary echo: Reflection of an particle motion in the material is
ultrasonic wave from an interface.7,22 parallel to the wave propagation
brittleness: Material characteristic that direction. Also called longitudinal
leads to crack propagation without wave.7
appreciable plastic deformation.10
broad band: Having a relatively wide contact technique: Testing technique in
frequency bandwidth. Used to describe which the transducer face makes direct
pulses that display a wide frequency contact with the test object through a
spectrum and receivers capable of thin film of couplant.7,22
amplifying them.7
contact transducer: Transducer used in
the contact technique.7

Ultrasonic Testing Glossary 557

continuous wave: Wave of constant crystal: See transducer element.
amplitude and frequency. crystal, X-cut: Cut with face

contracted sweep: Misnomer that refers perpendicular to the X-direction of the
to extending the duration of the piezoelectric crystal.7 In a quartz slice
sweep to permit viewing so cut, a thickness mode of vibration
discontinuities or back reflections occurs when the slice is electrically
from deeper in the test object. The stimulated in the X direction.7,22
sweep appears to be compressed.7 crystal, Y-cut: Piezoelectric crystal whose
cut face is perpendicular to the
corner effect: Strong reflection obtained Y direction. In quartz, a transverse
when an ultrasonic beam is directed mode of vibration is obtained when
toward the intersection of two or three the slice is electrically stimulated in
intersecting surfaces.7,22 the Y direction.7,22
crystal mosaic: Multiple crystals mounted
couplant: Substance used between the in the same surface on one holder and
transducer and the contacting surface connected so as to cause all to vibrate
to permit or improve transmission of as one unit.7,22
ultrasonic energy into or from the test C-scan: Presentation technique applied to
object.7,22 acoustic data and displaying an image
of two-dimensional test object with
crack: (1) Break, fissure or rupture, scaled grays or colors representing the
sometimes V shaped in cross section ultrasonic signals. The amplitude
and relatively narrow. By convention, represented in each pixel may be a
a discontinuity is called a crack if it is pulse echo, through-transmission or
at least three times longer than it is pitch catch value calculated from each
wide. (2) Propagating discontinuity A-scan datum.
caused by fatigue, corrosion or stresses cutoff frequency: Upper or lower spectral
such as heat treating or grinding. May response of a filter or amplifier, at
be difficult to detect unaided because which the response is a specified
of fineness of line and pattern (may amount less (usually 3 or 6 dB) than
have a radial or latticed appearance).10 the maximum response.

crack, cold: Crack that occurs after D
solidification, because of high stresses
from nonuniform cooling.10 damping: (1) Limiting the duration or
decreasing the amplitude of
crack, cooling: Crack resulting from vibrations, as when damping a
uneven cooling after heating or hot transducer element.22 (2) Deliberate
rolling. Cooling cracks are usually introduction of energy absorbers to
deep and lie in a longitudinal reduce vibrations.7
direction but are usually not straight.10
damping capacity: Measure of the ability
crack, fatigue: Progressive growth of a of a material to dissipate mechanical
crack that usually develops on the energy.7,23
surface and is caused by the repeated
loading and unloading of the object.10 damping material: Highly absorbent
material used to cause rapid decay of
crack, forging: Crack developed by vibration.7
forging at too low a temperature,
resulting in rupturing of the damping, transducer: Material bonded to
material.10 Also called burst. the back of the piezoelectric element
of a transducer to limit the duration of
crack, hot: Crack that develops before the vibrations.7,21
material has completely cooled, as
contrasted with cold cracks that damping, ultrasonic: Decrease or decay
develop after solidification.10 of ultrasonic wave amplitude
controlled by the instrument or
crack, quenching: During quenching of transducer.
hot metal, rupture produced by more
rapid cooling and contraction of one dead zone: Interval following the initial
portion of a test object than occur in pulse at the surface of a test object to
adjacent portions.10 the nearest inspectable depth.21 Any
interval following a reflected signal
critical angle: Incident angle of the where additional signals cannot be
ultrasound beam where the refracted detected.7
beam is parallel to the surface and
above which a specific mode of
refracted energy no longer exists.7,21

cross coupling: Cross talk.
cross noise: Cross talk.
cross talk: Unwanted signal leakage

(acoustical or electrical) across an
intended barrier, such as leakage
between the transmitting and
receiving elements of a dual
transducer.7,22 Also called cross noise
and cross coupling.
CRT: See cathode ray tube.

558 Ultrasonic Testing

decibel (dB): Logarithmic unit for distance amplitude correction:
expressing relative signal power, such Compensation of gain as a function of
as the loudness of a sound, in time for difference in amplitude of
proportion to the intensity of a reflections from equal reflectors at
reference signal. One tenth of a bel. different sound travel distances.7
Decibel in signal amplitude is twice Refers also to compensation by
that in signal power.16 One decibel electronic means such as swept gain,
equals ten times the base ten time corrected gain, time variable gain
logarithm of the ratio of two powers. and sensitivity time control.7,22

defect: Discontinuity whose size, shape, divergence: Term sometimes used to
orientation or location (1) makes it describe the spreading of ultrasonic
detrimental to the useful service of its waves beyond the near field. It is a
host object or (2) exceeds an function of transducer diameter and
accept/reject criterion of an applicable wavelength in the medium.7 See beam
specification.10,18 Some discontinuities spread.
do not exceed an accept/reject
criterion and are therefore not defects. double-crystal technique: See pitch catch
Compare crack; discontinuity; technique.
indication.10
dual transducer: See send/receive
delamination: Laminar discontinuity, transducer.
generally an area of unbonded
materials.7 dynamic range: Ratio of maximum to
minimum reflective areas that can be
delay line: Material (liquid or solid) distinguished on the display at a
placed in front of a transducer to constant gain setting.7,19
cause a time delay between the initial
pulse and the front surface E
reflection.7,22
echo: Reflected acoustic energy or signal
delayed sweep: See sweep delay. indicating such energy.7
delayed time base: See delayed sweep.
delta effect: Reradiation or diffraction of effective penetration: In a material, the
maximum depth at which a test signal
energy from a discontinuity.22 The can reveal discontinuities.
reradiated energy may include waves
of both the incident mode and electrical noise: Extraneous signals
converted modes (longitudinal and caused by external sources or electrical
transverse).7 interferences within an ultrasonic
delta t (Δt): Duration measured between instrument.21 A component of
two points in time. Also called time background noise.7
differential.
depth compensation: See distance electromagnetic acoustic transducer:
amplitude correction. Transmitting transducer based on the
depth of field: Focal zone. force exerted on a current flowing in a
depth of focus: Focal zone. magnetic field. A receiving transducer
detectability: A measure of the ability to that detects the current produced by
detect signals from small reflectors. moving a conductor in a magnetic
Limited by the signal-to-noise ratio. field.7
diffraction: Deflection of a wavefront
when passing the edge of an EMAT: See electromagnetic acoustic
ultrasonically opaque object.7,22 transducer.
diffuse reflection: Scattered, incoherent
reflections from rough surfaces.7,21 evaluation: Process of deciding the
discontinuity: Interruption in the severity of a condition after an
physical structure or configuration of a indication has been interpreted.
test object. After nondestructive Evaluation determines if the test
testing, a discontinuity indication can object should be rejected or accepted.7
be interpreted to be a flaw or a defect.10 See also indication and interpretation.
Compare defect; indication.
dispersion: In acoustics, variation of wave expanded sweep: Short duration
phase with frequency.7 horizontal sweep positioned to allow
dispersive medium: Medium in which close examination of a signal.7
the propagation velocity depends on
the wave frequency.7

Ultrasonic Testing Glossary 559

F general examination: In personnel
qualification, a test or examination of
false indication: See indication, false. a person’s knowledge, typically (in the
far field: Zone beyond the near field in case of nondestructive test personnel
qualification) a written test on the
front of a plane transducer in which basic principles of a nondestructive
signal amplitude decreases test method and general knowledge of
monotonically in proportion to basic equipment used in that method.
distance from the transducer.7 Also (According to ASNT’s guidelines, the
called the fraunhofer zone. general examination should not
filter: (1) Electrical circuit that leaves a address knowledge of specific
signal unaffected over a prescribed equipment, codes, standards and
range of frequencies and attenuates procedures pertaining to a particular
signal components at all other application.)10
frequencies.10,20 (2) Data analysis
process for treating data files. ghost: Aliasing indication arising from
flat bottom hole: Type of reflector certain combinations of pulse
commonly used in reference repetition frequency and time base
standards. The end (bottom) surface of frequency.7,23 See also wrap around.
the hole is the reflector.7
flaw location scale: Specially graduated grass: See background noise.
ruler that can be attached to an angle grinding crack: Shallow crack formed in
beam transducer to relate the position
of an indication on the display to the the surface of relatively hard materials
actual location of a discontinuity because of grinding heat. Grinding
within the test object.7 cracks typically are 90 degrees to the
flaw: Unintentional anomaly or direction of grinding.10
imperfection. See also defect and group velocity: Speed at which the
discontinuity.10 envelope of an ultrasonic pulse (many
focal zone: Distance before and after the frequencies) propagates through the
focal point in which the intensity medium.7
differs a specified amount (usually
6 dB) from the focal intensity.7 Also H
called depth of field or depth of focus.
focused beam: Sound beam that hardness: Resistance of metal to denting,
converges to a cross section smaller to plastic deformation by bending or
than that of the element. to mechanical deformation by
focused transducer: Transducer that scratching, abrasion or cutting.
produces a focused sound beam.7 Typically measured by indentation.
fraunhofer zone: See far field.
frequency, fundamental: In resonance harmonic: Vibration frequency that is an
testing, the frequency at which the integral multiple of the fundamental
wavelength is twice the thickness of frequency.7,21
the test material.7,22
frequency, pulse repetition: Number of hash: See background noise.
pulses per second.7 heat affected zone: Base metal that was
frequency, test: Nominal ultrasonic wave
frequency used.7,22 not melted during brazing, cutting or
frequency: Number of complete wave welding but whose microstructure and
cycles passing a given point per physical properties were altered by the
second or the number of vibrations heat.10
per second.7 hertz (Hz): Measurement unit of
fresnel field: See near field. frequency, equivalent to one cycle per
fresnel zone: See near field. second.10,17
front surface: First surface of the test horizontal linearity: Measure of
object encountered by an ultrasonic proportionality between positions of
beam.7 indications on the horizontal trace
and the positions of their
corresponding reflectors.

G

gate: (1) Electronic device for selecting
signals in a segment of the trace on an
A-scan display. (2) The interval along
the baseline that is monitored.7

560 Ultrasonic Testing

I L

immersion technique: Test technique in lamb wave: Type of ultrasonic wave
which the test object and the propagation in which the wave is
transducer are submerged in a liquid guided between two parallel surfaces
(usually water) that acts as the of the test object. Mode and velocity
coupling medium.22 The transducer is depend on the product of the test
not usually in contact with the test frequency and the thickness. Plate
object.7 wave.7

impedance, acoustic: See acoustic linearity, amplitude: Constant
impedance. proportionality between the signal
input to the receiver and the
indication: Nondestructive test amplitude of the signal appearing on
equipment response to a reflector, the display of the ultrasonic
requiring interpretation to determine instrument or on an auxiliary
its relevance. Compare crack; defect; display.7,19 Also called vertical linearity.
discontinuity; indication, false.10
linearity, area: Constant proportionality
indication, discontinuity: Visible between the signal amplitude and the
evidence of a material discontinuity. areas of equal discontinuities located
Subsequent interpretation is required at the same depth in the far field.
to determine the indication’s Necessarily limited by the size of the
significance.10 ultrasonic beam and configuration of
the reflector.7
indication, false: Test indication that
originates where no discontinuity logarithmic decrement: Natural
exists in the test object. Compare logarithm of the ratio of the
defect; indication, nonrelevant.10 amplitudes of two successive cycles in
a damped wave train.7
indication, nonrelevant: Indication
possibly caused by an actual longitudinal wave: Wave in which points
discontinuity that does not affect the of same phase lie on parallel plane
usability of the test object (a change of surfaces. 7,23
section, for instance) or that is smaller
than a relevant indication. Compare loss of back reflection: Absence or
indication, false and indication, significant reduction of an indication
relevant.10 from the back surface of the test
object.7,21
indication, relevant: Indication from a
discontinuity (as opposed to a M
nonrelevant indication) requiring
evaluation by a qualified inspector, main bang: See initial pulse.
typically with reference to an manipulator: In immersion testing, a
acceptance standard, by virtue of the
discontinuity’s size, shape, orientation device for angular orientation of the
or location. Compare indication, transducer7,24 and for scanning
nonrelevant.10,19 motion in three axes.
markers: Series of indications on the
initial pulse: Pulse applied to excite the horizontal trace of the display screen
transducer. It is the first indication on to show increments of time or
the screen if the sweep is undelayed. distance.7,21
Also called the main bang. May refer to material noise: Random signals caused by
an electrical pulse or an acoustic the material structure of the test
pulse.7 object.7,21 A component of background
noise.
insonification: Irradiation with sound.7 mechanical properties: Measurable
interface: Physical boundary between two properties of a material related to its
behavior, such as toughness, hardness
adjacent media.7,21 and elasticity. Compare physical
interface synchronization: See interface properties.
mode conversion: Change of ultrasonic
triggering. wave propagation mode upon
interface triggering: Triggering the sweep reflection or refraction at an interface.7
mode converted signal: Unintended
and auxiliary functions from an signal from mode conversion of
interface echo occurring after the primary test angle, due to interaction
initial pulse.7 Also called interface with component geometry such as the
synchronization. signals after back wall signal when
interpretation: Determination of the testing a long narrow bar.
source, significance and relevance of
test indications.10
isotropy: Condition in which significant
medium properties (sound speed, for
example) are the same in all
directions.7

Ultrasonic Testing Glossary 561

mode of vibration: Manner in which an nondestructive examination (NDE):
acoustic wave is propagated, as Another term for nondestructive
characterized by the particle motion in testing. In the utilities and nuclear
the wave21 (transverse, lamb, surface industry, the word examination is
or longitudinal).7 sometimes preferred because testing
can imply performance trials of
model, analytical: Mathematical pressure containment or power
representation of a process or generation systems.10
phenomenon.
nondestructive inspection (NDI):
multiple back reflections: Repetitive Another term for nondestructive
echoes from the far boundary of the testing. In some industries (utilities,
test object.7,21 aviation), the word inspection often
implies maintenance for a component
multiple-echo technique: Technique that has been in service.10
where thickness is measured between
multiple back reflections, minimizing nondestructive testing (NDT):
error from coatings or from changes in Determination of the physical
temperature or contact pressure. condition of an object without
affecting that object’s ability to fulfill
N its intended function. Nondestructive
test methods typically use an
narrow band: Relative term denoting a appropriate form of energy to
restricted range of frequency determine material properties or to
response.7,22 indicate the presence of material
discontinuities (surface, internal or
NDC: Nondestructive characterization. concealed).10
NDE: (1) Nondestructive evaluation.
nonrelevant indication: See indication,
(2) Nondestructive examination. nonrelevant.
NDI: Nondestructive inspection.
NDT: Nondestructive testing. normal incidence: (1) Condition in
near field: Distance immediately in front which the axis of the ultrasonic beam
is perpendicular to the entry surface of
of a plane transducer in which the the test object. (2) Condition where
ultrasonic beam exhibits complex and the angle of incidence is zero.7
changing wavefronts. Also called the
fresnel field or fresnel zone.21 O
neper: Natural logarithm of a ratio of two
amplitudes (equal to 8.686 dB) used as optimum frequency: Probe frequency
a measure of attenuation. Power ratios that provides the highest
are expressed as half the natural signal-to-noise ratio compatible with
logarithm.7 the detection of a specific
nodal points: In angle beam testing, the discontinuity. Each combination of
location of reflections at opposite discontinuity type and material may
surfaces as a wave progresses along a have a different optimum
test object.7 frequency.7,22
noise: Undesired or unintended signals
that tend to interfere with normal orientation: Angular relationship of a
reception or processing of a desired surface, plane, discontinuity or axis to
signal. The origin may be an electric a reference plane or surface.7,21
or acoustic source, small
discontinuities or abrupt changes in oscillogram: Common term for a record
the acoustic properties of the test or photograph of data displayed on
material.7,22 See also signal-to-noise. screen.7,22
noncontact transducer: In ultrasonic
testing, a sensor designed for wave P
propagation through gas.
nondestructive characterization (NDC): parasitic echo: See spurious echo.
Branch of nondestructive testing particle motion: Movement of particles
concerned with the description and
prediction of material properties and of material during wave propagation.7
behavior of components and systems. penetration, ultrasonic: Propagation of
nondestructive evaluation (NDE):
Another term for nondestructive ultrasonic energy into a material.7 See
testing. In research and academic also effective penetration.
communities, the word evaluation is period: Value of the minimum duration
sometimes preferred because it implies after which the same characteristics of
interpretation by knowledgeable a periodic waveform or a periodic
personnel or systems.10 feature repeat.10

562 Ultrasonic Testing

phantom: Reference standard used to pulse repetition frequency: See repetition
verify the performance of diagnostic rate.
ultrasound systems.7
pulse tuning: Control of pulse frequency
phase velocity: Velocity of a single to optimize system response.7
frequency continuous wave.7
Q
phased array: Mosaic of transducer
elements in which the timing of the qualification: Process of demonstrating
elements’ excitation can be that an individual has the required
individually controlled to produce amount and the required type of
certain desired effects, such as steering training, experience, knowledge and
or focusing the beam. abilities.10 See also certification and
qualified.
physical properties: Nonmechanical
properties such as density, electrical qualified: Having demonstrated the
conductivity, heat conductivity and required amount and the required
thermal expansion.10 Compare type of training, experience,
mechanical properties. knowledge and abilities.10 See also
certified and qualification.
piezoelectric effect: Ability of certain
materials to convert electrical energy quality: Ability of a process or product to
(voltage) into mechanical energy meet specifications or to meet the
(stress) and vice versa.7,22 expectations of its users in terms of
efficiency, appearance, reliability and
pitch catch technique: Ultrasonic test ergonomics.10
technique that uses two transducers,
one transmitting and the other quality assurance: Administrative actions
receiving on the same or opposite that specify, enforce and verify
surface.7,21,22 Also called double-crystal quality.10
technique or two-transducer technique.
quality control: Physical and
plane wave: See longitudinal wave. administrative actions required to
plate wave: See lamb wave. ensure compliance with a quality
point of incidence: Point at which the assurance program. Quality control
may include nondestructive testing in
axis of the sound beam leaves the the manufacturing cycle.10
wedge of an angle beam transducer
and enters the test object.7,22 See also R
probe index.
poling: Process of reorienting crystal radian (rad): Measurement unit of plane
domains in certain materials by angle subtending, in a circle, an arc
applying a strong electric field at equal in length to the radius.
elevated temperatures, inducing
macroscopic polarization and radio frequency display: Presentation of
piezoelectric behavior.7 unrectified signals.7,22 See also video
presentation: Technique used to show presentation.
ultrasonic information. This may
include A-scans, B-scans or C-scans, range: Maximum ultrasonic path length
displayed on various types of recorders that is displayed.7 See also sweep
or display instruments.7,21 length.22
primary reference response level:
Ultrasonic response from the basic rarefaction: Thinning or separation of
reference reflector at the specified particles in a propagating medium due
sound path distance, electronically to the decompression phase of an
adjusted to a specified percentage of ultrasonic cycle. Opposite of
full screen height.7 compression. A compressional wave is
probe: See sensor; transducer. composed of alternating compressions
probe index: Point on a transverse wave and rarefactions.7,21
or surface wave transducer through
which the emergent beam axis rayleigh wave: Ultrasonic wave that
passes.7,23 See also point of incidence. propagates along the surface of a test
propagation: Movement of a wave object. The particle motion is elliptical
through a medium.7,21 in a plane perpendicular to the
pulse: Transient electrical or ultrasonic surface, decreasing rapidly with depth
signal that has a rapid increase in below the surface. The effective depth
amplitude to its maximum value, of penetration is considered to be
followed by an immediate return.16 about one wavelength.7 Also called
pulse echo technique: Ultrasonic test surface wave.
technique in which discontinuities are
detected by return echoes from the
transmitted pulses.7
pulse length: Measure of pulse duration
expressed in time or number of
cycles.7,22

Ultrasonic Testing Glossary 563

receiver: (1) Section of the ultrasonic resonance technique: Method using the
instrument that amplifies echoes resonance principle for determining
returning from the test object. speed, thickness or presence of
(2) Transducer that picks up the laminar discontinuities.7
echoes.7
resonant frequency: Frequency at which
recommended practice: Set of guidelines a body vibrates freely after being set in
or recommendations.10 motion by some outside force.7,21

Recommended Practice No. SNT-TC-1A: RF display: See radio frequency display.
Set of guidelines published by the ringing signals: (1) Closely spaced
American Society for Nondestructive
Testing, for employers to establish and multiple signals caused by multiple
conduct a qualification and reflections in a thin material.
certification program for (2) Signals caused by continued
nondestructive testing personnel.10 vibration of a transducer.7,22
ringing technique: Test technique for
reference standard: (1) Test object bonded structures in which unbonds
containing known reflectors are indicated by increased amplitude
representing accept or reject criteria. of ringing signals.7,22
(2) Sample test object selected for ringing time: Time that the mechanical
reference. vibrations of a transducer continue
after the electrical pulse has
refracted beam: Beam transmitted in the stopped.7,22
second medium when an ultrasonic roof angle: In a dual-element delay line
beam is incident at an acute angle on transducer, the tilt angle by which the
the interface between two media transducer elements of the delay line
having different sound speeds.7,22 are oriented to direct the beams of the
two elements to intersect at a specified
refraction: Change in direction of an zone in the medium.7
acoustic wave as the ultrasonic beam
passes from one medium into another S
having different acoustic speeds. A
change in both direction and mode SAM: scanning acoustic microscope.
occurs at acute angles of incidence. At saturation: Condition in which high
small angles of incidence, the original
mode and a converted mode may exist amplitude signals on a display screen
simultaneously in the second do not increase with increased gain
medium.7 and appear flattened.7
scanning: Movement of the transducer
refractive index: Ratio of the speed of the over the surface of the test object in a
incident wave to that of a refracted controlled manner so as to achieve
wave. It is known as the refractive complete coverage. May be either a
index of the second medium with contact or immersion technique.7
respect to the first.7 scattering: Uncontrolled reflection of
ultrasonic waves by small
reject: Minimize or eliminate low discontinuities or surface
amplitude signals (such as electrical or irregularities.7
material noise) so that other signals schlieren system: Optical system used for
may be further amplified. This control visual display of an ultrasonic beam
can reduce vertical linearity.7 Also passing through a transparent
called suppression.22 medium.7,22
search unit: See transducer.
rejection level: Level above or below self-coupling transducer: Contact
which a signal is an indication of a transducer that allows testing with a
rejectable discontinuity.7,22 liquid couplant.
send/receive transducer: Transducer
relevant indication: In nondestructive consisting of two piezoelectric
testing, an indication from a elements mounted side by side
discontinuity requiring evaluation.7 separated by an acoustic barrier. One
element transmits; one receives.7,21
repetition rate: Number of pulses sensitivity: Ability of signal to change
generated or transmitted per unit of with small changes of measured
time (usually seconds).7 quantity.
sensor: Device that detects a material
resolving power: Measure of the ability of property or mechanical behavior (such
an ultrasonic system to separate two as radiation or displacement) and
signals close together in time or converts it to an electrical signal.
distance.7,21 Probe; transducer.

resonance: Condition in which the
frequency of a forcing vibration
(ultrasonic wave) is the same as the
natural vibration frequency of the
propagation body (test object),
possibly resulting in large amplitude
vibrations.7,21

564 Ultrasonic Testing

shadow: Region in a test object that standard: (1) Reference object used as a
cannot be reached by ultrasonic basis for comparison or calibration.
energy traveling in a given direction. (2) Concept established by authority,
Shadows are caused by geometry or custom or agreement to serve as a
the presence of intervening large model or rule in the measurement of
discontinuities.7 quantity or the establishment of a
practice or procedure.7,22
shear wave: See transverse wave.
shoe: Device used to adapt a straight standing wave: Wave in which the
energy flux is zero at all points. Such
beam transducer for use in a specific waves result from the interaction of
type of testing, including angle beam similar waves traveling in opposite
or surface wave tests and tests on directions as when reflected waves
curved surfaces.7,22 See also wedge. meet advancing waves. A particular
SH wave: Transverse horizontal wave. case is that of waves in a body whose
SI (International System of Units): thickness is an integral multiple of
Measurement system using decimals in half-wavelengths, as in resonance
which the following seven units are testing.7,21,22
considered basic: meter, mole,
kilogram, second, ampere, kelvin and stiffness: Slope of curve of stress to strain,
candela.10,17 described by Young’s modulus of
signal: Physical quantity, such as elasticity. Compare hardness.
electrical voltage, that contains
information.10,20 straight beam: Ultrasonic wave traveling
signal-to-noise ratio: Ratio of signal normal to the test surface.7,22
amplitude (responses that contain
information) to baseline noise suppression: See reject.
amplitude (responses that contain no surface wave: See rayleigh wave.
information). See also noise.10,20 SV wave: Shear vertical wave.
skip distance: In angle beam tests of plate sweep: Uniform and repeated movement
or pipe, the distance from the sound
entry point to the exit point on the of a spot across the display screen to
same surface after reflection from the form the horizontal baseline.7 Also
back surface.7 Also called V path.22 called time base.
Snell’s law: Physical law that defines the sweep delay: (1) Delay in time of starting
relationship between the angle of the sweep after the initial pulse.
incidence and the angle of refraction. (2) Control for adjusting the time.7,22
SNR: See signal-to-noise ratio. Also called time delay.
SNT-TC-1A: See Recommended Practice sweep length: Length of time or distance
No. SNT-TC-1A. represented by the horizontal baseline
specific acoustic impedance: Acoustic on an A-scan.7,22
impedance in a particular test object
or a defined volume of a specified T
material. See also acoustic impedance;
characteristic acoustic impedance. test surface: Surface of the test object at
specification: Set of instructions or which the ultrasonic energy enters or
standards invoked by a specific is detected.7
customer to govern the results or
performance of a specific set of tasks threshold: Voltage level setting of an
or products.10 instrument that causes it to register
spectrum: Amplitude distribution of only signals greater or less than a
frequencies in a signal.7 specified magnitude.10,20 This
spectrum response: Amplification (gain) threshold may be adjustable, fixed or
of a receiver over a range of floating.16
frequencies.7
spherical wave: Wave in which points of through-transmission technique: Test
the same phase lie on surfaces of technique in which ultrasonic energy
concentric spheres.7,23 is transmitted through the test object
spurious echo: General term denoting and received by a second transducer
any indication that cannot be on the opposite side. Changes in
associated with a discontinuity or received signal amplitude are taken as
boundary at the location displayed.7 indications of variations in material
Also called parasitic echo. continuity.7
squint angle: Angle by which the
ultrasonic beam axis deviates from the time base: See sweep.
probe axis.7 time delay: See sweep delay.
squirter: See water column. time differential: See delta t.
time of flight: Time for an acoustic wave

to travel between two points. For
example, the time required for a pulse
to travel from the transmitter to the
receiver via diffraction at a
discontinuity edge or along the surface
of the test object.7

Ultrasonic Testing Glossary 565

tone burst: Wave train consisting of transverse vertical (polarized) wave:
several cycles of the same frequency.7 Transverse wave in which the plane of
vibration is normal to the incidence
transducer: (1) Device that converts surface.7
mechanical energy to electrical output
or vice versa. (2) Piezoelectric device transverse wave: Type of wave in which
that converts attributes of the the particle motion is perpendicular to
stress-strain field of an acoustic wave the direction of propagation.7,22 Also
into an electrical signal of voltage called shear wave.
versus time. Sensor; probe.16
transverse wave transducer: Transducer
transducer, differential: Piezoelectric that generates transverse waves in a
twin-element or dual-pole transducer, test object.
the output poles of which are isolated
from the case and are at a floating two-transducer technique: See pitch catch
potential.16 technique.

transducer element: In an ultrasonic U
transducer, the piezoelectric crystal to
be coupled to the test surface. Also ultrasonic absorption: Damping or
called the crystal. dissipation of ultrasonic waves as they
pass through a medium.7,21 See also
transducer, flat response: Transducer attenuation coefficient.
whose frequency response has no
resonance or characteristic response ultrasonic spectroscopy: Analysis of the
within its specified frequency band.16 frequency content of an acoustic
wave. Generally performed
transducer relative sensitivity: Response mathematically using a fast fourier
of the transducer to a given source.16 transform.7

transducer, resonant: Transducer that ultrasonic spectrum: Usually the
uses the mechanical amplification due frequency range from 20 kHz to
to a resonant frequency (or several 50 MHz but may extend much higher
close resonant frequencies) to give in special applications.7
high sensitivity in a narrow band,
typically ±10 percent of the principal ultrasonic: Of or relating to acoustic
resonant frequency at the –3 dB vibration frequencies greater than
points.16 about 20 kHz.7,22

transducer, single-ended: Piezoelectric ultrasonic testing: Method of
single-element transducer, the output nondestructive testing, using acoustic
pole of which is isolated from the waves at inaudibly high frequencies at
case, the other pole being at the same the interrogating energy.
potential as the case.16
UT: Abbreviation for the ultrasonic
transducer, wide band: Transducer whose method of nondestructive testing.7,22
response to surface displacements is
flat over a wide frequency range. V

transfer function: Description of changes vertical limit: Maximum useful readable
to the waves arising as they propagate level of vertical indication on an
through the medium or, for a A-scan.7
transducer, the relationship between
the transducer output signal and the vertical linearity: See linearity, amplitude.
physical parameters of the acoustic video presentation: Display presentation
wave at the transducer.16
in which radiofrequency signals have
transmission angle: Incident angle of a been rectified and usually filtered.7,22
transmitted ultrasonic beam. It is zero V path: See skip distance.
degrees when the beam is
perpendicular (normal) to the test
surface.7,21

transmission characteristics: Test object
characteristics that influence the
passage of ultrasonic energy, including
scattering, attenuation or surface
conditions.7

transmission technique: See
through-transmission technique.

transmitter: (1) Transducer that emits
ultrasonic energy. (2) Electrical circuits
that generate the signals emitted by
the transducer.7

transverse horizontal (polarized) wave:
Transverse wave in which the particle
vibration is parallel to the incidence
surface.7

566 Ultrasonic Testing

W

water column: Tube filled with water and
attached to the front of a transducer
to couple an ultrasonic beam to a test
object. A delay line between the initial
pulse and the front surface signal. Also
serves as a coupling device.7 See also
delay line.

water jet: Unsupported stream of water
carrying ultrasonic signals between the
transducer and the test object surface.7
Also called a squirter or water column.

water path: In immersion testing or with
a water column, the distance from the
transducer face to the test object’s
front surface.7,22

wave interference: Production of a series
of maxima and minima of sound
pressure as a consequence of the
superposition of waves having
different phases.7,22

wave train: Series of waves or groups of
waves passing along the same course
at regular intervals.7

wavefront: In a wave disturbance, the
locus of points having the same
phase.7,22

waveguide: Device to transmit elastic
energy from a test object to a remote
transducer — for example, a wire
joined at one end to a test object and
at the other end to a transducer.

wavelength: Distance needed in the
propagation direction for a wave to go
through a complete cycle.7,21

wear face: Protective material on the face
of a transducer to prevent wear of the
piezoelectric element.7,22

wedge: Device used to direct ultrasonic
energy into a test object at an acute
angle.7,22 See also shoe.

wheel transducer: Device that couples
ultrasonic energy to a test object
through the rolling contact area of a
wheel containing a liquid and one or
more transducers.7,22

wrap around: Display of misleading
ultrasonic reflections from a
previously transmitted pulse because
of excessive pulse repetition
frequency.7,24 See also ghost.

Ultrasonic Testing Glossary 567

PART 2. Symbols

c = speed of sound in air (meter per
second)

D = diameter (meter)
dB = decibel

E = Young’s modulus of elasticity
f = frequency (hertz)
R, r = reflection coefficient
T = transmission coefficient
t = time (second)
V = volt
v = velocity (meter per second)
Z = impedance (pascal second per

meter)
α = attenuation
ε = strain
λ = wavelength (meter)
θ = angle (radian)
ρ = density (kilogram per cubic meter)
σ = Poisson’s ratio; stress (pascal)

568 Ultrasonic Testing

References

1. Nondestructive Testing Handbook, 13. Nondestructive Testing Handbook, third
second edition: Vol. 1, Leak Testing. edition: Vol. 3, Infrared and Thermal
Columbus, OH: American Society for Testing. Columbus, OH: American
Nondestructive Testing (1982). Society for Nondestructive Testing
(2001).
2. Nondestructive Testing Handbook,
second edition: Vol. 2, Liquid Penetrant 14. Nondestructive Testing Handbook, third
Tests. Columbus, OH: American edition: Vol. 4, Radiographic Testing.
Society for Nondestructive Testing Columbus, OH: American Society for
(1982). Nondestructive Testing (2002).

3. Nondestructive Testing Handbook, 15. Nondestructive Testing Handbook, third
second edition: Vol. 3, Radiography and edition: Vol. 5, Electromagnetic Testing.
Radiation Testing. Columbus, OH: Columbus, OH: American Society for
American Society for Nondestructive Nondestructive Testing (2004).
Testing (1985).
16. Nondestructive Testing Handbook, third
4. Nondestructive Testing Handbook, edition: Vol. 6, Acoustic Emission
second edition: Vol. 4, Electromagnetic Testing. Columbus, OH: American
Testing. Columbus, OH: American Society for Nondestructive Testing
Society for Nondestructive Testing (2005).
(1986).
17. IEEE Standard Dictionary of Electrical
5. Nondestructive Testing Handbook, and Electronic Terms. New York, NY:
second edition: Vol. 5, Acoustic Wiley-Interscience, for the Institute of
Emission Testing. Columbus, OH: Electrical and Electronics Engineers
American Society for Nondestructive (1984).
Testing (1987).
18. API RP 5A5, Recommended Practice for
6. Nondestructive Testing Handbook, Field Inspection of New Casing, Tubing,
second edition: Vol. 6, Magnetic Particle and Plain End Drill Pipe, sixth edition.
Testing. Columbus, OH: American Washington, DC: American Petroleum
Society for Nondestructive Testing Institute (1999).
(1989).
19. Annual Book of ASTM Standards:
7. Nondestructive Testing Handbook, Section 3, Metals Test Methods and
second edition: Vol. 7, Ultrasonic Analytical Procedures. Vol. 03.03,
Testing. Columbus, OH: American Nondestructive Testing. West
Society for Nondestructive Testing Conshohocken, PA: ASTM
(1991). International (2001).

8. Nondestructive Testing Handbook, 20. ASTM E 268-81, Definitions Approved
second edition: Vol. 8, Visual and for Use by Agencies of the Department of
Optical Testing. Columbus, OH: Defense as Part of Federal Test Method
American Society for Nondestructive Standard No. 151b and for Listing in the
Testing (1993). DoD Index of Specifications and
Standards. West Conshohocken, PA:
9. Nondestructive Testing Handbook, ASTM International (1981).
second edition: Vol. 9, Special
Nondestructive Testing Methods. 21. Weismantel, E.E. et al. “Glossary of
Columbus, OH: American Society for Terms Frequently Used in
Nondestructive Testing (1995). Nondestructive Testing.” Materials
Evaluation. Vol. 33, No. 4. Columbus,
10. Nondestructive Testing Handbook, OH: American Society for
second edition: Vol. 10, Nondestructive Nondestructive Testing (April 1975):
Testing Overview. Columbus, OH: p 42A-44A.
American Society for Nondestructive
Testing (1996). 22. TO33B-1-1 (NAVAIR 01-1A-16)
TM43-0103, Nondestructive Testing
11. Nondestructive Testing Handbook, third Methods. Washington, DC: United
edition: Vol. 1, Leak Testing. States Department of Defense, United
Columbus, OH: American Society for States Air Force (June 1984): p 1.25.
Nondestructive Testing (1998).

12. Nondestructive Testing Handbook, third
edition: Vol. 2, Liquid Penetrant Testing.
Columbus, OH: American Society for
Nondestructive Testing (2000).

Ultrasonic Testing Glossary 569

23. “Ultrasonic Flaw Detection.” The
Glossary of Terms Used in Nondestructive
Testing. British Standard 3683, Part 4.
London, England: British Standards
Institute (1985). Superseded by EN
1330-4, Nondestructive Terminology:
Part 4, “Terms Used in Ultrasonic
Testing.” Brussels, Belgium: European
Committee for Standardization (2000).

24. MIL-STD-371, Glossary of Terms and
Definitions for Ultrasonic Testing
Procedures. Washington, DC: United
States Department of Defense, United
States Army (October 1987).

570 Ultrasonic Testing

Index

A advanced materials, 357
ultrasonic testing of adhesive bonds, 369-379
aboveground storage tanks ultrasonic testing of advanced structural ceramics, 358-368
ultrasonic testing, 439 ultrasonic testing of composite laminates, 380-390

acceptance/rejection criteria, 15, 16, 429 aeronautics
and tolerable surface conditions, 401 ultrasonic testing applications, 516-525
ultrasonic inservice inspection in electric power plants, 459
ultrasonic testing of piping, 436 aerospace applications. See also aircraft
ultrasonic testing of storage tanks, 439 acoustic microscope applications, 192
combined ultrasonic scanning of welds, 92-93
acoustic emission testing, 10 lamb wave applications, 100
early development of, 29 laser ultrasonic inspection applications, 112
for materials characterization, 309 material test issues, 495
ultrasonic inservice inspection of aircraft, 507-515
acoustic holography, 29, 300-301 ultrasonic material production inspection, 499-506
acoustic impedance, 61 ultrasonic testing, 493-525
ultrasonic testing of space systems and aeronautics, 516-525
and air coupled transducers, 496
common materials, 496, 497 aging
couplants for ultrasonic contact testing, 223 and nuclear power plant life, 465
and elastic anisotropy, 325 piezoelectric materials, 66
at grain boundaries, 324 ultrasonic testing of highway bridges, 476
importance in ultrasonic testing, 262 ultrasonic testing of space system wiring insulation, 519-521
plastic wedges for ultrasonic transducers, 75
straight beam pulse echo tests, 202 air
weld metal, 118 acoustic parameters, 43
acoustic lenses, 95, 296-298 sound attenuation in, 130
acoustic methods, 12 sound velocity in, 129
acoustic microscopy, 99, 298-299 ultrasonic interface transmission and reflection coefficients, 497
acoustic microscopes, 544-548
instrumentation, 185, 192 air coupled transducers, 129-130
for ultrasonic materials characterization, 315-316 advantages and limitations of, 501
acoustics ceramic, 131
history of discoveries, 24-25 electrostatic, 131
origins of practical ultrasonics, 25-26 high frequency, 131-132
parameters of typical materials, 43 low frequency, 130-131
units for, 31-32
acoustic velocity aircraft. See also aerospace applications
typical materials, 43 composite materials in, 500
acoustoelasticity, 321-322 fatigue cracking of fuselage, 3
acoustooptics, 26-27 focused ultrasonic transducers for aluminum, 95
acoustoultrasonics, 314 guided wave ultrasonic inspection, 105-106
damage assessment of nickel alloy space system turbine, 524-525 laser ultrasonic inspection, 112
testing for mechanical properties, 338-342 ultrasonic immersion testing interpretation of indications from rotor
acrylic resin wheel, 280-283
acoustic parameters, 43
acrylics airy disk of the first order, 97-98
ultrasonic interface transmission and reflection coefficients, 497 alarm threshold controls, 187, 188
ultrasonic wavelength, 497 alumina
wedges for angle beam transducers, 75-77
adhesive bonds. See also bond testing transfer curve of monolithic, 361, 362
acoustoultrasonic testing, 340 aluminum
characteristics, 369
pulse echo contact ultrasonic testing, 215-216 bibliography, 424
ultrasonic testing, 369-379 acoustic parameters of galvanized, 43
angle beam contact surface wave testing, 220
angle beam ultrasonic immersion testing for corrosion, 295
dispersion in waveguides, 102, 103, 104
focused beam ultrasonic tests of laminates, 299
focused ultrasonic transducers for airframes, 95

immersion ultrasonic testing indications, 275, 276 anisotropic materials
straight beam pulse echo contact tests, 205 piezoelectrics, 62
ultrasonic characterization of grain size, 328 ultrasonic materials characterization, 319
ultrasonic immersion testing interpretation of indications from rotor ultrasonic testing of composite laminates, 284
ultrasonic testing of wood structures, 477
wheels, 280-283 ultrasonic wave propagation in, 40
ultrasonic interface transmission and reflection coefficients, 497
ultrasonic testing of adhesive bonds on, 370, 371, 373-376 Annual Book of ASTM Standards, 16
ultrasonic testing of primary, 406-417 annular phased transducer arrays, 229, 238, 418
ultrasonic wavelength, 497
ultrasound attenuation in, 407-409 operation, 245-248
aluminum alloys ANSI/ASNT CP-189, 17, 21
immersion ultrasonic testing indications, 276, 277 apodization, 150
laser ultrasonic monitoring of annealing, 113 area amplitude calibration blocks
as replacement for steel and iron, and need for nondestructive testing, 3
aluminum alloy UNS A92219 for ultrasonic test equipment, 195-196, 198
probability of detection curve for ultrasonic testing of welds, 511530 arrays. See phased arrays
aluminum alloy UNS A97029
ultrasonic attenuation in, 407, 409 for primary metals, bibliography, 424
aluminum alloy UNS A97075 artificial discontinuities
ultrasonic inservice testing of exfoliation corrosion in aircraft, 513
ultrasonic inservice testing of stress corrosion cracking in aircraft, 511-512 for ultrasonic inservice testing of aircraft, 507
aluminum alloy UNS A97079 for ultrasonic testing of ingots, 401
ultrasonic inservice testing of stress corrosion cracking in aircraft, 511 artificial intelligence
aluminum copper alloy ultrasonic signal processing applications, 172
ultrasonic hardness measurement, 333 A-scan ultrasonic equipment, 179-180, 264
aluminum uranium alloy aerospace applications, 498
acoustic parameters, 43 butt weld imaging, 225
American Bureau of Shipping calibration, 194
ABS 30, 17 discontinuity sensitivity, 179-180
standards for ultrasonic testing, 17 fossil plant boiler testing, 467
American Petroleum Institute (API) immersion testing of composite tubing, 286, 287
API 5CT, 442 not directly suitable for structural concrete, 481
API 620, 439 phased array application, 241
API 650, 439 and pulse echo immersion test parameters, 271
API 653, 439 pulse echo test systems, 182
API RP 5A5, 441, 443 receiver gain adjustment, 187
API RP 5UE, 17 synthetic aperture focusing, 486
API RP 2X, 17 ASME [American Society of Mechanical Engineers], 17
API SPEC 6A, 17 ASME B31.3, 436
API SPEC 5L, 17 ASME Boiler and Pressure Vessel Code, 17, 439
standards for ultrasonic testing, 17 ASME calibration blocks, 196, 197
American Society for Nondestructive Testing (ASNT), 16-17 ASNT. See American Society for Nondestructive Testing
ANSI/ASNT CP-189, 17, 21 ASNT Central Certification Program (ACCP), 21
ASNT Central Certification Program (ACCP), 21 ASNT Recommended Practice No. SNT-TC-1A, 16, 17, 21-22
ASNT Recommended Practice No. SNT-TC-1A, 17, 21-22, 439 ASTM International, 16
ASNT Recommended Practice No. SNT-TC-1A, 16, 17, 21-22 ASTM A 388, 18
American Society of Mechanical Engineers. See ASME ASTM A 418, 18
American Welding Society (AWS) ASTM A 435, 18
AWS C3.8, 17 ASTM A 503, 18
AWS G1.2, 17 ASTM A 939, 18
standards for ultrasonic testing, 17 ASTM A 531M, 18
amplifiers ASTM A 577M, 18
external receiver preamplifiers for ultrasonic testing, 8-85, 82 ASTM A 578M, 18
radiofrequency for ultrasonic testing application, 87 ASTM A 609M, 18
ultrasonic pulse echo test systems, 180, 182-183 ASTM A 745M, 18
ultrasonic spectroscopy application, 159 ASTM A 898M, 18
video for ultrasonic testing application, 87, 89 ASTM B 548, 18
amplitude, 36. See also gating ASTM B 594, 18
analog filtering, 150 ASTM B 773, 18
analog signals, 146 ASTM C 133, 18
analog gates, 150, 159 ASTM C 1332, 18
analog spectrum analyzers ASTM D 4883, 18
ultrasonic spectroscopy application, 159 ASTM D 6132, 18
analog-to-digital converters ASTM E 114, 18
in general purpose ultrasonic test equipment, 188 ASTM E 127, 18
synthetic aperture focusing ultrasonic testing, 251 ASTM E 164, 18
ultrasonic testing application, 88, 89, 147-149 ASTM E 213, 18
angle beam pulse echo contact testing, 217-220 ASTM E 214, 18
transducer shoes for, 221 ASTM E 273, 18
verification of transverse wave angle, 217 ASTM E 317, 18, 401
angle beam transducers, 74-77, 179 ASTM E 428, 18
ultrasonic field testing of bridges, 478, 479-480 ASTM E 494, 18
angle beam ultrasonic immersion techniques, 289-295 ASTM E 587, 18
interpretation of results, 291-292 ASTM E 588, 18
ultrasonic backscattering, 293-295 ASTM E 664, 18
angular frequency, 36, 37 ASTM E 797, 18
ASTM E 1001, 18
ASTM E 1065, 18
ASTM E 1158, 18
ASTM E 1315, 18
ASTM E 1324, 18
ASTM E 1454, 18
ASTM E 1495, 18
ASTM E 1774, 18
ASTM E 1816, 18

572 Ultrasonic Testing

ASTM E 1901, 18 bolts
ASTM E 1961, 18 ultrasonic inservice testing of aircraft cadmium plated steel, 512
ASTM E 1962, 18 ultrasonic testing in chemical and petroleum applications, 434
ASTM E 2001, 18 ultrasonic testing of fossil plant turbine high temperature bolts, 471-472
ASTM E 2192, 18
ASTM E 2223, 18 bonded joints
ASTM E 2373, 18 material test issues in aerospace applications, 495
ASTM E 2375, 18
ASTM F 1512, 18 bonded parts
ultrasonic testing standards published by, 18 material production inspection in aerospace applications, 505-506
asymmetric lamb waves, 100
attenuation, of ultrasonic waves, 39 bond reference standards, 515
advanced structural ceramics, 360-361 bond strength, adhesive bonds, 369
in air, 130 bond testers, 193, 505
in air coupled transducers, 132 bond testing. See also adhesive bonds
in concrete, 481
composite laminates, 382 focused beam ultrasonic tests, 299
and mechanical property characterization, 331-337 pulse echo contact ultrasonic testing of adhesive, 215-216
and microstructure characterization, 325, 326-327 tandem ultrasonic transducer application, 233
spectra, 311 ultrasonic inservice inspection of aircraft, 514-515
attenuation coefficient, 326 ultrasonic testing in marine industry, 542
attenuation factor, rayleigh waves, 44 ultrasonic testing of adhesive bonds, 369-379
attenuators, ultrasonic testing application, 86, 183 boot attachment device, for ultrasonic immersion testing, 269
AudigageTM, 29 borescope, 7
austenitic steel brass
acoustic parameters, 43 acoustic parameters of naval, 43
laser ultrasonic thickness gaging in seamless tubes, 111 ultrasonic inservice inspection of condensers in power plants, 459
ultrasonic testing of cladding with electromagnetic acoustic ultrasonic testing of heat exchanger tubing in processing plants, 436
bridges, See highway bridges
transducers, 120-121 Bridge Welding Code, 477
ultrasonic testing of welds with dual-element transducers, 235 broad band instrumentation, 182-183
ultrasonic testing of welds with electromagnetic acoustic transducers, 118- bronze
acoustic parameters of phosphor (5 percent), 43
120 B-scan ultrasonic equipment, 180-181, 264
autocorrelation, 151-152 angle beam immersion ultrasonic systems, 291
autocorrelation coefficient, 151 bonded joints, 505
automatic pattern recognition discontinuity detectability, 181
internal rotary ultrasonic testing, 429
ultrasonic signal processing application, 164 material production inspection in aerospace applications, 502
averaging procedures, 151 phased array application, 241
axles for storage tank testing, 439
synthetic aperture focusing, 486
ultrasonic testing of railroad, 538-540 bubbler ultrasonic testing systems, 267-268, 500
advantages and limitations of, 501
B buffer rods, for ultrasonic contact testing, 222
buildings
backscattering, of ultrasound, See ultrasonic backscattering ultrasonic testing of wood and structural steel, 476, 477
back surface reflection amplitude, 271-272 bursts
ultrasonic tests of steel and wrought alloys, 400
loss of back surface reflection, 275-276 butt welds
and straight beam contact tests, 205 pulse echo contact ultrasonic testing, 225-228
band pass filtering, 187 ultrasonic testing in marine industry, 542
barium titanate
piezoelectric material, 60 C
bars
ultrasonic immersion testing systems, 402-403 cable stayed bridge
ultrasonic testing immersion indication formation, 276 ultrasonic testing, 476
ultrasonic testing in marine industry, 541
ultrasonic testing of aluminum, 406 cadmium plated steel bolts
base units, 30 ultrasonic inservice testing of aircraft, 512
beam collimation, in angle beam immersion ultrasonic systems, 290-291
beam focusing calibration
in linear phased arrays, 242-243 instrumentation for aluminum testing, 414-415
beams ultrasonic testing instrumentation, 194-198
ultrasonic testing of wood and structural steel, 476
beam steering, 90, 421 calibration blocks, ultrasonic. See also reference standards
in linear phased arrays, 242 for angle beam contact testing, 217
bearings for ultrasonic testing applications in metals, 410, 411, 414
ultrasonic testing of highway bridge, 476 for ultrasonic testing in electric power applications, 467
bel (B), 32 for ultrasonic testing systems, 195-198
beryllium
acoustic parameters, 43 capacitance
biconcave lenses, 96-97, 297 in equivalent circuit of piezoelectric element, 66, 67
birefringence, 321
birefringent coefficient, 321 carbon fiber reinforced polymer composites
bituminous asphaltic concrete material production inspection in aerospace applications, 499-503
ultrasonic testing of structural, 481
boilers carbon fiber reinforced silicon carbide
effect of discontinuities, 3 ultrasonic testing, 365, 367
ultrasonic inservice inspection of boiler tubes in power plants, 458-459
ultrasonic testing of fossil plant boilers, 466-468 carbon molybdenum stainless steel
boiling water nuclear reactors ultrasonic testing of fossil plant boiler tubing, 466
ultrasonic testing, 461-462 ultrasonic testing of fossil plant steam lines and headers, 469
ultrasonic testing of piping, 463-464
carbon molybdenum steel
ultrasonic testing of fossil plant boiler tubing, 466

carbon steel
pulse echo contact imaging of butt welds, 227
ultrasonic inservice inspection of boiler tubes in power plants, 458
ultrasonic testing of fossil plant boiler tubing, 466
ultrasonic testing of fossil plant steam lines and headers, 469
ultrasonic toughness measurement, 334
ultrasonic yield strength measurement, 332

Index 573

carbon-to-carbon structures ultrasonic mechanical property characterization, 336-337
material test issues in aerospace applications, 495 ultrasonic spectroscopy of Space Station flywheel rotors, 521-522
ultrasonic assessment of impact damage to space shuttle thermal ultrasonic testing of space systems for fatigue and thermal
protection, 522-523
ultrasonic material inspection in aerospace applications, 504 damage, 516-519
composite tubing
carriage, ultrasonic immersion system, 413-414
castings ultrasonic immersion testing, 285-288
compressional waves, 482
bibliography, 424 concealed cut, See ply gap
material production inspection in aerospace applications, 504 concrete
material test issues in aerospace applications, 495
ultrasonic testing in marine industry, 542 moisture and curing conditions, 483-485
ultrasonic tests with closely positioned transducers, 236 ultrasonic testing of highway bridge, 476, 477
cast iron ultrasonic testing of structural, 481-487
ultrasonic mechanical property characterization, 331 ultrasonic wave speed in, 481, 483
cellulose gums condensers
couplants for ultrasonic contact testing, 223 in power plants, 459
central certification, 22 ultrasonic testing of fossil power plant turbine, 472
cepstrum processing confined space, 22
ultrasonic spectroscopy application, 162 consultants
ceramics for managing ultrasonic testing programs, 14
acoustic microscopy, 548 contact ultrasonic testing systems, 179, 262, 299
air coupled transducers, 131 continuous girder bridge
piezoelectric materials, 60 ultrasonic testing, 476
ultrasonic material characterization, 322 continuous time fourier transform, 145-146
ultrasonic testing of advanced structural, 358-368 continuous wave bond testers, 193
ultrasonic testing of green state, 358-359 continuous wavelet transform, 162
ultrasonic testing of sintered, 359-362 continuous wave phase comparison techniques, 193
certification, 16-22 contoured surfaces
CGS (centimeter-gram-second) units, 30 contoured ultrasonic transducer shoes to fit, 221
characteristic length, and fracture toughness, 333 laser ultrasound advantages, 107
chemical and petroleum applications, 427 sonic position encoding device, 210
internal rotary ultrasonic testing, 429-430 ultrasonic immersion testing interpretation, 277-278
ultrasonic inservice testing of offshore structures, 444-453 convolution
ultrasonic testing in chemical and petroleum industry, 428-431 ultrasonic signal processing application, 149, 153-154
ultrasonic testing in processing plants, 427, 432-438 copper
ultrasonic testing of petroleum pipes, 441-443 acoustic parameters, 43
ultrasonic testing of storage tanks, 439-440 reflected field amplitude for copper layered steel half space, 49, 50
chemical industry, 428 ultrasonic characterization of grain size of heat treated, 328
chemical spot testing, 12 copper nickel alloys
chewing gum ultrasonic inservice inspection of condensers in power plants, 459
couplant for ultrasonic contact testing, 223 corner welds
Christoffel’s equations, 42 ultrasonic testing in marine industry, 542
civil structures correlation coefficient, 151
ultrasonic testing of wood and structural steel, 476, 477 corrosion. See also corrosion; stress corrosion cracking; thickness testing
cladding angle beam ultrasonic immersion testing of composites, 295
ultrasonic testing in processing plants, 432-433 C-scan mapping in chemical industry, 431
ultrasonic testing with dual-element transducers, 235 detection using nondestructive testing, 2
ultrasonic testing with electromagnetic acoustic transducers, 120-121 material test issues in aerospace applications, 495
clustering and nuclear power plant life, 465
ultrasonic signal processing applications, 168-170 ultrasonic field testing of bridges, 478
coatings ultrasonic inservice inspection in power plants, 458
material test issues in aerospace applications, 495 ultrasonic inservice inspection of aircraft, 512-513
ultrasonic testing assessment, 378-379 ultrasonic inservice testing of offshore structures, 445-446, 451-452
cobalt ultrasonic testing in chemical and petroleum applications, 436
ultrasonic testing of ingots, 401 ultrasonic testing of fossil plant boilers, 466, 467
cobalt alloys ultrasonic testing of fossil plant steam lines and headers, 469
ultrasonic testing of ingots, 401 ultrasonic testing of steel structures, 477
coefficient of autocorrelation and correlation, ultrasonic signal processing, 151 ultrasonic thickness testing in marine industry, 543
coiflet wavelet, 163 couplant path length, 262
cold reheat line, 458 couplants, for ultrasonic transducers
cold shuts contact systems, 221-224
ultrasonic testing of marine industry castings, 542 immersion systems, 262
Columbia Accident Investigation Board, 522-523 coupling
composite laminates operating techniques to ensure good coupling in ultrasonic testing, 223-
discontinuities in, 184-285
focused beam ultrasonic tests, 299 224
pulse echo immersion ultrasonic testing, 273 piezoelectric materials, 64-65, 71
ultrasonic immersion testing, 285 in ultrasonic spectroscopy, 159
ultrasonic testing, 380-390 cracks. See also stress corrosion cracking
composite materials. See also carbon, ceramic, graphite acoustic microscopy, 544
acoustic microscopy, 547-548 aerospace applications, ultrasonic testing in, 494
acoustoultrasonic testing of interlaminar shear strength, 339-340 angle beam contact testing, 217
angle beam ultrasonic immersion testing, 293-295 angle beam immersion testing, 290, 291
increasing use in aircraft, 500 A-scan sensitivity, 179-180
material production inspection in aerospace applications, 499-503 detection using nondestructive testing, 2
pulse echo contact ultrasonic testing, 207-208, 212, 215-216 fossil plant boilers, ultrasonic testing of, 467-468
as replacement for steel and iron, and need for nondestructive testing, 3 highway bridges, ultrasonic testing of, 477
ultrasonic immersion scanning, 284-288 lamb wave applications, 100
ultrasonic immersion testing, 284-288 liquid penetrant indication, 8
ultrasonic inservice inspection of aircraft, 514 marine industry castings, ultrasonic testing of, 542
ultrasonic inservice testing of aircraft, 507 material test issues in aerospace applications, 495
phased array ultrasonic testing applications, 248
straight beam contact pulse echo tests, 206

574 Ultrasonic Testing

structural concrete, ultrasonic testing of, 481, 484, 485 density
ultrasonic delta testing, 233 common materials, 497
ultrasonic immersion testing interpretation of indications from rotor sintered ceramics, 359
ultrasonic characterization, 329
wheels, 280-283
ultrasonic inservice detection of marine, 542 depth detectors
ultrasonic inservice inspection of aircraft, 507, 508-512, 514 amplitude and transit time system, 178
ultrasonic material inspection in aerospace applications, 504 ultrasonic, 25
ultrasonic testing advantages and limitations, 496
wood and structural steel in infrastructure, ultrasonic testing of, 477 depth of field
creep linear phased transducer arrays, 243
acoustoultrasonic damage assessment of nickel alloy space system turbine,
derived units, 30
524-525 detection, of ultrasound, See ultrasound generation and detection
ultrasonic inservice inspection in power plants, 458 deterministic signals, 144-145
ultrasonic inservice inspection of turbines in power plants, 459 Deutsches Institut für Normung (German Institute for Standardization)
ultrasonic testing of fossil plant boilers, 468
ultrasonic testing of fossil plant steam lines and headers, 469 DIN 54123, 17
critical angle, 54 DIN 65455, 17
reflection of ultrasonic waves for incident angles greater than, 55-56 DIN 25435 P1, 17
reflection of ultrasonic waves for incident angles less than, 54-55 standards for ultrasonic testing, 17
critical angle reflection, 54 dielectric constants
cross-correlation, 151-152 piezoelectric materials, 63-64
cross correlation coefficient, 151 diesel generator
C-scanning laser acoustic microscopy, 544, 545-546, 547 infrared thermography of acoustic transfer switches, 11
C-scan ultrasonic equipment, 181, 264-265 digital signals, 146
acoustic microscopes, 192 digital spectrum analyzers
automated techniques for chemical industry, 431 ultrasonic spectroscopy application, 160-161
discontinuity detectability, 181 digital thickness instrumentation, See thickness measurement
internal rotary ultrasonic testing, 429, 430 digitization, 148-149
material production inspection in aerospace applications, 502 dilational longitudinal waves, 39, 43
not directly suitable for structural concrete, 481 diplexers
phased array application, 241 ultrasonic testing application, 82
synthetic aperture focusing, 486 dirac delta function, 157
ultrasonic inservice inspection of aircraft, 514 dirac impulse, 146
for ultrasonic testing of storage tanks, 439 direct pitch catch ultrasonic testing technique, 230
curie point, 66 direct transmission technique, 482
cylinders disbonds
natural waveguides, 101 focused beam ultrasonic tests of aluminum laminates, 299
ultrasonic testing of high pressure gas, 432 material test issues in aerospace applications, 495
visual testing using borescope, 7 nondestructive testing detection, 2
ultrasonic material inspection in aerospace applications, 501
D ultrasonic testing advantages and limitations, 496
discontinuities. See also specific names, such as cracks
damping measurement, 308-309 acoustical holography, 300
data acquisition acoustic microscopy, 544
angle beam contact testing, 217
in ultrasonic signal processing, 147-149 angle beam immersion testing, 289, 290
in ultrasonic testing of rolled aluminum, 415-417 A-scan ultrasonic detectability, 179-180, 264
data structure B-scan ultrasonic detectability, 181, 264
in ultrasonic signal processing, 166-168 C-scan ultrasonic detectability, 181, 264-265
daubechies wavelet, 162-163 C-scan ultrasonic evaluation in chemical industry, 431
dead zone, in ultrasonic testing, 234 immersion ultrasonic testing indication interpretation, 274-283
C-scanning laser acoustic microscopy, 546 laser ultrasonic applications for detection, 112-113
and linear scanning of welds, 93 material test issues in aerospace applications, 495
straight beam contact tests, 204 nondestructive testing detection, 2, 437
ultrasonic testing of aluminum alloys, 410 reliability of detection, 16
decibel (dB), 32 straight beam contact pulse echo tests, 204-214
deck, ultrasonic testing of highway bridge, 476-477 structural concrete, 484-485
deconvolution ultrasonic detection history of use, 26-27
ultrasonic signal processing, 153-154 ultrasonic field testing of bridges, 478
deformation ultrasonic immersion testing interpretation of grain size, 279-280
piezoelectric action, 60 ultrasonic immersion testing of composite materials, 284-285
delamination ultrasonic inservice detection, 9
acoustic microscopy, 544 ultrasonic inservice inspection of aircraft, 514
laser ultrasonic inspection, 112 ultrasonic pulse echo contact testing of butt welds, 225-228
material test issues in aerospace applications, 495 ultrasonic pulse echo immersion test parameters, 272
through-transmission ultrasonic testing, 266 ultrasonic signal distribution contrasted to noise, 533
ultrasonic immersion testing of composite laminates, 285 ultrasonic testing advantages and limitations, 496
ultrasonic inservice inspection of aircraft, 514 ultrasonic testing in aerospace applications, 494
ultrasonic material inspection in aerospace applications, 501, 504 ultrasonic testing in marine industry, 541-543
ultrasonic testing advantages and limitations, 496 ultrasonic testing of advanced structural ceramics, 358, 362-363
ultrasonic testing in processing plants, 432-433 ultrasonic testing of composite laminates, 380-382
ultrasonic testing of advanced materials, 385, 389 ultrasonic testing of diffuse, and microstructure, 324-330
ultrasonic testing of composite laminates, 380 ultrasonic testing of rail axles, 538
ultrasonic testing of structural concrete, 481 ultrasonic testing of rail track, 535-536
delays lines, for ultrasonic testing ultrasonic testing of rail wheels, 540
for contact coupling, 222 ultrasonic testing of rolled aluminum plates, 406
for immersion coupling, 262 ultrasonic testing of structural concrete, 481
delta effect, 233 ultrasonic time-of-flight diffraction tests for sizing, 232
delta indirect pitch catch ultrasonic testing technique, 233-234 discrete attenuators
ultrasonic pulse echo test systems, 183
discrete wavelet transform, 162
disk keyway cracking, 471

Index 575

dispersion employee certification, 16-22
in ultrasonic waveguides, 102-104 EN standards. See European Committee for Standardization
equivalent circuits, piezoelectric elements, 66-67
dispersive materials, 38 equivoluminal waves, 39, 43
displacement, 36 erosion. See also corrosion; thickness testing

piezoelectric actions, 60 ultrasonic inservice inspection in power plants, 458
rayleigh surface waves, 45 ultrasonic inservice inspection of aircraft, 514
units for, 31-32 ultrasonic testing of fossil plant boilers, 466
display, 15. See also A-scan ultrasonic equipment; B-scan ultrasonic ultrasonic testing of fossil plant steam lines and headers, 469
ultrasonic testing of pressure vessels in processing plants, 438
equipment; C-scan ultrasonic equipment ultrasonic thickness testing in marine industry, 543
options, 180 European Committee for Standardization
send/receive instrumentation, 182 EN 583, 19
video, 187 EN 1330-4, 19
distance amplitude calibration blocks EN 1712, 19
for ultrasonic test equipment, 196-197, 198 EN 1713, 19
distance amplitude correction EN 1714, 19
for ultrasonic test equipment, 502 EN 10160, 19
distance measures EN 10228, 19
ultrasonic signal processing applications, 169, 171 EN 10246, 19
distance sensitivity calibration blocks EN 10306, 19
for angle beam contact testing, 217 EN 10307, 19
distortional waves, 43 EN 10308, 19
divided ring phased array, 248 EN 12223, 19
dribbler ultrasonic testing systems, 500 EN 12504, 19
advantages and limitations of, 501 EN 12668, 19
drill casings EN 12680, 19
ultrasonic testing, 441-443 EN 13100-3, 19
dry ply EN 14127, 19
material production inspection in aerospace applications, 504 EN 27963, 19
material test issues in aerospace applications, 495 ENV 583-6, 19
dual transducer ultrasonic testing technique, 179, 421 ENV 14186, 19
described, 232-233, 234-235 PREN 2003-8, 19
for ultrasonic materials characterization, 312-314 ultrasonic testing standards issued by, 19
duel-element transducers, for ultrasonic testing, 234-235 evaluation, 16
dynamic focusing, 422 exfoliation corrosion
dynamic resonance, 308-309, 319-320 ultrasonic inservice inspection of aircraft, 513
expert systems
E ultrasonic signal processing applications, 172
external power amplifiers
earthquake damage ultrasonic testing application, 82, 83-84
ultrasonic field testing of bridges, 478 external receiver preamplifiers
ultrasonic testing application, 82, 83-85
echo ranging, 25 extruders
eddy current testing, 9 ultrasonic testing in processing plants, 433
extrusions
fossil power plant turbines, 470 ultrasonic immersions testing indication formation, 277
edge effect, 278
elastically anisotropic material, 40 F
elastically isotropic material, 40
elastic anisotropy, 324-325 failure
elastic constants, 306 causes of material failure assessed by ultrasonic testing, 307
rising cost of, 4
laser ultrasonic material characterization, 113
piezoelectric materials, 62-63 false alarms
and ultrasonic propagation speed, 320-321 and space scattering diagrams, 168
elastic properties
ultrasonic measurement, 319-323 false call rates, 532
electrical losses false positives, 532
piezoelectric materials, 65 far surface. See back surface
electric charge fasteners. See also bolts
in equivalent circuit of piezoelectric element, 66
electric power applications ultrasonic testing in processing plants, 434
ultrasonic inservice inspection in power plants, 458-460 fast fourier transform, 162
ultrasonic testing, 457 fast wavelet transform, 162
ultrasonic testing in fossil power plants, 466-472 father wavelet, 162
ultrasonic testing in nuclear power plants, 461-465 fatigue
electroacoustics, 25
electromagnetic acoustic transducers (EMATs), 29, 115-117 ultrasonic field testing of bridges, 478
advantages, 115-116 ultrasonic inservice inspection in power plants, 458
high-speed self-aligning probes, 127-128 ultrasonic inservice inspection of turbines in power plants, 459
high temperature tests, 121-122 ultrasonic testing of fossil plant steam lines and headers, 469
modeling, 116-117 ultrasonic testing of space system composite materials, 516-519
probe configurations, 115 fatigue cracking
stress measurements, 128 material test issues in aerospace applications, 495
tests in vacuum, 127 ultrasonic field testing of bridges, 478
tests with moving, 122-127 feature mapping, 166
thickness gaging with, 117-118 and pulse echo immersion test parameters, 271
and transverse horizontal wave propagation, 49 ultrasonic signal processing applications, 172
weld and cladding tests, 118-121 feature vectors, 165-166
electromagnetic position encoding, 210 ferroelectric materials
electromechanical coupling factor, 64, 71, 72, 73 piezoelectric, 60
electronic focusing, 90 ferromagnetic materials
electronic scanning, 92 electromagnetic acoustic transducers for testing, 116
electrostatic transducers, 131 ultrasonic elastic property measurement, 322-323
EMATs. See electromagnetic acoustic transducers

576 Ultrasonic Testing

fiber reinforced epoxy composite laminate G
ultrasonic signal processing using smoothing, 154, 155
gain
fiber reinforced plastic adjustment in calibration, 194
ultrasonic testing of highway bridge, 477 instrument controls, 186, 187

fiber reinforced polymer composite laminate glass epoxy gating
material production inspection in aerospace applications, 499-503 amplitude gating technique, 205
material test issues in aerospace applications, 495 analog gates, 150, 159
angle beam immersion ultrasonic systems, 291
fire protection programs for C-scan ultrasonic systems, 180-181
and nuclear power plant life, 465 in ultrasonic signal processing, 149-150
in ultrasonic spectroscopy, 159
Firestone’s early ultrasonic testing instrument, 28
fisher linear discriminants gels
couplants for ultrasonic contact testing, 223
ultrasonic signal processing applications, 170
flexible resin general purpose ultrasonic testing equipment, 188
generation, of ultrasound, See ultrasound generation and detection
characteristic parameters in filament wound tubes, 288 girders
ultrasonic immersion testing of composites, 288
flexural modes, 100 ultrasonic testing of highway bridge, 476
flexural vibration, 319-320 glass
flooded member detection
ultrasonic testing of offshore structures, 447-449, 453 acoustic parameters, 43
fluid coupled layered half space, 49 glycerin
fluid delay line, for immersion coupling, 262
foam core composites couplant for ultrasonic contact testing, 223
material test issues in aerospace applications, 495 gold
foam core laminates
material production inspection in aerospace applications, 503-504 love mode on fused quartz, 51
focal distance good feature, 164
ultrasonic transducers, 98-99, 297-298 grain boundaries, 324
focused beam ultrasonic immersion techniques, 95-96, 296-299
focused piezoelectric crystal acoustic holography, 300 effect on ultrasonic elastic property measurement, 319
focused transducers, 95-96 grain orientation
focused ultrasonic beam, 97
forging bursts effect on ultrasonic elastic property measurement, 321
ultrasonic immersion testing interpretation of indications from rotor and mechanical properties, 331
grain shape
wheels, 282 effect on ultrasonic elastic property measurement, 319
forgings grain size, 324
and ultrasonic characterization of elastic properties, 327-329
bibliography, 424 and ultrasonic characterization of mechanical properties, 331, 332
material test issues in aerospace applications, 495 grain size distribution, 324, 327
ultrasonic immersion testing indication formation, 277 graphite epoxy composites
ultrasonic material inspection in aerospace applications, 504 acoustoultrasonic testing of interlaminar shear strength, 339-340
ultrasonic testing in marine industry, 541 angle beam ultrasonic immersion testing, 293
ultrasonic testing in processing plants, 434-435 laser ultrasonic testing, 112
ultrasonic testing of aluminum, 406, 417 ultrasonic feature vector studies, 166
fossil fuel power plants ultrasonic immersion testing of delamination, 285
steam generation in, 458 ultrasonic interface transmission and reflection coefficients, 497
ultrasonic testing applications, 466-472 ultrasonic wavelength, 497
fossil plant boilers graphite epoxy sandwich
ultrasonic testing, 466-468 ultrasonic testing of adhesive bonds, 377
fossil plant headers graphite fiber reinforced amorphous thermoplastic polyimide laminates
ultrasonic testing, 468-469 ultrasonic testing in space systems, 518
fossil plant steam lines, 458 graphite fiber reinforced bismaleimide thermoset composite
ultrasonic testing, 469-470 ultrasonic testing in space systems, 518
fracture analysis graphite-to-epoxy honeycomb structures
and ultrasonic materials characterization, 307 ultrasonic testing of adhesive bonds, 372
fracture toughness graphite-to-epoxy laminate
ultrasonic measurement, 333-336 ultrasonic testing, 384-389
frequency grass, 211
downshift from water as ultrasonic testing couplant, 270 grease
filters, 87 couplant for ultrasonic contact testing, 221, 223
limitations of piezoelectrics, 65 green state ceramics
ultrasonic test systems, 15 ultrasonic testing, 358-359
waves, 36, 37 grid spacing, in ultrasonic imaging, 225
frequency constant, 65 griffith model, of strength, 331-332
full-skip test, of butt welds by ultrasonic testing, 226 group velocity, 38
full-V test, of butt welds by ultrasonic testing, 226 anisotropic materials, 40
fused quartz effect on ultrasonic microstructure characterization, 325-326
acoustic parameters, 43 guided ultrasonic waves, 100, 101-106
love mode of gold on, 51 advanced ceramics applications, 365
future usefulness, and nondestructive testing, 2 gums
fuzzy logic couplant for ultrasonic contact testing, 223
ultrasonic signal processing applications, 170
H

half-skip test, of butt welds by ultrasonic testing, 226
half-V test, of butt welds by ultrasonic testing, 226
hall-petch model, of strength, 332
hardness

ultrasonic measurement, 332-333
harmonic plane wave, 36
heat exchangers

ultrasonic inservice inspection in power plants, 459
ultrasonic testing of tubes in processing plants, 437

Index 577

heat resistant glass inductance
acoustic parameters, 43 in equivalent circuit of piezoelectric element, 66
ultrasonic transducers, 69-71
heat treating scale
ultrasonic indications from, 283 industrial applications, See particular industries
industrial production ultrasonic testing systems, 184
hertz (Hz), 32, 36 infrared testing, 11-12
high frequency acoustics, 24 infrastructure applications
high frequency air coupled transducers, 131-132
high frequency piston generator, 24 ultrasonic testing, 475-487
high-speed self-aligning electromagnetic acoustic transducer probes, 127-128 ultrasonic testing of structural concrete, 481-487
high temperature ultrasonic testing of wood and structural steel, 476-480
ingots
ultrasonic testing standoffs, 222 discontinuities in, 400-401
ultrasonic testing with electromagnetic acoustic transducers, 121-122 ultrasonic testing procedures, 401
high temperature bolts ultrasonic tests of steel and wrought alloys, 400
ultrasonic testing of fossil power plant turbine, 471-472 in-house programs
highway bridges for managing ultrasonic testing programs, 14
acoustic emission monitoring of floor beam, 10 initial pulse, 272
ultrasonic field testing, 478-480 inservice testing, 9
ultrasonic testing, 476-477 inservice ultrasonic testing of offshore structures, 444-453
holes ultrasonic inservice inspection in power plants, 458-460
ultrasonic inservice inspection of aircraft, 514 ultrasonic testing in marine industry, 542-543
holography, 12 ultrasonic testing of aircraft, 507-515
honey instrumentation, for ultrasonic testing, 177. See also A-scan ultrasonic
couplant for ultrasonic contact testing, 223
honeycomb structures equipment; B-scan ultrasonic equipment; C-scan ultrasonic equipment
material test issues in aerospace applications, 495 acoustic microscopes, 192
ultrasonic inservice inspection of aircraft, 514 for aluminum testing, 414-415
ultrasonic material inspection in aerospace applications, 503-504 amplitude and transit time systems, 178-180
ultrasonic testing of adhesive bonds, 372 amplitude systems, 178
Hooke’s law, 41 basic send/receive instrumentation, 182-190
hot tears calibration, 194-198
ultrasonic testing of marine industry castings, 542 continuous wave technique, 192-193
hydrogen entrapment equipment classification, 178
ultrasonic tests of steel and wrought alloys, 400 general purpose, 188
hydrostatic pressure testing, 2 instrument control effects, 183
modular, 184, 189-190
I multiple-transducer techniques, 418-419
operation in large testing systems, 193
ice portable, 184, 185-188
acoustic parameters, 43 reference reflectors, 194-195
scanning approaches, 178-181
image analysis, 164 special purpose, 184-185, 191-193
immersion macroscanning, 315 straight beam tests, 202-203
immersion tanks, 267 and transducer characterization, 68-69
immersion ultrasonic testing systems, 262, 299. See also pulse echo immersion types, 184
interface echo, 445
ultrasonic test systems interface triggering
advantages of, 263, 501 in general purpose ultrasonic test equipment, 188, 189
angle beam techniques, 289-295 in portable ultrasonic test equipment, 185
composite materials, 284-288 interlaced scanning, 244
coupling devices, 267-269 interlaminar shear strength
early development of, 29 acoustoultrasonic testing, 339-340
focused beam techniques, 296-299 interleaving, 149
loss of back surface reflection, 275-276 International Institute of Welding (IIW) reference block, 196, 197-198
metals, 401-403 angle beam contact testing application, 217, 218
through-transmission tests, 265 International Organization for Standardization (ISO) , 19, 22
impact damage ISO 2400, 19
aerospace material test issues, 495 ISO 4386-1, 19
characteristic parameters in filament wound tubes, 288 ISO 5577, 19
pulse echo immersion ultrasonic testing, 273 ISO 5948, 19
space shuttle thermal protection, 522-523 ISO 7963, 19
ultrasonic immersion testing of composites, 287 ISO 9303, 19
impedance matching layers, air coupled transducers, 132 ISO 9305, 19
impedance matching networks ISO 9712, 22
and transducer characterization, 69 ISO 9764, 19
ultrasonic testing application, 83 ISO 9765, 19
impulse function, 152 ISO 10124, 19
inclusions ISO 10332, 19
acoustic microscopy, 544 ISO 10375, 19
A-scan sensitivity, 179-180 ISO 10423, 19
material test issues in aerospace applications, 495 ISO 10543, 19
ultrasonic immersion testing interpretation of indications from rotor ISO 11496, 19
ISO 12094, 19
wheels, 281-282 ISO 12710, 19
ultrasonic material inspection in aerospace applications, 501, 504 ISO 12715, 19
ultrasonic testing advantages and limitations, 496 ISO 13663, 19
ultrasonic testing of rolled aluminum plates, 406 ISO 17640, 19
ultrasonic tests of steel and wrought alloys, 400 ISO 18175, 19
incomplete penetration ISO 22825, 19
ultrasonic field testing of bridges, 478 International Space Station
index distance, 414 ultrasonic spectroscopy of flywheel rotors, 521-522
indirect pitch catch ultrasonic testing technique, 230-231 ultrasonic testing applications, 516
indirect transmission technique, 482, 483

578 Ultrasonic Testing

International System of Units (SI), 30-32 lamb waves, 100
interpretation, 16 and angle beam immersion technique, 289
fatigue and thermal damage in space systems composites, 516-519
angle beam ultrasonic immersion techniques, 291-292 leaky, 374-377, 386-389
immersion ultrasonic scanning indications, 274-283 and ultrasonic guided waves, 101
inverse fourier transform, 146
inverse piezoelectric effect, 25 Lamé’s constants, 41
iron. See also steel relation to ultrasonic wave speed and other elastic constants, 319
replacement, and need for nondestructive testing, 3
irrotational longitudinal waves, 39, 43 lamina, 294, 381
ISO. See International Organization for Standardization landing gear
isotropic materials
ultrasonic property characterization of transversely isotropic, 320 ultrasonic inservice testing, 508-509
ultrasonic wave propagation in, 40, 41-45 ultrasonic material characterization, 323
ultrasonic wave reflection at plane boundaries in stress free media, 52 langevin sandwich transducer, 26, 27
laser based ultrasound, 29, 107
J advantages and limitations of, 500-501
applications, 111-114
Japanese Standards Association, 20 optical detection of ultrasound, 109-111
JSA G 0582, 20 optical generation of elastic waves, 107-109
JSA G 0584, 20 for ultrasonic materials characterization, 314
JSA G 0587, 20 waves from ablated surface, 108, 109
JSA G 0801, 20 waves from constrained surface, 108, 109
JSA G 0802, 20 laser ultrasonics, 107
JSA G 0901, 20 layered half spaces, ultrasonic wave propagation in, 47-49
JSA H 0516, 20 guided waves, 101
JSA K 7090, 20 lead
JSA Z 2344, 20 acoustic parameters of pure, 43
JSA Z 2345, 20 lead antimony alloy
JSA Z 2350, 20 acoustic parameters, 43
JSA Z 2351, 20 lead titanate
JSA Z 2352, 20 piezoelectric material, 60
JSA Z 2354, 20 lead zirconate
JSA Z 2355, 20 piezoelectric material, 60
JSA Z 3060, 20 lead zirconate titanate (PZT)
JSA Z 3062, 20 cork and balsa wood for matching to air in ultrasonic transducers, 132
JSA Z 3070, 20 ultrasonic interface transmission and reflection coefficients, 497
JSA Z 3080, 20 in ultrasonic transducers for aerospace applications, 496
JSA Z 3081, 20 leak before failure, 469
JSA Z 3082, 20 leak testing, 9-10
JSA Z 3871, 20 leaky lamb waves, 374-377, 386-389
leaky rayleigh waves, 46-47
K and acoustic microscopy, 299
fluid coupled layered half space, 49
knot, 380 ligament cracking, 468
characteristic parameters in filament wound tubes, 288 linear discriminant functions
ultrasonic immersion testing of composites, 286 ultrasonic signal processing applications, 171
linear discriminants
Korean Standards Association, 20 ultrasonic signal processing applications, 170
KSA B 0521, 20 linear elastic materials, 38
KSA B 0522, 20 linear phased transducer arrays, 229, 238, 418
KSA B 0532, 20 operation, 242-244
KSA B 0533, 20 linear synthetic aperture focusing ultrasonic testing technique, 252
KSA B 0534, 20 liquid penetrant testing, 8
KSA B 0535, 20 laser ultrasonic testing compared for stainless steel, 113
KSA B 0536, 20 liquid surface detector acoustic holography, 300-301
KSA B 0537, 20 longitudinal acoustic impedance
KSA B 0817, 20 typical materials, 43
KSA B 0831, 20 longitudinal modes, 100
KSA B 0896, 20 longitudinal modulus
KSA B 0897, 20 relation to ultrasonic wave speed and other elastic constants, 319
KSA D 0040, 20 ultrasonic measurement, 320
KSA D 0075, 20 longitudinal scanning technique, 414
KSA D 0233, 20 longitudinal vibration, 319-320
KSA D 0250, 20 longitudinal wave modes, 36, 39, 43
KSA D 0252, 20 reflection at plane boundary in stress free media, 52-53
KSA D 0273, 20 loudness, 32
love mode, 51
kronecker delta function, 147 low frequency air coupled transducers, 130-131
low modulus fibers
L characteristic parameters in filament wound tubes, 288
ultrasonic immersion testing of composites, 288
laboratory ultrasonic testing systems, 184-185 low pass filtering, 187
lack of fusion
M
material test issues in aerospace applications, 495
pulse echo contact imaging of butt welds, 226 machined parts
ultrasonic field testing of bridges, 478 material production inspection in aerospace applications, 504
lack of rovings material test issues in aerospace applications, 495
characteristic parameters in filament wound tubes, 288
ultrasonic immersion testing of composites, 286, 287 machines
increased demand on, and nondestructive testing, 3

magnesia stabilized zirconia transfer curve, 361

Index 579

magnesium minimum distance classifier
acoustic parameters, 43 ultrasonic signal processing applications, 171
ultrasonic wavelength, 497
modular industrial ultrasonic testing instruments, 184
magnesium alloys modular ultrasonic testing instruments, 189-190
as replacement for steel and iron, and need for nondestructive testing, 3 moiré imaging, 12
moisture ingress
magnetic particle testing, 8
fossil power plant turbines, 470 material test issues in aerospace applications, 495
petroleum pipes, 441 molybdenum

magnetization acoustic parameters, 43
effect on ultrasonic elastic property measurement, 322 molybdenum alloy

magnetoelasticity, 323 acoustic parameters of wrought, 43
magnetostrictive effect, 25 monolithic linear phased transducer arrays, 242
main bang signal, 272 morphology, 306, 324
manipulator, ultrasonic immersion system, 413-414 mosaic phased array ultrasonic testing, 238
manual scanning, 204 mother wavelet, 162, 163
Manufacturers Standardization Society of the Vale and Fittings Industry multibeam satellite pulse observation technique, 235
multiclass problems
MSS SP-94, 17
standards for ultrasonic testing, 17 ultrasonic signal processing applications, 171-172
marine industry applications, 541-543 multidiscriminant analysis
ultrasonic detection of submarines, 25, 26, 28
martensitic stainless steel ultrasonic signal processing applications, 171-172
acoustic parameters, 43 multiparametric scanning, 317
matching layers, air coupled transducers, 130 multiple discriminant analysis
impedance materials layers, 132
materials for, 132 ultrasonic signal processing applications, 172
material identification, 2, 12 multiple-transducer ultrasonic testing techniques
material property characterization, 305
acoustoultrasonic testing for mechanical properties, 338-342 metals testing, 418-419
laser ultrasonic applications, 113-114 pulse echo contact ultrasonic test systems, 229-237
microstructure and diffuse discontinuities, 324-330 multiplexers
ultrasonic testing applications, 306-318 ultrasonic testing application, 82, 229
ultrasonic testing for elastic properties, 319-323 multipliers, for SI units, 30-31
ultrasonic testing for mechanical properties, 331-337 multizone ultrasonic technique, 419, 420
materials characterization, 2, 307
ultrasonic testing application, 308-318 N
maximum entropy spectrum analysis
ultrasonic spectroscopy application, 162 narrow band instrumentation, 183
maximum likelihood spectrum analysis National Aeronautics and Space Administration (NASA)
ultrasonic spectroscopy application, 162
mechanical impedance, 61 damage tolerance approach, 530, 531
air, 129 ultrasonic testing of space systems, 516
mechanical losses National Electrical Safety Code, 22
piezoelectric materials, 66 National Electric Code, 22
mechanical position encoding, 209 natural waveguides, 101
mechanical properties naval brass
acoustoultrasonic characterization, 338-342 acoustic parameters of, 43
sintered ceramics, 359 network analyzers
ultrasonic characterization, 306, 331-337 ultrasonic spectroscopy application, 159-160
mechanical scanning, 209-210 neural networks
medical applications ultrasonic signal processing applications, 172-173
B-scan ultrasonic testing applicable to, 264 newton per square meter, 31
ultrasonic moving transducer tests, 252 nickel
membranes acoustic parameters, 43
ultrasonic contact coupling applications, 222 angle beam immersion ultrasonic testing of tubes, 292
metal composite laminates ultrasonic characterization of grain size of heat treated, 328
angle beam ultrasonic immersion testing, 295 ultrasonic wavelength, 497
metals applications, 399 nickel alloys
ultrasonic multiple-transducer techniques, 418-422 ultrasonic testing of ingots, 401
ultrasonic testing of primary aluminum, 406-417 nickel alloy UNS N07520
ultrasonic testing of steel and wrought alloys, 400-405 acoustoultrasonic creep damage assessment of space system turbine, 524-
metals fabrication
ultrasonic testing at high temperature using electromagnetic acoustic 525
nickel chromium alloy
transducers, 122
methods, 2 acoustic parameters of wrought, 43
methyl methacrylate no entry areas, 22
nondestructive material characterization, 2
wedges for angle beam transducers, 75, 76, 77 nondestructive testing
microelectronic packaging applications
applications, 4
acoustic microscopes, 192 defined, 2
microstructure, 2, 306 methods classification, 4-7
methods overview, 7-12
effect of mechanical and thermal processes, 212 objectives, 5
and ultrasonic attenuation, 326-327 purposes, 2-4
ultrasonic characterization, 324-330 reliability, 530-534
and ultrasonic speed, 325-326 test object, 5-7
whisker reinforced ceramics, 362 value of, 7
military specifications, 16 nonmetallic inclusions
MIL-A-8344, 530-531 ultrasonic tests of steel and wrought alloys, 400
MIL-HDBK-1823, 531, 534 nonperiodic waves, 38
MIL-HDBK-5 B, 531 normalization
MIL-STD-1530, 530-531 ultrasonic signal processing, 154
MIL-W-22759/34, 520 nozzles
ultrasonic testing in nuclear power plants, 461, 464

580 Ultrasonic Testing

nuclear power plant applications pigs, 441
couplants for ultrasonic contact testing, 223 pin assemblies, bridge
life extension, 464-465
steam generation in, 458 ultrasonic field testing, 479-480
ultrasonic testing applications, 459, 461-465 pipe (ingot defect)

nuclear reactor pressure vessels ultrasonic tests of steel and wrought alloys, 400
ultrasonic testing, 461-462 Pipe Fabrication Institute

nyquist frequency, 148 PFI ES-20, 17
PFI ES-30, 17
O standards for ultrasonic testing, 17
pipelines
Occupational Safety and Health Standards, 23 guided wave ultrasonic inspection, 105
Occupational Safety and Health Standards for the Construction Industry, 23 tests with moving electromagnetic acoustic transducers, 122-123
oil, See chemical and petroleum applications ultrasonic scanning of welds, 93, 94
oils ultrasonic testing of petroleum, 441-443
pipe mills
acoustic parameters of transformer, 43 phased array ultrasonic testing of, 249
couplant for ultrasonic contact testing, 221, 223 pipes and piping
one-dimensional transducer array, 418 angle beam ultrasonic immersion testing, 293
operation of deconvolution, 153 dispersion in ultrasonic waveguides in pipes, 102-103
optical heterodyning, 109 internal rotary ultrasonic testing of chemical industry, 429-430
optical methods, 12 lamb wave applications, 100
optical ultrasound probes, 111 semiautomated contact phased array testing, 241
oxidation ultrasonic bonding tests in marine industry, 542
ultrasonic inservice inspection in power plants, 458 ultrasonic inservice inspection of condensers in power plants, 459
ultrasonic testing of fossil plant boilers, 468 ultrasonic material characterization of stainless steel, 323
ultrasonic scanning of welds, 90, 92-94
P ultrasonic testing in immersion tanks, 267
ultrasonic testing in marine industry, 541
paintbrush transducers ultrasonic testing in processing plants, 432, 433-434, 436
for ultrasonic testing of aluminum alloys, 411-413 ultrasonic testing of metal, 404-405
ultrasonic testing of nuclear reactor, 462-464
parzen window approach, 166-167 ultrasonic thickness testers, early devices, 29
pascal (Pa), 31 ultrasonic water level determination in marine industry, 543
pattern recognition piston cylinder lugs
ultrasonic inservice testing, 509
ultrasonic signal processing applications, 164-173 pitch catch ultrasonic testing technique, 229
peak detector angle beam contact testing, 219
described, 230-231
ultrasonic testing application, 87, 88-89 send/receive instrumentation, 188
pencil shape focus transducers, 99, 298 two-transducer and massive setups, 420-421
period, 36 for ultrasonic materials characterization, 313-314
periodic signals, 145 planar phased transducer arrays, 229, 238
periodic waves, 38 operation, 244-245
petrochemical plants, 428 plane body waves
petroleum storage tanks propagation in isotropic materials, 41-43
petroleum plane waves, 39
plano concave lenses, 97, 297
industry, 428 plastics
pipelines, ultrasonic testing, 441 wedges for ultrasonic transducers, 74-77
pipes, ultrasonic testing, 441-443 plate followers, 404
pressure vessels, ultrasonic testing in processing plants, 437-438 plate glass
storage tanks, ultrasonic testing, 439 acoustic parameters, 43
petroleum jelly plates
couplant for ultrasonic contact testing, 221, 223 lamb wave propagation in, 100
phase angle, 36 natural waveguides, 101
phased array ultrasonic testing systems, 90-94, 229, 238-249 ultrasonic immersion testing, 263
applications, 248-249 ultrasonic immersion testing indication formation, 276, 277
automated contact, 242 ultrasonic material characterization of stainless steel, 323
chemical industry applications, 431 ultrasonic testing in immersion tanks, 267
combined scans, 92-93 ultrasonic testing in marine industry, 541
manual contact, 240-241 ultrasonic testing in processing plants, 432-433
material production inspection in aerospace applications, 504 ultrasonic testing of metal, 404
multiple-transducer systems, 421-422 ultrasonic testing of rolled aluminum, 406, 413-414
scan types, 92-94 ultrasonic testing of wood and structural steel, 476
semiautomated contact, 241-242 ultrasonic thickness testers, early devices, 29
for testing seamless tubes with moving electromagnetic acoustic ply gap
characteristic parameters in filament wound tubes, 288
transducers, 124-125 ultrasonic immersion testing of composite materials, 284, 286
phase velocity, 37 ultrasonic straight beam testing, 206
ultrasonic testing of advanced materials, 385, 389
effect on ultrasonic microstructure characterization, 325-326 pohlman image cell, 27, 28
piezoelectric elements, 62-66 poling, in piezoelectric materials, 60-61, 65
polymethyl methacrylate
electrode thickness, 74 wedges for angle beam transducers, 75, 76, 77
equivalent circuits, 66-67 polynomial discriminant analysis
in low frequency air coupled transducers, 130 ultrasonic signal processing applications, 172
and transducer performance, 71-74 polystyrene
piezoelectricity, 25, 60-67 wedges for angle beam transducers, 75-77
actions, 60-61 polyvinyllidene fluoride (PVDF)
ceramics, 62, 64 piezoelectric material, 60
constants, 63-65 polyvinyllidene fluoride transducers, 60
effect, 25-26, 60-67
piezoelectric materials, 60-61 Index 581
early development for ultrasonic testing, 26-27
mechanical and acoustical impedance considerations, 61
properties, 62-66
resonant and nonresonant devices, 61-62
piezoelectric resonators, 26

porosity pulsers
angle beam ultrasonic immersion testing of composites, 295 operation, 180-184
A-scan sensitivity, 180 options, 180
detection using nondestructive testing, 2 and transducer characterization, 69
effect on ultrasonic microstructure characterization, 325
and elastic constants, 320-321 pumps
material test issues in aerospace applications, 495 ultrasonic inservice inspection of condensers in power plants, 459
pulse echo contact imaging of butt welds, 227 ultrasonic testing in processing plants, 432
ultrasonic characterization, 329
ultrasonic material inspection in aerospace applications, 501 Q
ultrasonic testing advantages and limitations, 496
ultrasonic testing of composite laminates, 380 qualification, 16-22
ultrasonic testing of marine industry castings, 542 quantization, 148
ultrasonic testing of rolled aluminum plates, 406, 415-416 quartz

porous solids, 319 acoustic parameters, 43
portable ultrasonic testing instruments, 184, 185-188 early ultrasonic transducer tests, 26
portable ultrasonic wave speed testing units, 482 piezoelectric material, 60
portland cement quasifocus point, paintbrush transducers, 412
quasilongitudinal wave modes, 40
ultrasonic testing of structural, 481 quasi transverse wave modes, 40
power boilers
R
ultrasonic inservice inspection in power plants, 458
power cepstrum radar, 2
radian, 32
ultrasonic spectroscopy application, 162 radio astronomy, 2
precipitation radiofrequency amplifiers

ultrasonic characterization, 329 ultrasonic testing application, 87
prefixes, for SI units, 31 radiographic testing, 9-10
pressure coupling, for ultrasonic contact testing, 223
pressure units, 31-32 inservice testing of aircraft, 507
pressure vessels railroad axles

phased array ultrasonic testing applications, 248-249 ultrasonic testing, 538-540
ultrasonic scanning of welds, 93 railroad industry applications, 535
ultrasonic testing in processing plants, 432, 436-438
ultrasonic testing of nuclear reactor, 461-462 ultrasonic testing of axles, 538-540
pressure wave, 36, 52 ultrasonic testing of rail track, 535-538
pressurized water nuclear reactors ultrasonic testing of wheels, 540
ultrasonic testing, 461 ultrasonic testing with moving electromagnetic acoustic
ultrasonic testing of piping systems, 462-463
probability density function analysis transducers, 125-127
ultrasonic signal processing applications, 166-168 railroad wheels
probability of detection, 530-532
probe, 15 testing with moving electromagnetic acoustic transducers, 126-127
processing plants ultrasonic material characterization, 323
ultrasonic testing, 432-438 rail track
proof testing, 2 testing with moving electromagnetic acoustic transducers, 125-126
ultrasonic testing of joints, 505 ultrasonic material characterization, 323
ultrasonic testing of structures, 309 ultrasonic testing, 535-538
propylene glycol ultrasonic thickness testers, early devices, 29
couplant for ultrasonic contact testing, 223 random signals, 144-145
proveup inspections range
ultrasonic testing of petroleum pipes, 441 adjustment in calibration, 194
pulse, 182 range estimating
pulse amplitude, 187 angle beam contact testing, 218
pulse echo contact ultrasonic test systems, 201, 299 Rayleigh (Lord Rayleigh, John William Strutt), 24
angle beam contact testing, 217-220 rayleigh angle, 46
butt weld imaging, 225-228 rayleigh disk, 24
coupling media for, 221-224 rayleigh (surface) waves, 24, 39-40, 101, 220
moving transducers, 250-252 first uses in testing, 29
multiple-transducer techniques, 229-237 leaky, 46-47, 49, 299
phased arrays, 238-249 propagation in isotropic materials, 43-45
straight beam pulse echo tests, 202-216 rear surface. See back surface
test frequency selection, 212-214 receiver saturation avoidance, 188
pulse echo immersion ultrasonic test systems, 299 recertification, 21
amplitude of extraneous reflections, 272 recrystallization
back surface reflection amplitude, 271-272 ultrasonic characterization, 329
frequency domain analysis, 273 rectangular gate function, 149
summary of techniques, 299 reference blocks, ultrasonic. See reference standards
test parameters, 271-273 reference line, 403
time of flight, 272-273 reference signal, 153
pulse echo time-of-flight (TOF) scanning, 272-273, 501 reference standards, ultrasonic. See also calibration blocks
chemical industry applications, 431 aerospace, 499
pulse echo ultrasonic test systems, 99, 262 bonding, 515
adhesive bond testing, 371-373 calibration blocks for ultrasonic testing systems, 195-198
calibration, 194-198 ingot ultrasonic testing, 401
early development of, 29 for interpretation of immersion ultrasonic test indications, 274-275
for materials characterization, 309-312 petroleum pipes, 442
scanning approaches, 178-188 reflectors for calibrating ultrasonic testing systems, 194-195
send/receive instrumentation, 182-190 refineries, 428
special purpose equipment, 191-193 reflection
pulse generator, 69 of ultrasonic waves at plane boundary in stress free media, 52-56
pulse repetition frequency, 187 reflection, of ultrasonic waves, See ultrasonic wave reflection
reflection amplitude, ultrasonic waves, 497
582 Ultrasonic Testing reflection coefficients, ultrasonic waves, 53, 496
common materials, 497

reflection loss, 487 scholte wave, 51
reflection test technique search unit, 15
sectorial scanning, 90, 92
for ultrasonic testing, 179 segregation
reflection tomography, 250
reflective ultrasonic tomography, 250 ultrasonic immersion testing interpretation of indications from rotor
ReflectoscopeTM, 28 wheels, 281-282
refraction, of waves, 38
reinforced concrete ultrasonic testing of steel and wrought alloys, 400
semidirect transmission technique, 482, 483
ultrasonic field testing of bridges, 478 sensitive flame, as detection device, 24
ultrasonic testing of highway bridge, 476 service companies
ultrasonic testing of structural, 481
rejection criteria, See acceptance/rejection criteria for managing ultrasonic testing programs, 14
relative dielectric constant sezawa wave, 48
piezoelectric materials, 64 shear modulus
reliability, 530-533
common mistakes in estimation, 533-534 relation to ultrasonic wave speed and other elastic constants, 319
of discontinuity detection, 16 ultrasonic measurement, 319, 320
residual stresses shearography, 12
material test issues in aerospace applications, 495 bonded joints, 505
ultrasonic testing of rail track, 538 shear waves. See transverse waves
ultrasonic testing of rail wheels, 540 sheets
resins focused beam ultrasonic tests of aluminum laminates, 299
couplant for ultrasonic contact testing, 223 ultrasonic material characterization of stainless steel, 323
resin starved layer ultrasonic testing of aluminum, 406
characteristic parameters in filament wound tubes, 288 shipbuilding
ultrasonic immersion testing of composites, 287 ultrasonic testing applications, 541, 542
resistance ships
in equivalent circuit of piezoelectric element, 66 ultrasonic thickness testing for corrosion, 543
ultrasonic transducers, 69-71 short time fourier transform
resonance mode testing ultrasonic spectroscopy application, 162
adhesive bonds, 370 shrinkage
bonded joints, 505 material test issues in aerospace applications, 495
wood structures, 478 ultrasonic testing of marine industry castings, 542
resonant devices, 61-62 side drilled holes, use in calibration blocks, 195, 198
resonant and nonresonant devices, 61-62 signal acquisition
retaining rings in ultrasonic signal processing, 144-145
ultrasonic testing of fossil power plant turbine, 471-472 signal classification
rheometry, 2 ultrasonic signal processing, 144-146
ringing technique, in ultrasonic testing, 224, 374 signal filtering
rochelle salt instrumentation, 187
piezoelectric material, 60 in ultrasonic signal processing, 152-153
rods signal gates. See also gating
natural waveguides, 101 controls, 187, 188
ultrasonic testing in immersion tanks, 267 options, 180
ultrasonic testing of aluminum, 406 ultrasonic testing application, 88
rogue discontinuity, 531 signal processing
roof angle, of dual-element ultrasonic transducers, 234 for ultrasonic testing systems (See ultrasonic signal processing)
roped off areas, 22 signals, 144-145
signal-to-noise ratio, 144
S and electronic focusing, 90
signature analysis
SAE International ultrasonic signal processing applications, 164-175
SAE AMS 2154, 17 silicon
SAE AMS 2628, 17 velocity dispersion of surface wave on zinc oxide substrate, 48
SAE AMS 2632A, 17 silicon carbide
SAE AMS 2630B, 17 ultrasonic attenuation in, 317, 318, 329-330
SAE AMS 2631B, 17 silicon carbide fiber reinforced silicon carbide
SAE AMS 2633B, 17 ultrasonic testing, 365, 366
SAE AMS 2634B, 17 silicon carbon whisker reinforced alumina
SAE AS 7114/3, 17 transfer curve, 362
SAE J 428, 17 whisker clumps, 365
standards for ultrasonic testing, 17 silicon nitride
ultrasonic testing of coatings, 378
safety, 22-23 ultrasonic testing of reaction bonded, 363
increased public demand for, and nondestructive testing, 4 ultrasonic testing threshold presentation of discontinuities, 365
silver nickel alloy
safety factor, 3-4 acoustic parameters, 43
sample-and-hold circuits simple interferometric detection
of ultrasound, 109-110
ultrasonic testing application, 89 simply leaky surface acoustic waves, 389
sampling, 2 sine wave, 36-39
singing condensers, 25
and data acquisition, 147-148 single transducer technique
sandwich transducers, 26, 27 for ultrasonic testing, 179
scanning, ultrasonic, See ultrasonic scanning sintered ceramics
scanning acoustic microscopy (SAM), 99, 298-299, 544, 546-547 ultrasonic testing, 359-365
scanning head, for ultrasonic scanning, 413-414 ultrasonic testing of surface properties, 367-368
scanning index, in ultrasonic scanning, 403 SI system, 30-32
scanning laser acoustic microscopy (SLAM), 544, 545 slag inclusion
scanning speed, in ultrasonic scanning, 403, 413-414 material test issues in aerospace applications, 495
scattered waves, 38 ultrasonic field testing of bridges, 478
scattering, of waves, 38 ultrasonic testing of marine industry castings, 542
slotting, 242
ultrasonic beams, 211-212
scattering centers, 327 Index 583
schoch displacement, 49

smallest discontinuity ever found, 534 replacement, and need for nondestructive testing, 3
smallest discontinuity that can be found, 534 sound propagation at high temperature, 122
smart pigs, 441 transverse ultrasonic wave attenuation for interface with water, 47
smoothing ultrasonic field testing of bridges, 478
ultrasonic hardness measurement, 333
ultrasonic signal processing, 154-155 ultrasonic inservice inspection of boiler tubes in power plants, 458
Snell’s law, 52 ultrasonic interface transmission and reflection coefficients, 497
Society of Automotive Engineers. see SAE International ultrasonic standard test block material, 403
sokolov image tube, 27 ultrasonic testing, 400-405
sonar, 2 ultrasonic testing high temperature considerations, 121
ultrasonic testing in infrastructure applications, 476-480
development of, 25, 28 ultrasonic testing of adhesive bonds to rubber, 377
sonic analysis, 308 ultrasonic testing of ingots, 401
sonic position encoding, 209-210 ultrasonic testing of seamless tubing with electromagnetic acoustic
SonigageTM, 29
SonizonTM, 29 transducers, 118
sound waves ultrasonic testing of structural reinforced concrete, 481, 483-484, 486
ultrasonic tests with closely positioned transducers, 236
propagation in air, 129 ultrasonic toughness measurement, 334-335
space scattering diagrams ultrasonic wavelength of mild, 497
ultrasonic wavelength of nickel chromium, 497
ultrasonic signal processing applications, 168 ultrasonic wave speed correlates with age hardening, 331
space systems steel, chromium molybdenum
ultrasonic inservice inspection of boiler tubes in power plants, 458-459
ultrasonic testing, 516-525 ultrasonic testing of fossil plant boiler tubing, 466
spalling ultrasonic testing of fossil plant steam lines and headers, 469
steel alloy UNS G43400
ultrasonic testing of structural concrete, 481 ultrasonic immersion testing interpretation of grain size
spark testing, 12
special applications, 530 discontinuities, 279-280
special process, 16 steel jacketed platforms
special purpose ultrasonic testing systems
inservice ultrasonic testing of offshore structures, 444-453
instrumentation, 191-193 steel mills
laboratory testing systems, 184-185
specificity tests with moving electromagnetic acoustic transducers, 123-124
and space scattering diagrams, 168 steel structures
spectral analysis
ultrasonic signal processing applications, 173 inservice ultrasonic testing of offshore structures, 444-453
spectroscopy, 12 ultrasonic field testing of bridges, 478-480
spectrum analyzers ultrasonic testing, 477
ultrasonic spectroscopy application, 159-161 step pulsers, 78, 81
speed of sound, 24 stonely waves, 101
spherical waves, 39 stone masonry
spike pulsers, 78-79, 81 ultrasonic field testing of bridges, 478
square gate function, 149, 150 ultrasonic testing of highway bridge, 476
square wave pulsers, 78, 79-81 storage tanks
squint angle, of dual-element ultrasonic transducers, 234 ultrasonic testing in chemical and petroleum applications, 439-440
stainless steel straight beam contact pulse echo tests, 202-216
acoustic parameters, 43 transducer shoes for, 221
laser ultrasonic testing for stress corrosion cracking, 113 strain
pulse echo contact imaging of butt welds, 227 piezoelectric materials, 62-63
ultrasonic inservice inspection of boiler tubes in power plants, 458 strain gaging, 12
ultrasonic material characterization, 323 stress
ultrasonic signature analysis studies, 164 piezoelectric materials, 62-63
ultrasonic standard test block material, 403 piezoelectric materials under high stress, 66
ultrasonic testing of ingots, 401 stress corrosion cracking
ultrasonic testing of nuclear reactor piping, 462-464 laser ultrasonic testing, 113
ultrasonic testing of welds with electromagnetic acoustic transducers, 118- pulse echo contact imaging of butt welds, 227-228
ultrasonic inservice inspection of turbines in power plants, 459
121 ultrasonic inservice testing of aircraft, 511, 512
ultrasonic wavelength, 497 ultrasonic testing of nuclear reactor welds, 463
standards, 16 stress measurements
for metals, bibliography, 424 ultrasonic field testing of bridges, 478
tests of aircraft, 507-508 using electromagnetic acoustic transducers, 128
ultrasonic testing, 17, 18, 19, 20 structural ceramics
for ultrasonic testing of storage tanks, 439-440 ultrasonic testing of advanced, 358-368
standards, reference (ultrasonic calibration blocks). See reference standards structural concrete
Standards Australia International ultrasonic testing, 481-487
SAI AS 1065, 20 structural materials
SAI AS 1710, 20 and ultrasonic materials characterization, 307
SAI AS 2083, 20 structural steel
SAI AS 2207, 20 ultrasonic testing in infrastructure applications, 476-480
SAI AS 2452.3, 20 Structural Welding Code, 477
SAI AS 2824, 20 submarines
SAI AS/NZS 2574, 20 ultrasonic detection, 25, 26, 28
ultrasonic standards published by, 20 substructure, ultrasonic testing of highway bridge, 476-477
standard water velocity, 270 superstructure, ultrasonic testing of highway bridge, 476-477
standoffs, for ultrasonic contact testing, 222 surface transmission technique, 482
steam generation, 458 surface waves, See rayleigh waves
steam lines, 458-459 surface wave ultrasonic test technique, 179
steel. See also austenitic steel; carbon steel; stainless steel aluminum, 417
acoustic parameters, 43 angle beam contact testing, 179
acoustoultrasonic testing of adhesively bonded, 340 suspension bridge
angle beam contact surface wave testing, 220 ultrasonic testing, 476
dispersion in ultrasonic waveguides in pipes, 104
immersion ultrasonic testing indication formation in bar, 276
laser ultrasonic monitoring of annealing, 113
reflected field amplitude for copper layered steel half space, 49, 50

584 Ultrasonic Testing

sweep titanium
adjustment in calibration, 194 acoustic parameters, 43
instrument controls, 183, 186 ultrasonic inservice inspection of condensers in power plants, 459
options, 180 ultrasonic interface transmission and reflection coefficients, 497
ultrasonic material production inspection of billets in aerospace
sweep generator applications, 504
ultrasonic pulse echo test systems, 182 ultrasonic mechanical property characterization, 331
ultrasonic scanning of aerospace castings, 92
symlet wavelet, 163 ultrasonic testing of adhesive bonds on, 376
symmetric lamb waves, 100 ultrasonic wavelength, 497
synchronizers, 180
synthetic aperture focusing, ultrasonic testing titanium alloys
ultrasonic characterization of grain size, 328
bibliography, 258 ultrasonic toughness measurement, 334-335
described, 250-252
technique, 112-113, 229, 250-252, 485-486 titanium diboride
system amplifier ultrasonic testing of rolled aluminum inclusion, 406, 407
ultrasonic spectroscopy application, 159
tomography. See ultrasonic tomography
T tone burst pulsers, 78, 81
torque measurement technique, 434
tailored welds torsional vibration, 320
phased array ultrasonic testing, 249 toughness

tandem transducer ultrasonic testing, 232-233 ultrasonic measurement, 333-336
tanks tourmaline

ultrasonic water level determination in marine industry, 543 piezoelectric material, 60
tap testing, 12 track, railroad, See rail track
trains, See railroad industry applications
adhesive bond testing, 369-370 train wheels, See railroad wheels
bonded joints, 505 tramp elements, 400
techniques, 2 transducer array, 418
telephone, 25 transducer characterization station, 68-69
temperature transducer far field, 211
and elastic constants, 321 transducer near field, 210-211
tensile strength transducers, 15. See also air coupled transducers; electromagnetic acoustic
ultrasonic measurement, 331-333
test blocks, ultrasonic. See reference standards transducers
test object, 2 alignment in through-transmission technique, 265-266
nondestructive testing methods classified by, 5-7 configurations for multiple-transducer systems, 229
tetragonal zirconia polycrystalline (TZP) effects of angle beam wedge, 74-77
ultrasonic testing, 364 excitation, 78-87
texture focal distance, 98-99
effect on ultrasonic elastic property measurement, 319, 321, 322-323 focused, 95-96, 296-299
and stress, 322-323 generation and reception of ultrasound, 78-89
texturing, 324 history of development, 25-29
Theory of Sound (Rayleigh), 25 instrumentation and transducer characterization, 68-69
thermal coatings multiple-transducer ultrasonic techniques for metals, 418-422
material test issues in aerospace applications, 495 pencil shape focus, 99
thermal damage performance, 69-77
material test issues in aerospace applications, 495 sandwich, 26, 27
ultrasonic testing of fossil plant boilers, 466 shoes for contact testing, 221-222
ultrasonic testing of space system composite materials, 516-519 straight beam contact pulse echo tests, 202-203
thermal testing, 11-12 tests with closely positioned, 235-237
thickness gages, ultrasonic, See thickness measurement; ultrasonic thickness for ultrasonic testing of aluminum alloys, 411-413
ultrasonic thickness gages, 191-192
gages underwater for ultrasonic testing of offshore structures, 449
thickness measurement. See also corrosion; erosion; ultrasonic thickness gages transformer oil
acoustic parameters, 43
with electromagnetic acoustic transducers, 117-118 transformers
instrumentation, 184-185 ultrasonic testing application, 83
laser ultrasonic, 111-112 transient signals, 145-146
ultrasonic applications in marine industry, 542, 543 transmission amplitude, ultrasonic waves, 497
ultrasonic detection of wall thinning in chemical and petroleum transmission coefficient, ultrasonic waves, 496
transmit/receive switches
applications, 435-436 timing and synchronization, 186-187
ultrasonic inservice testing of offshore structures, 445 ultrasonic testing application, 82
ultrasonic testing advantages and limitations, 496 transportation applications
ultrasonic testing of steel structures, 477 lamb wave applications, 100
through arch truss bridge transverse horizontal waves
ultrasonic testing, 476 reflection at plane boundary in stress free media, 53-54
through-transmission ultrasonic testing technique, 99, 179, 229, 262, 299 ultrasonic wave propagation, 49-51
adhesive bonds, 371-373 transverse scanning technique, 414
described, 230 transverse vertical waves
early experiments with, 26 reflection at plane boundary in stress free media, 54
send/receive instrumentation, 188 transverse waves, 36, 39, 43
transducer alignment, 265-266 travel time mode conversion, 236
for ultrasonic materials characterization, 312-313 Treatise on Electricity (Maxwell), 25
ultrasonic testing of reinforced concrete, 481 tubes and tubing
timber angle beam contact testing, 218
ultrasonic testing of highway bridge, 476 angle beam immersion testing, 289-290
time corrected gain, 502 angle beam immersion ultrasonic testing, 292
time correction gain, 414 internal rotary ultrasonic testing of chemical industry, 429-430
time delay interferometric detection, 110 laser ultrasonic thickness gaging in austenitic seamless tubes, 111
time-of-flight diffraction ultrasonic tests, 231-232 phased array testing of seamless with electromagnetic acoustic
timer
ultrasonic pulse echo test systems, 182 transducers, 124-125
timing section, of pulse echo system, 186

Index 585

tests with moving electromagnetic acoustic transducers, 123 ultrasonic spectroscopy, 146, 153, 156-164
ultrasonic immersion scanning of composite, 285-288 adhesive bonds, 373-374
ultrasonic immersion testing, 263 bonded joints, 505
ultrasonic immersion testing of composite, 285-288 composite laminates, 383
ultrasonic testing in processing plants, 433-434, 437 composite Space Station flywheel rotors, 521-522
ultrasonic testing of fossil plant boilers, 466-468 for ultrasonic materials characterization, 314-315
ultrasonic testing of fossil power plant, 466-472
ultrasonic testing of metal, 404-405 ultrasonic testing, 9. See also cracks; discontinuities; transducers; particular
ultrasonic testing of seamless steel with electromagnetic acoustic techniques

transducers, 118 advanced materials, 357-390
tungsten advantages and limitations, 13, 496
aerospace applications, 493-525
acoustic parameters, 43 certification, 16-22
tungsten carbide chemical and petroleum applications, 427-453
coupling techniques, 262
ultrasonic mechanical property characterization, 331 early techniques, 26-27
ultrasonic toughness measurement of cobalt cemented, 334 electric power applications, 457-472
turbines history, 24-29
annular phased array ultrasonic testing of turbine disks, 47 infrastructure applications, 475-487
fossil power plants, ultrasonic testing in, 470-472 introduction, 262-263
pitch catch ultrasonic test of turbine disks, 230 limitations, 13, 496
processing plants, ultrasonic testing in, 432 management, 13-23
sectorial ultrasonic scanning of turbine rotors, 92 marine industry, 541-543
T welds material property characterization, 305-342
ultrasonic testing in marine industry, 542 measurement units for, 30t, 30-32, 31t
two-space plot, 168 metals applications, 399-422
two-space scatter diagram, 168 methods and techniques, 2, 264-266
modern methods, 27-29
U personnel qualification and certification, 16-22
qualification, 16-22
ultrasonic backscattering, 293-295 railroad industry, 535-540
in advanced structural ceramics, 362-363 reliability, 530-534
for materials characterization, 312 representative setup, 7
safety, 22-23
ultrasonic image tubes, 27 selection, 13
ultrasonic imaging special applications, 529-548
standards, 15-16
butt weld pulse echo contact testing, 225-226 techniques, 264-266
for materials characterization, 315-318 test procedures, 14-15
structural concrete, 485-487 test specifications, 15-16
weld scanning, 93 transducer configuration summary, 229
ultrasonic interferometer, 26 transduction mechanism, 25
ultrasonic lenses, 96-97, 296-298 ultrasonic thickness gages, 191-192
ultrasonic metrology, 111 early development, 29
ultrasonic phased array testing systems, See phased array ultrasonic testing ultrasonic tomography, 229
bibliography, 259
systems described, 250
ultrasonic pulses, 144-146 of structural concrete, 485
ultrasonic pulse velocity technique, 481 ultrasonic transmitter, 157-158
ultrasonics, 24 ultrasonic waveforms, 78
ultrasonic wave propagation, 35
origins of practical, 25-26 in air, 129
ultrasonic scanning, 261. See also phased array ultrasonic testing systems in anisotropic materials, 40
and elastic constants, 320-321
acoustic holography, 300-301 extensions to other types of surface waves, 46-51
angle beam immersion techniques, 289-295 fluid coupled layered half spaces, 49
focused beam immersion techniques, 296-299 introduction, 36-40
immersion coupling devices, 267-269 in isotropic materials, 41-45
immersion test indication interpretation, 274-283 layered half spaces, 47-49
immersion testing of composite materials, 284-288 reflection at plane boundary in stress free media, 52-56
introduction to ultrasonic testing, 262-263 and scholte wave, 51
multiple-transducer systems, 419-420 transverse horizontal waves, 49-51
pulse echo immersion test parameters, 271-273 wave properties, 36-39
ultrasonic test techniques, 264-266 wave types, 39-40
water couplant characteristics, 270 ultrasonic wave reflection
ultrasonic signal processing, 87-89, 143, 183 anisotropic materials, 40
autocorrelation and cross correlation, 151-152 incident angles greater than critical angle, 55-56
averaging procedures, 151 incident angles less than critical angle, 54-55
clustering application, 168-170 incident longitudinal wave, 52-53
convolution and deconvolution, 149, 153-154 incident transverse horizontal mode, 53-54
data acquisition and analog-to-digital conversion, 147-149 incident transverse vertical mode, 54
data storage and presentation, 155 interfacial, in structural concrete, 486-487
data structure, 166-168 at plane boundary in stress free media, 52-56
digitization procedures, 148-149 transmission and reflection, 56
gating procedures, 149-150 ultrasonic wave speed, 482-483
pattern recognition principles, 164-173 ultrasound generation and detection, 59. See also laser based ultrasound;
sampling procedures, 147-148
signal acquisition and processing, 144-145 piezoelectric materials; transducers
signal classification, 144-146 air coupled transducers, 129-132
signal filtering, 152-153 electromagnetic acoustic transduction, 115-128
signal processing, 150-155 focused beam immersion techniques, 95-99
signal reception and conditioning, 85-86 generation and reception, 78-89
smoothing, 154-155 lamb waves, 100
space scattering diagrams, 168
ultrasonic spectroscopy, 146, 156-164

586 Ultrasonic Testing

optical detection of ultrasound, 109-111 water squirter systems, for ultrasonic immersion testing systems, 268
optical generation and detection, 107-114 advantages and limitations of, 501
optical generation of elastic waves, 107-109
phased arrays, 90-94 waveform digitizer, 189
piezoelectricity, 60-67 waveguides, 101
simple interferometric detection, 109-110 wavelength, 37
time delay interferometry, 110 wavelet transform
transduction, 68-77
ultrasonic guided waves, 100, 101-106 ultrasonic spectroscopy application, 162-163
velocity interferometry, 110 wave number, 36, 37
ultrasound testing, See ultrasonic testing waves, ultrasonic, 36-39
underwater applications
flooded member detection, 447-449, 453 propagation, 36-40. See also ultrasonic wave propagation
ultrasonic submarine detection, 25, 26, 28 properties, 36-39
ultrasonic testing, 61 speed, 36
ultrasonic testing of internal damage in wood pilings, 477 vector, 39
ultrasonic testing of offshore structures, 446-453 velocity, 36
underwater cabling, 449-451 welded joints
underwater transducers, 449 material production inspection in aerospace applications, 504-505
Unified Numbering System. See UNS number under name of metal, such as material test issues in aerospace applications, 495
welds
aluminum or steel angle beam contact testing, 219
United States Air Force angle beam ultrasonic immersion testing, 293
delta indirect pitch catch ultrasonic testing technique, 233-234
damage tolerance approach, 530-531 material test issues in aerospace applications, 495
units of measure, 30-32 phased array ultrasonic testing of tailored, 249
UNS (Unified Numbering System) number. See name of metal, such as ultrasonic field testing of bridges, 478-479
ultrasonic immersion testing interpretation of indications from rotor
aluminum or steel
utility applications. See also electric power applications wheels, 281-282
ultrasonic pulse echo contact testing, 225-228
ultrasonic tests of fasteners, 434 ultrasonic pulse echo immersion testing, 206
ultrasonic scanning, 90, 92-94
V ultrasonic transverse wave testing, 29
ultrasonic testing in marine industry, 542-543
vacuum ultrasonic testing in processing plants, 432, 433-434
ultrasonic testing with electromagnetic acoustic transducers, 127 ultrasonic testing of nuclear reactors, 461-465
ultrasonic testing of offshore structures, 446-447
valves ultrasonic testing with dual-element transducers, 235
ultrasonic inservice inspection of condensers in power plants, 459 ultrasonic testing with electromagnetic acoustic transducers, 118-120
wheels
velocity interferometric detection ultrasonic testing of railroad, 540
of ultrasound, 110 ultrasonic testing of railroad using moving electromagnetic acoustic

vibrational modes, 319-320 transducers, 126-127
vibration analysis, 12 wheel transducer technique, of immersion testing, 269
video amplifiers wind damage

ultrasonic testing application, 87, 89 ultrasonic field testing of bridges, 478
video detector window, 150
wiring insulation
ultrasonic testing application, 88-89
video display, 187 ultrasonic testing of space system, 519-521
VidigageTM, 29 wood
visual testing, 7-8
ultrasonic testing in infrastructure applications, 476-480
highway bridges, 476 wooden structures
voids
ultrasonic testing, 477-478
and acoustic microscopy, 544 wrinkles
angle beam contact testing, 217
material test issues in aerospace applications, 495 material test issues in aerospace applications, 495
straight beam contact pulse echo tests, 206 ultrasonic material production inspection in aerospace applications, 501,
structural concrete, 484
through-transmission ultrasonic testing, 266 502
ultrasonic testing of advanced materials, 385, 389 wrought alloys
ultrasonic testing of advanced structural ceramics, 363-364
ultrasonic testing of composite laminates, 380 ultrasonic testing, 400-405
ultrasonic testing of structural concrete, 481, 485 wrought aluminum. See also aluminum alloys
voltage. See also amplitude
and inverse piezoelectric effect, 61 ultrasonic testing, 406
ultrasonic testing transducers, 411
W wrought molybdenum alloy
acoustic parameters, 43
wall thickness eccentricity wrought nickel chromium alloy
ultrasonic testing of petroleum pipes, 442-443 acoustic parameters, 43

wall thinning Y
detection using nondestructive testing, 2
ultrasonic detection in chemical and petroleum applications, 435-436 yield strength
ultrasonic measurement, 331-333
water
acoustic parameters, 43 Young’s modulus
as couplant for ultrasonic contact testing, 223 relation to ultrasonic wave speed and other elastic constants, 319
as couplant for ultrasonic immersion testing, 263, 270 ultrasonic measurement, 319, 320
transverse ultrasonic wave attenuation for interface with steel, 47
ultrasonic interface transmission and reflection coefficients, 497 Z
ultrasonic wave attenuation as function of pressure, 270
ultrasonic wave attenuation as function of temperature, 266 zinc oxide
ultrasonic wavelength, 497 velocity dispersion of surface waves on silicon substrate, 49

water jet devices, for ultrasonic immersion testing systems, 268 zirconia
water level determination ultrasonic testing of coatings, 378-379

ultrasonic applications in marine industry, 543 zone lenses, 98

Index 587

Figure Sources

Chapter 6. Ultrasonic Pulse Echo
Contact Techniques

Figures 8-9 — Boeing Aerospace Company, Seattle, WA
[formerly Douglas Aircraft Company,
Long Beach, CA].

Figures 25b and 25c — General Electric Company,
Schenectady, NY.

Chapter 12. Electric Power
Applications of Ultrasonic Testing

Figures 1 and 3 — IHISw/Southwest Research Institute,
ISwT, San Antonio, TX.

Figures 2 and 6 — IHISw, San Antonio, TX.
Figures 5, 7, 11 — Olympus NDT, Waltham, MA.

Chapter 14. Aerospace
Applications of Ultrasonic Testing

Figures 30 to 45 — National Aeronautics and Space
Administration, Cleveland, OH. Works of the United
States government, not subject to copyright.

588 Ultrasonic Testing