For your own safety and that of the equipment, please
read the following instructions thoroughly before using this ultrasonic device and its accessories.
The slits in the device are for ventilation and must not
be covered to avoid overheating of the equipment. We
recommended that the feet on the device be used.
Ensure that the specified operating voltage and safety
measures are observed.
Never try to insert objects through the ventilation slits
since this could lead to short circuits or electric shocks.
Connect only the ultrasonic transducer supplied by 3B
Scientific GmbH to the "PROBE" sockets. Caution: the
transmitting transducer may experience voltage pulses
as high as 300 V.
Be aware that this is laboratory equipment and not a
medical appliance. The ultrasonic sensors are not to
be used on people or animals.
6
blbmbnbobpbq
9
1 Start point for time-dependent amplification
2 Trigger slope (rise time) for time-dependent amplification
3 Width of time-dependent amplification
4 Threshold for time-dependent amplification
5 Transmitter power
6 Receiver gain
7 Power supply
8 Mains switch
9 Receiver unit
7
bl Probe connection for reflection mode
or receiver in transmission mode
bm Reflection/transmission mode changeover switch
8
bn Probe connection for transmission mode
bo Transmitter unit
bp Clocking unit (time-dependent amplifier)
bq Connector sockets for oscilloscope
br Signal output A scan (LF signal)
bs Signal output (HF signal)
bt Signal output for trigger signal
bu Signal output for time-dependent amplifier ramp
dependent amplifier can be viewed separately. The gain
for the amplification of the received signal can be adjusted in 5-dB steps from 0 to 35 dB. The transmitter
power can be adjusted in 10-dB steps from 0 to 30 dB.
For time-dependent amplification, the start point, the
rise time, the threshold and the width can all be continuously adjusted up to a maximum gain of 35 dB.
Also included is the ASH control software for Microsoft
Windows. This allows you to measure amplitude and
timing differentials. It also supports the simultaneous
display of HF signal and amplitude signal so that, unlike with conventional A-image equipment, the wave
nature of ultrasound can be demonstrated. An additional chart simultaneously shows the form of and
change in the time-dependent amplification. Other
software options include: manually guided B-images;
time-motion mode; FFT on a selected signal segment;
zoom function; changeover between time and resolution depending on the speed of sound, which can also
be adjusted; switching between measuring ranges; data
export and print capability; automatic mode display
(transmission or refection).
2.2.Ultrasonic transducer
2.2.1. Ultrasonic transducer 1 MHz U10015
For examinations at greater depth or examinations involving high power and low depth resolution, 16-mm
piezo-ceramic disc in cast metal housing, preset for
water propagated sound, one cable with frequencycoded snap-in plug.
2.2.2. Ultrasonic transducer 4 MHz U10017
For examinations requiring maximum depth resolution at shallow depth, 16-mm piezo-ceramic disc in
cast metal housing, preset for water propagated sound,
1-m cable with frequency-coded snap-in plug.
1. Introduction
Ultrasonic echoscopy (also called sonography) has developed into one of the key procedures for medical
examination and materials technology. Although there
is a confusingly wide range of ultrasonic devices produced for various applications, all of them rely on the
same basic principle of emitting a mechanical wave
and recording the reflections in an echogram.
2. Components
2.1. Ultrasonic echoscope controls U10010
The U10010 echoscope is an ultrasonic A-image device with an output for pure pulse echo operation and
an extra output and converter for operation with two
ultrasonic transducers for transmission measurements.
The device is equipped with a parallel interface for
connection to transfer data to a PC.
To make the principle behind the device clearer, the
individual components, receiver, transmitter and time-
2.3.Accessories
2.3.1. Acrylic block with holes U10027
For determining speed of sound and attenuation of
an ultrasonic signal in acrylic (polyacrylate), for pinpointing discontinuities, and investigating imaging errors caused by sound shadows or ground echoes, frequency-dependent resolution capacity and display of
a manual B image. To investigate resolution, both the
1-MHz and the 4-MHz transducers are required. Polished polyacrylate block with drilled holes of various
diameter for simulating discontinuities at various distances from the surface of the block.
2.3.2. Equipment set for longitudinal and transverse
waves U10020
For investigating the propagation of longitudinal and
transverse (shear) waves in solid bodies and determining elastic constants (shear modulus, modulus of elasticity and Poisson number) of these bodies. Also for
determining ultrasonic attenuation in fluids by means
12
Page 3
of time-dependent amplitude measurement with
moveable reflector.
Ultrasound is first passed vertically through a body
under test placed in a trough filled with water. Only
longitudinal waves are propagated through the body.
The transmission amplitude of these is recorded. In
rotating the body to ever greater angles, the amplitude of the longitudinal waves decreases and transverse waves are increasingly propagated through the
body. These appear in the amplitude domain as a second peak.
From the angle where total reflection of the longitudinal waves takes place, the speed of the longitudinal
waves can be calculated. The speed of transverse waves
can be calculated from the angle where the maximum
transmission amplitude for transverse waves occurs. If
the body is rotated further, total reflection of the transverse component may also occur depending on the
magnitude of the speed of sound in proportion to that
in the surrounding fluid.
From the two speeds of sound, the elastic constants
(shear modulus, modulus of elasticity and Poisson
number) for the body under test can be calculated.
Acrylic (included in the scope of delivery), aluminum
and polyoxymethylene (POM) plates are available as
test bodies. The speed of transverse waves in acrylic
(polyacrylate) is almost exactly the same as in water.
In aluminum the speed is greater and in POM it is
smaller than in water.
Set consists of sounding trough, acrylic test plate in
holder with protractor scale and two transducer holders for 1-MHz or 4-MHz ultrasonic transducers that allow for precise positioning of the transducers on the
sounding trough.
2.3.3. Aluminum plate with protractor scale U10022
Accessory for longitudinal and transverse waves equipment set for investigating the propagation of transverse
waves in metals and for determining the elastic constants such as shear modulus, modulus of elasticity and
Poisson number for aluminum; high quality reflector
(large reflection coefficient in water) and therefore easyto-measure signal amplitudes for attenuation measurements in liquids (e.g. water, cooking oil, glycerine).
individual echoes analyzed. The result is a shifting of
the median frequency to lower frequencies since the
higher frequency components are more strongly attenuated.
2.3.6. Set of 3 cylinders U10026
Polished polyacrylate cylinders for determining speed
of sound and attenuation of ultrasound in acrylic.
Measurements can be made using reflection mode or
transmission mode.
2.3.7. Heart valve model U10029
Twin chamber with rubber membrane and pressure
regulator for demonstrating the action of heart valves
using the time-motion method. During the experiment,
the membrane chamber produces an image similar to
that produced by a valve of a beating heart in an electrocardiogram as used for medical diagnosis.
2.3.8. Model of a single breast with benign tumor
Imitation breast made of silicon with a simulated benign tumor for demonstrating B-image mode.
3.Software
3.1. Program operation
As soon as the program is started, the measuring equipment is immediately activated. The user interface is
shown in the illustration above. In the top part of the
screen, the A-image signal, the current position of the
markers (vertical red and green lines), the frequency
of the receiving transducer that is connected and the
current mode (reflection/pulse echo or transmission).
The markers can be positioned using the mouse (the
mouse cursor changes when the markers are to be
moved).
2.3.4. Polyoxymethylene (POM) plate in test holder
with protractor scale U10023
Accessory for longitudinal and transverse waves equipment set for investigating the propagation of transverse
waves in plastic and for determining the elastic constants such as shear modulus, modulus of elasticity and
Poisson number for POM.
2.3.5. Reflection plate U10025
Polished acrylic plate for investigating multiple echoes and measuring frequency-dependent attenuation.
The 4-MHz transducer is particularly suited for measurements of this kind. Initially an echo image with at
least three echoes is recorded and the spectrum of the
The scale for the time axis (time measurement) can be
switched to display distance (depth measurement)
["Time"/"Depth" buttons]. An entry for the speed of
propagation as required for calculation can be made
using the Settings option in the menu (default: 1000
m/s). The UP-DOWN button pairing at the left-hand edge
of the screen is for changing the amplitude resolution
(top) and shifting the zero-axis (bottom).
13
Page 4
The constant updating of the A image can be suspended
(Freeze) by using the "Stop" button and restarted using the "Start button". When the image is frozen, the
FFT button becomes active. If this is clicked, the amplitude spectrum of the segment of signal bounded by
the markers is displayed in a new window (see illustration below.)
At the same time, a measurement function using the
mouse is activated (crosshair cursor). Frequency and
amplitude are displayed at the position where the
mouse is situated. The form can be printed (standard
printer under Windows), or the spectrum can be saved
(as an ASCII table) using the Export function.
The "Zoom" button magnifies the display of a selected
depth range. Position and width of the range are set
by moving the sliders in the middle of the screen with
the mouse. The "Full" button causes the "Zoom" function to be deactivated again.
The button marked "100"/"200" allows the measuring
range (maximum time or resolution) to be switched
between 100 µs and 200 µs. The "A" [A image], "HF"
[High-frequency signal] and "All" [both signals] settings
allow you to select the form in which the signal should
be displayed.
In the central region of the screen, the characteristics
for time-dependent amplification are shown including all parameters (start point, rise time, width, threshold). At the bottom of the window, status information
is displayed. Among the items shown here are the time
or the depth represented by the current marker positions. The difference between the red and green markers is displayed in yellow. The current transmitted level
and primary gain are shown at the bottom left. The
bottom right gives the amplitude of the received voltage at the mouse cursor position (the center of the
crosshair.)
3.2. Menu functions
FilePrint FormPrints the window
(form) to the
current printer
ExportExports the
measured values as
an ASCII table to
a text file (columns:
Time, HF data,
A image, TGC),
ExitExit the program
Settings Speed ofEntry for the speed
soundof sound to allow
correct display of
depth (default:
1000 m/s)
PortSelection of LPT
port for
communication with
controlling PC
Type ofDurationAxis = time
meas.(default)
DepthAxis = depth
DisplayA-scanDisplays the A
image (A mode)
HF dataDisplays the HF
signal (Echo)
AllDisplays both signals
(HF echo and A line/
envelope)
B image Activates the form for displaying a
B image (B-mode image)
M-mode Activates the form for displaying an
M-mode image
4. Suggested experiments
4.1. Wave nature of ultrasound
With the aid of the software, it is possible to display a
signal corresponding to a reflection, e.g. between an
acrylic block and air, in HF mode (high frequency oscillation), in A mode (amplitude component = envelope of HF signal) and in both modes at once. This can
convey to the student which signal gives rise to a typical A image. Below is a screenshot of the software user
interface showing the measured signal at the top and
the settings for the amplifier underneath it.
14
Page 5
4.2. Determining the frequency of the transducer
in use
From the initial echo of the transducer or from a lightly
and the edge of the body allows the longitudinal speed
of sound cL to be calculated from the measured time t
as follows
damped reflection, it is possible to determine the distance between two maxima in the high-frequency signal oscillation with the aid of the zoom function. This
s
2
c
=
L
t
involves placing the measuring cursors at two adjacent
peaks of the high frequency signal as shown in the
above screenshot. The time difference can then be read
directly from the status bar. With this information, the
frequency of the transducer being used may be calculated (in this case 1/1µs = 1 MHz).
4.3. Longitudinal speed of sound in test bodies
An ultrasonic transducer is attached to test bodies made
of various materials and the time between the emission of a pulse and the reception of an echo reflected
from a boundary layer is measured (see photograph
below). Knowing the distance s between the transducer
Some results of measurements involving different ma-
terials and geometries are shown in the table below.
MaterialTime∆tDistance∆sSpeed of sound∆c
[µs][µs][mm][mm]longitudinal [m/s][m/s]
AcrylicRod 184.10.4112.90.2268518
Rod 2112.50.6151.00.2268418
Block Length111.30.4150.00.2269513
Width30.30.440.20.2265348
Height59.40.479.80.2268725
Standard value2610-2750
PVCBlock Length84.90.498.00.2230916
Width76.80.487.60.2228117
Height70.30.480.70.2229619
Standard value2220-2380
(1)
4.4. Attenuation of sound in test bodies
Using the measuring cursor for determining amplitude
in the ASH program, the amplitude A of the echo from
the rear surface of two bodies of identical but different size can be measured. Applying the law of attenuation to these measurement gives
A = A0 e
–αx
(2)
which can be rearranged to give the sound attenuation coefficient
α
=
2
α
1
Ln
−
xx
()
1221
A
A
(3)
A1 is the amplitude for a body of width x1 and A2 is that
for a body of width x2. The factor of 1/2 in equation (3)
emerges from the fact that sound must traverse the
distance twice when the reflection method is used. If a
transmitter-receiver arrangement is employed, the factor is omitted.
In all cases care should be taken to ensure that the
amplifier settings are kept identical as far as possible
in order to achieve reproducible results.
Thus the thicknesses of the objects should not differ
greatly. The sound attenuation coefficient in (3) is fre-
quency-dependent so that the frequency used for the
measurement should always be quoted along with the
result. The theoretical frequency-independent absorp-
tion coefficient
α
is given by (4) (where υ is the fre-
0
quency of the ultrasonic wave):
α
α
=
2
ν
(4)
15
Page 6
Unfortunately, in most bodies and fluids there is a large
scattering component to the attenuation coefficient.
Since scattering is dependent on the ratio of the wavelength to the size of the scattering object, this can lead
to wide variations in the frequency dependence of the
attenuation arising from (4).
When comparing with standard published values, it
should be noted that the values are usually given in
dB/cm so that the value for α results from (3) thus:
α
[1 / cm] or [neper / cm] =
αα
dB cm
[]
Lg e
208 686
()
dB cm//
[]
=
.
(5)
4.5. Attenuation of sound in fluids
By measuring inside a fluid container with a movable
reflector it is possible to plot a curve of the reflected
amplitude for various values.
An external program can then derive the attenuation
coefficient α by finding a fit for the exponential function in (3) or more simply identifying a linear fit to a
line that matches (3) when it is rearranged in the form
(6):
yax
=
A
0
α
Ln
2
xx
=−
()
A
i
i0
(6)
where A0 is the amplitude of the peak closest to the
transducer. All subsequent measurements (i) are related
to this value so that the measuring error at greater distances becomes much smaller. If the speed of sound
in the fluid has already been determined (e.g. by using
the transmission method where measuring both
lengthways and across the width eliminates the effect
of the container's walls) and entered into the program,
the distances of the reflector from the transducer can
be read off directly from the software (Depth setting).
Attenuation of sound in water is too weak to measure
any alteration in amplitude over a distance of around
20 cm. The following diagram shows a graph as measured for sunflower oil.
By setting the amplifier appropriately, the entire available path may be used for measurements. Using a frequency of 1 MHz gives a value of about 0.5 dB/cm for
the attenuation coefficient, which is close to the published value of 1 dB/cm for frequencies of 1 – 5 MHz.
4.6. Frequency-dependent attenuation
Frequency-dependent attenuation can be studied very
well using a thin acrylic plate (thickness 1 – 2 cm
approx., see photograph).
Since parallel surfaces give a series of multiple echoes
when the transducer is placed straight against them,
the frequency components of individual echo pulses
can be investigated using the FFT function built into
the program. The following illustration shows the corresponding FFT analyses. It can clearly be seen that
higher frequencies are attenuated more acutely as the
distance traveled through the plate increases. Thus the
median frequency (the frequency component of the
highest amplitude) becomes shifted.
16
Page 7
The rise time, threshold and start point of the ampli-
fier can all be adjusted so that the individual echoes
all appear to be of equal magnitude. The time-depend-
ent amplifier thus compensates for the attenuation in
the material. Variations in width and point of action
can emphasize areas at different depths or even filter
certain depths out. An example is shown in the follow-
ing diagram.
4.7. Time dependent amplification
The plate used in 4.6 can also be used to demonstrate
the time-dependent amplification method that is often employed, particularly in medicinal applications.
The damping visible in the display above is just about
eliminated with the time-dependent amplification set-
tings used in the display below.
17
Page 8
4.8 Frequency dependence of resolution
Two small discontinuities situated close together in a
specially manufactured test body (see section 4.9) can
be used to demonstrate the frequency dependence of
resolution.
The discontinuities are investigated using a 1-MHz and
a 4-MHz transducer and the ability to separate the two
locations is compared for the two frequencies. The
amplitude signals for both frequencies are shown in
the following diagrams. The top one is the display for
the 1-MHz transducer and the lower is for the 4-MHz
transducer.
The software converts the amplitude scan into a twodimensional brightness display.
At each of the various discontinuities, the focus of the
ultrasonic transducer, the position resolution and image errors (such as sound shadows) can all be displayed.
4.10. Time-motion mode (M-mode)
So-called M-mode allows ultrasonic reflections from
moving boundary layers to be displayed. This can be
used, e.g. in an echocardiogram, to investigate the
valves of the heart. The heart itself can be simulated
using the heart valve model (U10029) with a rubber
membrane caused to move by a ball-shaped bellows.
4.9. Manually guided B image
A test body with discontinuities can be used along with
the built-in B-Image software feature to demonstrate
how a B (brightness) image is generated from an amplitude signal.
The 1-MHz transducer (U10015) is slowly and evenly
guided over the test body as in the following illustration.
The corresponding software option (M-mode) allows
the movements to be shown as a two-dimensional display.
18
Page 9
The M-mode image basically corresponds to a displace-
Cc
TF
=
()
1
2
sin
φ
C
E
L
=
−
+
()−()
ρ
υ
υυ
1
112
ment-time graph, so that the speed of movement can
be determined from the rise time.
4.11. Transmission coefficient and transverse
speed of sound
With an experiment set-up like that shown in Figure 2
(transducer in transmission mode attached to a waterfilled trough containing a rotatable plate with a specified thickness of 1 cm), by turning the plate it can be
demonstrated that when an ultrasonic wave passes
from a fluid to a solid body at a non-perpendicular
angle, both longitudinal and transverse waves are excited.
Since transverse sound waves are produced by shearing and their speed is lower than that of longitudinal
waves, the following regions arise (example with
acrylic):
Angle of incidence 0°: only a peak for longitudinal waves
possibly with multiple reflections
Small angle of incidence (<=10°): multiple reflections
vanish, amplitude decreases
Angle of 10° - 30°: peaks for both longitudinal and
transverse waves
Angle >30°: only transverse waves remain with amplitude maxima at an angle of incidence of about 40°.
Amplitude becomes smaller at increasing angles
The amplitude in transmission mode or, by measuring
the transmission in the absence of the plate, the amplitude transmission coefficient can now be calculated
for both longitudinal and transverse waves (see following diagram).
Since the transmission of transverse waves through the
plate is greatest at a transmission angle of 45°, the
maximum in the transverse amplitude curve may be
used to determine the angle of incidence Φ and thus
the transverse speed of sound by means of the follow-
ing equation
(7)
where cF is the speed of sound in water (1480 m/s).
Fig. 17 shows the measurement results for a test body
composed of 1 cm thick acrylic. For an amplitude
maximum at 40°, equation (7) gives the speed of trans-
verse waves to be approximately 1600 m/s. The pub-
lished value is 1450 m/s. Determining the angle more
precisely would certainly lead to greater accuracy in
this case.
Separation into longitudinal and transverse amplitudes
is possible due to the differences in time of travel re-
sulting from the large differences in speed of longitu-
dinally and transversely propagated waves. Even with
a plate of only 1 cm thickness, the transverse waves
are sufficiently delayed to be measured (see following
illustration).
The speed of transverse waves allows the shear modu-
lus (torsion modulus) G to be calculated:
G
C
=
T
ρ
(8)
The modulus of elasticity E (Young's modulus) for the
body can be calculated from the longitudinal speed of
sound if the cross-sectional contraction coefficient (υ-
-Poisson number) is known:
(9)
When cross-sectional expansion is negligible (for thin
rods):
E
C
=
L
ρ
(10)
where ρ is always the density of the body
19
Page 10
If cT and cL are known, the Poisson number υ can also
be calculated by means of equation (11):
−
υ
C
C
()
L
=
T
υ
−2112
(11)
4.12. Combination of B image and A scan for
testing materials
To demonstrate the testing of materials, a body with
invisible discontinuities is provided. A manually guided
B image can be used to gain an initial idea of where
the discontinuities lie. The precise coordinates can then
be determined and plotted with the help of an A scan.
5. Technical details
5.1 Ultrasonic echoscope U10010
Frequency range:1 MHz to 5 MHz
Measuring mode:can be switched between
pulse-echo and
transmission modes
Transmitted signal: Dirac pulse
(<1µs, 10 V – 300 V)
Transmitter power: 0 30 dB, in 10 dB steps
Gain:0-35 dB, in 5 dB steps
Time-dependent
amplifier:continuously adjustable
threshold, start point, rise time
and duration, up to 30 dB gain
Connections:TGC signal, trigger, NF signal,
HF signal all via BNC
sockets (Var. Ex)
Computer port:Sub D-25 socket on LPT
via male-male cable
Sampling rate:10 MHz per channel
Dimensions:256 x 257 x 156 mm
Mains voltage:115 V / 230 V switchable
Power consumption: max. 20 VA
5.2. Ultrasonic transducer 1 MHz U10015
Dimensions:65 mm x 27 mm ∅
5.3. Ultrasonic transducer 4 MHz U10017
Dimensions:65 mm x 27 mm ∅
5.4. Acrylic block with holes U10027
Dimensions:150 x 80 x 40 mm
5.5 Equipment set for longitudinal and transverse
ultrasound propagation U10020
Sound trough:200x100x60 mm
Protractor scale:360°, with 5° divisions
Acrylic plate:70 x 45 x 10 mm
Dimensions:104 x 75 x 50 mm
5.6 Aluminum block with protractor scale U10022
Protractor scale:360°, with 5° divisions
Aluminum block:70 x 45 x 50 mm
Dimensions:104 x 75 x 50 mm
5.7. Polyoxymethylene (POM) plate with protractor
scale U10023
Protractor scale:360°, with 5° divisions
POM plate:70 x 45 x 10 mm
Dimensions:104 x 75 x 50 mm
5.8. Reflection plate U10025
Dimensions:80 x 40 x 10 mm
5.9. Set of 3 cylinders U10026
Dimensions:40 mm x 40 mm ∅
80 mm x 40 mm ∅
120 mm x 40 mm ∅
5.10. Heart valve model U10029
Dimensions:160 mm x 70 mm
5.11. Model of a single breast with benign
tumor L55/1
Model breast made of silicon rubber with simulated
benign growth
6. Bibliography
Millner, R.: Ultraschalltechnik – Grundlagen und
Anwendung. Physik-Verlag, 1987
Kuttruff, H.: Physik und Technik des Ultraschalls. S.
Hirzel-Verlag Stuttgart, 1988
Krautkrämer, J., Krautkrämer, H.: Werkstoffprüfung mit
Ultraschall. Springer Verlag, 1968
Weiterführend:
Sutilov, V.A.: Physik des Ultraschalls. Akademie-Verlag,
Berlin, 1984
Morse, P.M., Ingard, K.U.: Theoretical Acoustics.
McGraw-Hill Book Company, New York, 1968
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com • Technical amendments are possible
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