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The Scanning Acoustic Microscope (known as "SAM")
is used to produce high resolution internal images of materials and components.
USL acoustic microscopes operate in the "pulse echo" mode, in which
short sound pulses are transmitted into the sample and the returning echoes are
monitored and evaluated. By scanning the ultrasonic transducer over the sample,
an acoustic image of the internal structure is formed. This can be done in as
little as a few seconds.
The resolution of an acoustic microscope - that is the
smallest feature which can be imaged - is dependent on the frequency used. As a
guide, a test at 50MHz is able to image features down to about 30 micrometres in
diameter. For two dimensional features such as disbonds and delaminations, these
can be imaged when their "through thickness" dimension is less than 1
micrometre. This makes acoustic microscopy ideal for detecting such features,
where alternative methods such as X ray inspection are generally not effective.
USL offers a range of SAM systems to suit a wide variety of
materials and components. The first USL SAM system was installed over 14 years
ago and current equipment takes advantage of USL's continuous development in
mechanical scanners, electronics and software. The range is based around two
principal types - the SAM350 and the ICAM.
SAM350 is used for general purpose applications in laboratory
and small scale production environments - ICAM is configured specifically for
high speed inspection of integrated circuit assemblies. Further details are
available by clicking on the links above - the following table compares the two
systems.
 Typical
acoustic microscope images scanned at frequencies from 10 to 50MHz are
illustrated here. Clockwise, starting from the top left these show:
1. A brazed joint with artificial defects at the interface
2. Fatigue damage at a fixing hole in a composite material
3. Inclusions in steel
4. A bonded joint on a special purpose brake pad.
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ICAM |
SAM350 |
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SCANNER |
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Scan area (X,Y) |
350 x 250mm |
350 x 350mm |
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Z axis travel |
50mm |
200mm |
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Tank size |
380 x 290 x 50mm |
630 x 570 x 300mm |
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Resolution |
0.005mm |
0.0125mm |
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Scanning speed |
Up to 3 metres/sec
(15 lines per second at 25x25mm scan size)
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50mm/sec
(1-2 lines per second at 25x25 mm scan size)
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Drive system |
DC motors and ballscrews. Encoders for closed loop
control |
Stepper motors and ballscrews. (Encoders optional at
extra cost) |
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MOTOR DRIVE |
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Type |
Integated Baldor / PMAC DC motor drive |
Separate 3 axis stepper motor drive unit |
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COMPUTER |
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CPU |
Pentium 600MHz |
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RAM |
64Mbyte |
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Storage |
HDU 8Gbyte min
Rewriteable CD drive |
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Graphics |
SVGA 1024 x 768 x 256 colours
17" monitor
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ULTRASONICS |
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Pulser receiver |
USL PR20 and PR50 |
USL PR20 or PR50
(Second PR is optional)
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Pulser
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Spike and square wave pulse
0 - 600V
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PR20 Square wave
PR50 Spike pulse
0-600V
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Frequency range |
15 - 75MHz |
PR20 1 - 25MHz
PR50 15 - 75MHz
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Gain |
63dB |
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Mode |
Pulse echo and pitch catch |
Pulse echo standard.
Pitch catch with 2nd P-R installed
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DATA ACQUISITION |
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A - D board |
USL 100MHz, 8bit single shot
Sampling up to 8GHz
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Digital Signal Processing |
USL DSP100 |
Processing in software
DSP100 as an option
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Monitor Gates |
Amplitude, time and phase |
Amplitude and time |
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Number of gates |
8 simultaneous |
One
(8 with DSP option)
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Gate trigger |
Main bang and interface |
Main bang and interface |
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Gate resolution |
10 nanosecs |
10 nanosecs |
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ICAM |
SAM350 |
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SOFTWARE |
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RF/A scan display |
Update rate 15/20Hz, user selectable window |
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Features |
Display of multiple image files
C scan and B scan modes
Menu control of all functions
Motion control utilities
Joystick axis control
Palette selection and user editing
On screen measurements
Image zoom, pan and scroll
Full RF acquisition and processing - "Volume
Scan"
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Step and repeat |
- |
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Imaging modes |
A, B and C scan
Step and repeat multi view
Pulse echo and through transmission
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A, B and C scan
Pulse echo and double through transmission
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TRANSDUCERS |
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Standard supply |
25 and 50 MHz, PVdF
Through transmission
receiver
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25 and 50 MHz, PVdF |
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Optional |
75 MHz
15MHz
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From 0.5 to 50MHz, depending on application |
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PRINTER |
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Standard |
HP or Canon A4 inkjet |
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Optional |
A3 inkjets
Grey scale or colour video copiers
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OPTIONAL ITEMS |
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Mechanical |
Operator desk unit |
Turntables (200 and 300mm diameter)
Other rotary scanners
Probe manipulator
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Computer |
Other storage options |
Other storage options |
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Ultrasonics |
Pulser receivers up to 400MHz |
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Data acquisition |
500MHzHz and 1GHz
A-D converter
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Software |
Other Windows based software packages available for
compatibility with customers existing equipment - please enquire. |
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PHYSICAL |
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Overall size |
Scanner and electronic module
600x600x1500mm (WxDxH)
Includes computer, but excludes monitor |
Scanner 750x820x700mm
(WxDxH)
Electronic modules
2 at 600x600x150mm
Excludes computer and monitor
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Weight |
280kgs total |
Scanner 90kgs |
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Power |
110/220/240
Single phase, 13A
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110/220/240
Single phase, 13A
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