3. mmz 2003
mmz 2003
Course Layout
Course Layout
Duration
Duration :
: 9.5 Days (Mon – Fri)
9.5 Days (Mon – Fri)
Start
Start :
: 8:30 am
8:30 am
Coffee Break
Coffee Break :
: 10:00 – 10:30 am
10:00 – 10:30 am
Lunch
Lunch :
: 12:30 – 1:30 pm
12:30 – 1:30 pm
Tea Break
Tea Break :
: 3:00 – 3:30 pm
3:00 – 3:30 pm
Day End
Day End :
: 5:00 pm
5:00 pm
Course Objective:
Course Objective: To train and prepare
To train and prepare
participants to obtain required skill and
participants to obtain required skill and
knowledge in Ultrasonic Testing and to meet the
knowledge in Ultrasonic Testing and to meet the
examination schemes requirements.
examination schemes requirements.
4. mmz 2003
mmz 2003
NDT
NDT
Most common NDT methods:
Most common NDT methods:
Penetrant Testing (PT)
Magnetic Particle Testing (MT)
Eddy Current Testing (ET)
Radiographic Testing (RT)
Ultrasonic Testing (UT)
Mainly used for
surface testing
Mainly used for
Internal Testing
5. mmz 2003
mmz 2003
NDT
NDT
Which method is the best ?
Which method is the best ?
Depends on many factors and conditions
Depends on many factors and conditions
6. mmz 2003
mmz 2003
Basic Principles of Ultrasonic
Basic Principles of Ultrasonic
Testing
Testing
To understand and
To understand and
appreciate the
appreciate the
capability and
capability and
limitation of UT
limitation of UT
7. mmz 2003
mmz 2003
Basic Principles of Ultrasonic Testing
Basic Principles of Ultrasonic Testing
Sound is transmitted in the material to be tested
The sound reflected back to the
probe is displayed on
the Flaw Detector
8. mmz 2003
mmz 2003
Basic Principles of Ultrasonic Testing
Basic Principles of Ultrasonic Testing
The distance the sound traveled can be displayed on the Flaw Detector
The screen can be calibrated to give accurate readings of the distance
Bottom / Backwall
Signal from the backwall
10. mmz 2003
mmz 2003
Basic Principles of Ultrasonic Testing
Basic Principles of Ultrasonic Testing
The presence of a Defect in the material shows up on the screen of
the flaw detector with a less distance than the bottom of the material
The BWE signal
Defect signal
Defect
11. mmz 2003
mmz 2003
The depth of the defect can be read with reference
to the marker on the screen
0 10 20 30 40 50 60
60 mm
12. mmz 2003
mmz 2003
Thickness / depth measurement
Thickness / depth measurement
A
A
B
B
C
C
The THINNER the material
the less distance the sound
travel
The closer the reflector
to the surface, the signal
will be more to the left of
the screen
The thickness is read from the screen
68
46
30
14. mmz 2003
mmz 2003
Ultrasonic
Ultrasonic
Sound : mechanical vibration
Sound : mechanical vibration
What is Ultrasonic?
Very High Frequency sound – above 20 KHz
20,000 cps
15. mmz 2003
mmz 2003
Acoustic Spectrum
Acoustic Spectrum
0 10 100 1K 10K 100K 1M 10M 100m
Sonic / Audible
Human
16Hz - 20kHz
Ultrasonic
> 20kHz = 20,000Hz
Ultrasonic Testing
0.5MHz - 50MHz
Ultrasonic : Sound with frequency above 20 KHz
16. mmz 2003
mmz 2003
DRUM BEAT
Low Frequency Sound
40 Hz
Glass
High Frequency
5 K Hz
ULTRASONIC TESTING
Very High Frequency
5 M Hz
17. mmz 2003
mmz 2003
Sound waves are the vibration of particles in solids
liquids or gases
Particles vibrate about a mean position
One cycle
Displacement
The distance
taken to
complete one
cycle
wavelength
wavelength
18. mmz 2003
mmz 2003
Properties of a sound wave
Properties of a sound wave
Sound cannot travel
Sound cannot travel
in
in vacuum
vacuum
Sound energy to be
Sound energy to be
transmitted /
transmitted /
transferred from one
transferred from one
particle to another
particle to another
SOLID LIQUID GAS
19. mmz 2003
mmz 2003
Sound
Sound
Wavelength :
Wavelength :
The distance required to complete a cycle
The distance required to complete a cycle
Measured in Meter or mm
Measured in Meter or mm
Frequency :
Frequency :
The number of cycles per unit time
The number of cycles per unit time
Measured in Hertz (Hz) or Cycles per second (cps)
Measured in Hertz (Hz) or Cycles per second (cps)
Velocity :
Velocity :
How quick the sound travels
How quick the sound travels
Distance per unit time
Distance per unit time
Measured in meter / second (m / sec)
Measured in meter / second (m / sec)
21. mmz 2003
mmz 2003
High Frequency Sound
High Frequency Sound
f
V
5MHz compression
wave probe in steel
mm
18
.
1
000
,
000
,
5
000
,
900
,
5
22. mmz 2003
mmz 2003
Frequency
Frequency
Frequency
Frequency :
: Number of cycles per
Number of cycles per
second
second
1 second
1 cycle per 1 second =
1 Hertz
18 cycle per 1 second
= 18 Hertz
3 cycle per 1 second =
3 Hertz
1 second 1 second
THE HIGHER THE FREQUENCY THE SMALLER THE
WAVELENGTH
23. mmz 2003
mmz 2003
Frequency
Frequency
1 Hz
1 Hz =
= 1 cycle per second
1 cycle per second
1 Kilohertz
1 Kilohertz =
= 1 KHz
1 KHz =
= 1000Hz
1000Hz
1 Megahertz
1 Megahertz =
= 1 MHz
1 MHz = 1000 000Hz
= 1000 000Hz
20 KHz = 20 000 Hz
5 M Hz = 5 000 000 Hz
24. mmz 2003
mmz 2003
Frequency
Frequency
1 M Hz 5 M Hz 10 M Hz 25 M Hz
Which probe has the smallest wavelength?
SMALLEST
LONGEST
Which probe has the longest wavelength?
= v / f
F
F
25. mmz 2003
mmz 2003
Wavelength and frequency
Wavelength and frequency
The higher the frequency the smaller the
The higher the frequency the smaller the
wavelength
wavelength
The smaller the wavelength the higher the
The smaller the wavelength the higher the
sensitivity
sensitivity
Sensitivity
Sensitivity :
: The smallest
The smallest
detectable
detectable flaw by the
flaw by the
system or
system or technique
technique
In UT the smallest detectable flaw is
In UT the smallest detectable flaw is ½
½
(half the wavelength)
(half the wavelength)
26. mmz 2003
mmz 2003
Which of the following compressional
Which of the following compressional
probe has the highest sensitivity?
probe has the highest sensitivity?
1 MHz
1 MHz
2 MHz
2 MHz
5 MHz
5 MHz
10 MHz
10 MHz
10 MHz
27. mmz 2003
mmz 2003
Acoustic Spectrum
Acoustic Spectrum
0 10 100 1K 10K 100K 1M 10M 100m
Ultrasonic
> 20kHz = 20,000Hz
Ultrasonic : Sound with frequency above 20 KHz
Sonic / Audible
Human
16Hz - 20kHz
Testing 0.5MHz - 50MHz
Very high frequency = Very small wavelength
28. mmz 2003
mmz 2003
Velocity
Velocity
The velocity of sound in a particular material is
The velocity of sound in a particular material is CONSTANT
CONSTANT
It is the product of
It is the product of DENSITY
DENSITY and
and ELASTICITY
ELASTICITY of the
of the
material
material
It will NOT change if frequency changes
It will NOT change if frequency changes
Only the wavelength changes
Only the wavelength changes
Examples:
Examples:
V Compression in steel
V Compression in steel : 5960 m/s
: 5960 m/s
V Compression in water
V Compression in water : 1470 m/s
: 1470 m/s
V Compression in air
V Compression in air : 330 m/s
: 330 m/s
STEEL WATER AIR
5 M Hz
29. mmz 2003
mmz 2003
Velocity
Velocity
4 times
What is the velocity difference in steel compared with in
water?
If the frequency remain constant, in what material does
sound has the highest velocity, steel, water, or air?
Steel
If the frequency remain constant, in what material does
sound has the shortest wavelength, steel, water, or air?
Air
Remember the formula
= v / f
30. mmz 2003
mmz 2003
Sound Waveforms
Sound Waveforms
Sound travels in different waveforms in
different conditions
•Compression wave
Compression wave
•Shear wave
Shear wave
•Surface wave
Surface wave
•Lamb wave
Lamb wave
31. mmz 2003
mmz 2003
Compression / Longitudinal
Compression / Longitudinal
Vibration and propagation in the same
Vibration and propagation in the same
direction / parallel
direction / parallel
Travel in solids, liquids and gases
Travel in solids, liquids and gases
Propagation
Particle vibration
32. mmz 2003
mmz 2003
Shear / Transverse
Shear / Transverse
Vibration at right angles / perpendicular to
Vibration at right angles / perpendicular to
direction of propagation
direction of propagation
Travel in solids only
Travel in solids only
Velocity
Velocity
1/2 compression (same material)
1/2 compression (same material)
Propagation
Particle vibration
33. mmz 2003
mmz 2003
Surface Wave
Surface Wave
Elliptical vibration
Elliptical vibration
Velocity 8% less than shear
Velocity 8% less than shear
Penetrate one wavelength deep
Penetrate one wavelength deep
Easily dampened by heavy grease or wet finger
Follows curves but reflected by sharp corners or
surface cracks
34. mmz 2003
mmz 2003
Lamb / Plate Wave
Lamb / Plate Wave
Produced by the manipulation of surface
Produced by the manipulation of surface
waves and others
waves and others
Used mainly to test very thin materials /
Used mainly to test very thin materials /
plates
plates
Velocity varies with plate thickness and
Velocity varies with plate thickness and
frequencies
frequencies
SYMETRIC ASSYMETRIC
35. mmz 2003
mmz 2003
Compression v Shear
Compression v Shear
Frequency
Frequency
0.5MHz
0.5MHz
1 MHz
1 MHz
2MHz
2MHz
4MHz
4MHz
6MHZ
6MHZ
Compression
Compression
11.8
11.8
5.9
5.9
2.95
2.95
1.48
1.48
0.98
0.98
Shear
Shear
6.5
6.5
3.2
3.2
1.6
1.6
0.8
0.8
0.54
0.54
The smaller the wavelength the better the
sensitivity
36. mmz 2003
mmz 2003
Sound travelling through a material
Sound travelling through a material
Velocity varies according to the material
Velocity varies according to the material
Compression waves
• Steel 5960m/sec
• Water 1470m/sec
• Air 344m/sec
• Copper 4700m/sec
Shear waves
• Steel 3245m/sec
• Water NA
• Air NA
• Copper 2330m/sec
37. mmz 2003
mmz 2003
Loses intensity
Loses intensity
due to
due to
Sound travelling through a material
Sound travelling through a material
Attenuation
Attenuation
• Sound beam comparable
to a torch beam
•Reduction differs for small
and large reflectors
• Energy losses due to
material
•Made up of absorption
and scatter
Beam Spread
38. mmz 2003
mmz 2003
Scatter
Scatter
The bigger the grain
The bigger the grain
size the worse the
size the worse the
problem
problem
The higher the
The higher the
frequency of the
frequency of the
probe the worse the
probe the worse the
problem
problem
1 MHz 5 MHz
39. mmz 2003
mmz 2003
Beam Spread
Beam Spread
The sound beam
spread out and the
intensity decreases
40. mmz 2003
mmz 2003
Beam spread and Attenuation combined
Beam spread and Attenuation combined
80%
FSH
40%
FSH
No attenuation,only beam
spread. 6dB reduction
80%
FSH
36%
FSH
Attenuation and beam
spread. 6dB+ reduction
41. mmz 2003
mmz 2003
Sound at an Interface
Sound at an Interface
Sound will be either transmitted across
Sound will be either transmitted across
or reflected back
or reflected back
Reflected
Transmitted
Interface
How much is reflected and
transmitted depends upon the
relative acoustic impedance of
the 2 materials
42. mmz 2003
mmz 2003
Acoustic Impedance
Acoustic Impedance
Definition
Definition
The Resistance to the
The Resistance to the
passage of sound
passage of sound
within a material
within a material
Formula
Formula
V
Z
Measured in
Measured in
kg / m
kg / m2
2
x sec
x sec
Steel
Steel 46.7 x 10
46.7 x 106
6
Water
Water 1.48 x 10
1.48 x 106
6
Air
Air 0.0041 x 10
0.0041 x 106
6
Perspex
Perspex 3.2 x 10
3.2 x 106
6
= Density , V = Velocity
43. mmz 2003
mmz 2003
% Sound Reflected at an
% Sound Reflected at an
Interface
Interface
reflected
Z
Z
Z
Z
%
100
2
2
1
2
1
% Sound Reflected + % Sound Transmitted = 100%
Therefore
% Sound Transmitted = 100% - % Sound Reflected
44. mmz 2003
mmz 2003
Sound at an Interface
Sound at an Interface
Sound will be either transmitted across
Sound will be either transmitted across
or reflected back
or reflected back
Reflected
Transmitted
Interface
How much is reflected and
transmitted depends upon the
relative acoustic impedance of
the 2 materials
45. mmz 2003
mmz 2003
How much sound is reflected at a steel to water
How much sound is reflected at a steel to water
interface?
interface?
Z
Z1
1 (Steel) = 46.7 x 10
(Steel) = 46.7 x 106
6
Z
Z2
2 (Water) =1.48 x 10
(Water) =1.48 x 106
6
reflected
%
100
48
.
1
7
.
46
48
.
1
7
.
46
2
reflected
%
100
18
.
48
22
.
45
2
reflected
%
88.09
100
93856
.
0
2
46. mmz 2003
mmz 2003
How much sound transmitted?
100 % - the reflected sound
Example : Steel to water
100 % - 88 % ( REFLECTED) = 12 % TRANSMITTED
The BIGGER the Acoustic Impedance Ratio
or Difference between the two materials:
More sound REFLECTED than transmitted.
48. mmz 2003
mmz 2003
Ultrasonic Displays
Ultrasonic Displays
A scan
A scan
The CRT (Cathode Ray Tube) display
The CRT (Cathode Ray Tube) display
The Horizontal axis :
The Horizontal axis :
Represents time base /
Represents time base / beam path length /
beam path length /
distance / depth
distance / depth
The Vertical axis :
The Vertical axis :
Represent the amount of
Represent the amount of sound energy
sound energy
returned to the crystal
returned to the crystal
49. mmz 2003
mmz 2003
Ultrasonic Displays
Ultrasonic Displays
B scan
B scan
The End View Display
The End View Display
B
50. mmz 2003
mmz 2003
Ultrasonic Displays
Ultrasonic Displays
A scan
A scan
The CRT (Cathode Ray Tube) display
The CRT (Cathode Ray Tube) display
The Horizontal axis :
The Horizontal axis :
Represents time base /
Represents time base / beam path length /
beam path length /
distance / depth
distance / depth
The Vertical axis :
The Vertical axis :
Represent the amount of
Represent the amount of sound energy
sound energy
returned to the crystal
returned to the crystal
51. mmz 2003
mmz 2003
Ultrasonic Displays
Ultrasonic Displays
C scan
C scan
The Plan View Display
The Plan View Display
C
52. mmz 2003
mmz 2003
Ultrasonic Displays
Ultrasonic Displays
D scan
D scan
The Side View Display
The Side View Display
D
