teori dasar ultrasonik
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Introduction to Ultrasonic Testing SD 218 SLAMET WALUYO PT. MULTI KHARISMA PERKASA2007Krautkramer NDT Ultrasonic Systems
Straight beam probehousing socket
dampingblock crystal workpiece
matchingelement protecting face (probe delay) Sound pulseKrautkramer NDT Ultrasonic Systems
Angle beam probedamping blocks housing
socket perspex wedge (probe delay)
crystal
workpiece
Sound pulseKrautkramer NDT Ultrasonic Systems
3
Sound field
N = near field length
near field
far field
= angle of divergenceacoustical axis (central beam)Krautkramer NDT Ultrasonic Systems
Flaw detection
Krautkramer NDT Ultrasonic Systems
Flaw detection10 20 30 40
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Flaw detection10 20 30 40
Krautkramer NDT Ultrasonic Systems
Bad flaw orientation
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Improper flaw location
crackKrautkramer NDT Ultrasonic Systems
Angle reflection10 20 30 40
crack
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Angle reflection
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Vertical, near surface flaw
10
20
30
40
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Tandem technique (top)a1 T5 1015
5 10
15
R
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Tandem technique (middle)a2 T5 1015
5 10
15
R
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Tandem technique (bottom)a3T5 1015
5 10
15
R
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Improper flaw orientation
10
20
30
40
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Perfect flaw orientation
10
20
30
40
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Flaw detectability with improper flaw orientationreflected sound waves5 1015
sound beam flat defectKrautkramer NDT Ultrasonic Systems
Flaw distance
s
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Principle of transit time measurementfinish signal (echo) transmitter start signal (pulse) sound transit path work pieceKrautkramer NDT Ultrasonic Systems
Stopwatch probe transit time measurement
CRT / A-scan display
0
2
4
6
8
10
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Priciple, transmission pulsetransmittertransmission pulse
sound wave starts at crystal
work piece probe
light point
0
2
4
6
8
10
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Priciple, sound wave in the workpiecetransmitter sound wave
work piece probe
0
2
4
6
8
10
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Priciple, sound pulse at the back walltransmitter
work piece probe
0
2
4
6
8
10
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Priciple, sound pulse at the coupling surfacetransmitter
work piece probe
0
2
4
6
8
10
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Priciple, echo display and 2nd runtransmitter
work piece probe back wall echo
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Probe delay
2
4
6
8
10
electrical zero (initial pulse)
mechanical zero (surface)
crystalprobe protecting faceKrautkramer NDT Ultrasonic Systems
Probe delayelectical zero (initial pulse)
probe delay (wedge)
0
2
4
6
8
10
sound wave
mechanical zero (surface)
work pieceKrautkramer NDT Ultrasonic Systems
Flaw location and echo displayflaw
work piece probe back wall echo flaw echo
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Flaw location and echo displayflaw
work piece probe
back wall echoflaw echo 0 2 4 6 8 10
Krautkramer NDT Ultrasonic Systems
Flaw location and echo displayflaw
work piece probe
flaw echo
back wall echo
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Flaw location and echo displayflaw
work piece probe back wall echoflaw echo covered by initial pulse
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Flaw location and echo displayflaw
work piece probe back wall echo: without with flaw 0 2 4 6 8 10
Krautkramer NDT Ultrasonic Systems
Flaw location and echo displayflaw
work pieceprobe
flaw echo sequence
0
2
4
6
8
10
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Dead zone
dead zone
0
2
4
6
8
10
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Near surface detectability with angle beam pobes
10
20
Krautkramer NDT Ultrasonic Systems
TR-probe / dual crystal probetransmitter socketacoustical barrier crystal
receiver socketdamping blocks
delay
Krautkramer NDT Ultrasonic Systems
Probe delay with TR-probesIP
BE
0
2
4
6
8
10
TR-probe
work pieceKrautkramer NDT Ultrasonic Systems
Cross talk at high gainIPcross talk echo0 2 4 6
BEflaw echo
8
10
TR-probe
flaw
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Range calibration
0
2
4
6
8
10
div.
0
50
100 mm steel, L
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Calibration block 1 with angle beam probes5 10 15
70 60
45
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1st echo from circular section
5
10
15
0
2
4
6
8
10
100 mm
Krautkramer NDT Ultrasonic Systems
Echo sequence from 100 mm radius
5
10
15
0
2
4
6
8
10
100 mm 200 mm 300 mm
Krautkramer NDT Ultrasonic Systems
25 mm radius of calibration block 2this wave will be absorbed !
s 1 = 25 mm s 2 = 100 mm s 3 = 175 mm etc.Krautkramer NDT Ultrasonic Systems
50 mm radius of calibration block 2
s 1 = 50 mm s 2 = 125 mm s 3 = 200 mm etc.Krautkramer NDT Ultrasonic Systems
100 mm range calibration on K2
5
10
15
0 0
2
4
6
8
10
100 mm steel
Krautkramer NDT Ultrasonic Systems
Flaw locations = kRs = sound path k = scale factor R = screen reading015 10 5
2
4
6
8
10
swork piece reflector
Krautkramer NDT Ultrasonic Systems
Flaw location with angle beam probesSound entry point a s = probe angle s = sound path a = surface distance d = depth d flaw location a = ssin d = scos projection point "flaw triangle"
Krautkramer NDT Ultrasonic Systems
Flaw location with angle beam probesa = surface distance a' = reduced surface distance x = x-value = distance: index point front edge of probe
x15 10 5
a a'
s
dreflector
work piece
Krautkramer NDT Ultrasonic Systems
Flaw location with an angle beam probe on a plate
a15 10 5
T
s
d = apparent depth
apparent flaw location
Krautkramer NDT Ultrasonic Systems
Flaw location with an angle beam probe on a plated' = apparent depth d = real depth T = work piece thicknessa = s sin d = s cos d = 2T - d
a15 10 5
T
s
d d'
real flaw location
apparent flaw locationKrautkramer NDT Ultrasonic Systems
Large defects parallel to the scanning surface
Krautkramer NDT Ultrasonic Systems
Scanning the edge of the defect
Flaw echo drops to 50% of its maximum value
Krautkramer NDT Ultrasonic Systems
Flaw sizes and echo amplitudes
IP
R
BE
IP
R
BE
IP
R
BE
0
2
4
6
8
10
0
2
4
6
8
10
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Flaw distances and echo amplitudesIP R BE
0
2
4
6
8
10
IP
R
BE
0
2
4
6
8
10
IP
R BE
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Defect evaluation by comparison - 1
instrument gain: G = 34 dB
IP
F
BE80 %
F
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Defect evaluation by comparison - 2
IP
R
BE
0 instrument gain: 34 dB
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Defect evaluation by comparison - 3
IP
RE BE
+ 8 dB
0instrument gain: 42 dB
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems
Krautkramer NDT Ultrasonic Systems