~
Ultrasonic20K/cps
-(transducer)
-
-(wave speed)(attenuation)
()
()
()
()
-
.
T/R
transducer(Panametrics V389 )
Sample
Guide
LECROY LT-342
Ultrasonic pulser/receiver(Panametrics 5058PR)
PC
Ultrasonic measurement system
-
.
Water
Sponge
T/R
0.5MHz transducer (Panametrics V389 )
Sample
Guide
LECROY LT-342
Ultrasonic pulser/receiver(Panametrics 5058PR)
PC
Underwater ultrasonic measurement system
Water tank
Digital Oscilloscopes
LECROY 9304A200MHz
PANAMETRICS 5058PR
Volt signal (mV)
V1(1)
V2(2)
(3)
t 1 t 2 Time(s)
12
2tt
dC
=
C
EC =
= fC
peak to peak
peak to peak
)exp( xAA ox =
( )( )
=
xpp
opp
VV
xln1
neper/m
peak topeakvolt
peak to peakvolt
meter
( )opp
V
( )xpp
V
x
Parsevals theorem
= dFdttf 22 )()(
Haugh1993
Sarkar and Wolfe1983
Mizrach1989
50kHz500kHz
Finney1968
224 LfE =
Vb E=
Vd )21)(1()1(
+
= E
Garrett &Furry(1972)
Mizrach1998
spectral analysis
Upchurch et al.1985
spectral analysis
Upchurch et al.1985
(Haugh, 1993)
,
FFT
)
(Haugh, 1993)
0.2
()
= 345.86 sg - 340.96R2 = 0.5721
0
5
10
15
20
25
30
0.99 1.00 1.01 1.02 1.03 1.04 1.05 1.06
Specific gravity
Atte
nuat
ion
coef
ficie
nt (n
eper
/m)
Regression analysis of specific gravity vs. attenuation coefficient for fresh samples
CCD
8
10
12
14
16
18
20
0 5 10 15 20 25 30
Attenuation coefficient (neper/m)
Brix
(%)
line of disorder
Evaluating disorder line of Chiin Hwang mango
by attenuation coefficient for ultrasonic echo technology
0
5
10
15
20
25
30
-5 0 5 10 15 20 25 30 35 40 45
Young's modulus(Kg/cm2)
Atte
nuat
ion
coef
ficie
nt(n
eper
/m)
The distribution of attenuation coefficient and Youngs modulus by 0.5MHz underwater ultrasonic
766mV 1656mV20.9 neper/m 8.1 neper/m
Mo =0.082 Mo =0.392
(Zhang et al.,1994
(Zhang et al.,1994
(Zhang et al.,1994
FFT
(Zhang et al.,1994
FFT
65
56 (arrow)
,()( distended left anterior talofibular
pouch )
(RT)(EU)(MT)(LT)(UT)(AE)
()
LASER-ULTRASONICS()
(couplant)EMAT(capacitive)(air-coupled)(laser-ultrasonics)(LUT)
LASER-ULTRASONICS()
LASER-ULTRASONICS()
()