My talk to the Penn State student chapter of the Acoustical Society of America

1. John Coupland
coupland@psu.edu
@JohnNCoupland
Flicker: chotda

2. Delay line Sample Brass Plate
Electrical spike
Echo 1
Echo 2
0.2
Echo time
0.1
Signal /V
Echo amplitude
0.0
-0.1
Echo 1 Echo 2
Electrical spike
-0.2
0 5 10 15 20 25 30
Time / s

3. Oscilloscope trace
Amplitude=f(t)
FFT
Magnitude=f(frequency)
Phase=f(frequency)
Magnitude Phase
Lab View
Properties = f(frequency)

4. Ultrasonic Properties of a Fluid
Velocity (c) Attenuation ( )
amplitude (A)
0
0
distance (x)
or time (t)
c = d/t A = Ao e- x
c= f

5. Ultrasonic
Measurements
are Not Interesting
Flicker: jasonr611

6. Ultrasonic
property
Physical
constants
Correlation
FOOD
QUALITY

7. Velocity
2
c
i k Bulk modulus
K+4/3G
2 f E (K<<G)
2 1
c 1/”how many molecules there are
per unit volume and how hard is to
compress them”

8. Example: Position and Movement

9. • “The Lean-Meater can be thought of as
an electronic ruler. Ultrasonic pulses
sent into the animal are reflected back
to the instrument from tissues of
interest. The times until these echoes
are received are translated into
distances in mm. Measurements are
non-invasive—no piercing of the skin
with the consequent danger of
infection. The animals are neither hurt
nor irritated.”
http://www.rencocorp.com/lean-meater.htm

10. Position and Movement
(2)
(3)
(1)
Doppler image adapted from: L. Wang , K. L. McCarthy, M. J.
McCarthy, Food Research International 37 (2004) 633–642

11. Example: Liquid Composition
Flicker: mikeyexists

12. Blending Operation

13. Composition Measurement by Ultrasonic Velocity
1800
Ultrasonic velocity / ms-1
1700
1600
1500
0 10 20 30 40 50
Concentration / wt%
( Sodium chloride,  ethanol,  glycerol,  sucrose, and  tomato ketchup)

14. 1600
Ultrasonic velocity /ms-1
1500
1400
1300 T1 T2
0 20 40 60 80 100
Temperature /°C
() distilled water, () 20% sucrose solution, () corn oil, and a fine corn oil in water
emulsion () =10%, () =50%.

15. Olive Oil Processing Waste
J. Benedito *, A. Mulet, G. Clemente, J.V. Garcıa-Perez, Food Research International 37 (2004) 595–601

16. Example: Fat Melting
Flicker: dishevld

17. 100% solid
Solid Fat Content Brittle solid
Hard solid
Spreadable solid
Liquid
100% liquid
cold hot
Temperature

18. Tristearin, tripalmitin or
mixtures in paraffin
oil, 25°C, 1 MHz
dc 1
3.1 ms
d
(McClements and
20% Povey, 1987)
0%

19. Chocolate
2200
2000
Velocity /ms -1
1800
1600
1400
1200
0 10 20 30 40 50 60
Temp /oC

20. Crystallization cell for emulsions, fats and oils
Chirp
Transducers
silvana.martini@usu.edu

21. Example: Particle Sizing
Flicker: bitzi ☂ ion-bogdan dumitrescu

22. 35
30
Emulsion 3
25
Frequency /%
Emulsion 5
20
15
Emulsion 1
10
5
0
0.1 1 10
Diameter / m

23. Scattering Mechanisms in Emulsions
Compression Compression Compression

24. Scattering from an Emulsion
1460 0.03
1450
-1
Np
0.02
c /ms
1440
0.01
1430
0.00
-7 -6 -5 -4 -3 -2 -1 0 1 2 3
log rf0.5

25. 90
1480
80
70
1475
60
/Npm-1
-1
50
c /ms
1470
40
1465 30
20
1460 10
0 1 2 3 4 5 6 0 1 2 3 4 5 6
f /MHz f /MHz
Velocity Spectra Attenuation Spectra Fig. 4b
Fig. 4a

26. Particle Size Analysis
Concentrated dispersion characterization
Dispersion Technology Inc DT-1200
Dukhin AS, Goetz PJ, Advances in Colloid and Interface Science 92 (1-3): 73-132, 2001

27. Viscosity
Flicker: Charlie P Barker

28. Impedance Measurements
2
Ir ( Z 2 Z1 )
R 2
Ii ( Z 2 Z1 )
z c
Reflection coefficient
is a measure of
acoustic dissimilarity

29. Ultrasonic Viscometry
Normalized ultrasonic reflectance
s20
1.00
s60
s200
s600
s2000
0.98
0.96
0.94
0.01 0.1 1 10 100
/ Pa.s

30. Advantages
Flicker: monkeyc.net

31. Disadvantages
John Couplan
coupland@ps
Flicker: Or Hiltch @JohnNCoup