ABS

 

Bubble Size Measurement

The ABS Acoustic Bubble Spectrometer®© is an acoustics based device that measures bubble size distributions and void fraction of bubbles in liquids. The initial efforts to develop the technology were funded by Small Business Innovation Research (SBIR) awards from the National Science Foundation. Present efforts are driven by commercial applications and by the request of customers using the instrument.

Principle :
The device extracts the bubble population from acoustical measurements made at several frequencies. It consists of a set of two transducers/hydrophones connected to a computer. A data acquisition board controls the hydrophones' signal generation and acquisition. The PC is also used for analysis of the data and provides, using DYNAFLO's software, the sound speed and attenuation as a function of frequency.
The bubble population can be obtained from these measurements by a solution of two Fredholm Integral Equations of the first kind. These equations are ill-posed and are a challenge to solve - especially when the data has noise. In our research, we developed novel algorithms that are able to accurately solve these equations using a constrained optimization technique.
The instrument can provide the data in near real time, thus making it suitable for process applications. The bubble distributions from the ABS have been validated by comparison with micro-photography.

Advantages:
Compared to optics based devices, the ABS is inexpensive and easy to use. In addition, the acoustic technique is very sensitive to bubbles and is not fooled by the presence of particulate matter which are optically not readily distinguishable.


   
If you are interested in purchasing a transducer or hydrophone or for more information on ABS, please contact us.  

 

The portable ABS Acoustic Bubble Spectrometer®© system

 


Research & Development in Applied Sciences


DYNAFLOW, INC.



 

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DYNAFLOW, INC.
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Last Updated: 5/08/2008

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