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A Double Transducer for High Precision Ultrasonic Time-Domain Reflectometry Measurements.

Stade S, Hakkarainen T, Kallioinen M, Mänttäri M, Tuuva T - Sensors (Basel) (2015)

Bottom Line: A double transducer described in this study eliminates the need for a separate reference transducer because in the double transducer the reference measurement is included in the design of the transducer holder.Two sensors in the same holder require less space.Other advantage is that the double transducer can be placed near the measurement target and hence the local sonic velocity can be determined.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Separation Technology, School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, Lappeenranta FI-53851, Finland. stade@lut.fi.

ABSTRACT
Membrane fouling, where unwanted particles accumulate on the membrane surface and reduce its permeability, causes problems in membrane filtration processes. With ultrasonic time-domain reflectometry (UTDR) it is possible to measure the extent of membrane fouling and hence take actions to minimize it. However, the usability of UTDR is very limited to constant filtration conditions if the sonic velocity, which has a great impact on UTDR measurement accuracy, is unknown. With a reference transducer the actual sonic velocity can be measured. This requires another transducer to be installed in the module, where there may be only limited space or the module dimensions may not be suitable for the reference transducer. A double transducer described in this study eliminates the need for a separate reference transducer because in the double transducer the reference measurement is included in the design of the transducer holder. Two sensors in the same holder require less space. Other advantage is that the double transducer can be placed near the measurement target and hence the local sonic velocity can be determined.

No MeSH data available.


Results of the fouling experiment. The flux and the fouling layer thickness were measured during the filtration.
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sensors-15-15090-f007: Results of the fouling experiment. The flux and the fouling layer thickness were measured during the filtration.

Mentions: The fouling test results are shown in the Figure 7 and Figure 8. As can be seen from the Figure 7, the fouling layer started to grow when the filtration started and the flux started to decrease. The filtration continued over the night and next day the filtration was ended and the membrane was analysed with the SEM. The fouling layer can be clearly seen from the SEM image (Figure 8).


A Double Transducer for High Precision Ultrasonic Time-Domain Reflectometry Measurements.

Stade S, Hakkarainen T, Kallioinen M, Mänttäri M, Tuuva T - Sensors (Basel) (2015)

Results of the fouling experiment. The flux and the fouling layer thickness were measured during the filtration.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541822&req=5

sensors-15-15090-f007: Results of the fouling experiment. The flux and the fouling layer thickness were measured during the filtration.
Mentions: The fouling test results are shown in the Figure 7 and Figure 8. As can be seen from the Figure 7, the fouling layer started to grow when the filtration started and the flux started to decrease. The filtration continued over the night and next day the filtration was ended and the membrane was analysed with the SEM. The fouling layer can be clearly seen from the SEM image (Figure 8).

Bottom Line: A double transducer described in this study eliminates the need for a separate reference transducer because in the double transducer the reference measurement is included in the design of the transducer holder.Two sensors in the same holder require less space.Other advantage is that the double transducer can be placed near the measurement target and hence the local sonic velocity can be determined.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Separation Technology, School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, Lappeenranta FI-53851, Finland. stade@lut.fi.

ABSTRACT
Membrane fouling, where unwanted particles accumulate on the membrane surface and reduce its permeability, causes problems in membrane filtration processes. With ultrasonic time-domain reflectometry (UTDR) it is possible to measure the extent of membrane fouling and hence take actions to minimize it. However, the usability of UTDR is very limited to constant filtration conditions if the sonic velocity, which has a great impact on UTDR measurement accuracy, is unknown. With a reference transducer the actual sonic velocity can be measured. This requires another transducer to be installed in the module, where there may be only limited space or the module dimensions may not be suitable for the reference transducer. A double transducer described in this study eliminates the need for a separate reference transducer because in the double transducer the reference measurement is included in the design of the transducer holder. Two sensors in the same holder require less space. Other advantage is that the double transducer can be placed near the measurement target and hence the local sonic velocity can be determined.

No MeSH data available.