Application of a surface-acoustic-wave device for measurement of liquid flow rate

Author

Joshi, Shrinivas G. ; Jin, Yu

Author_Institution

Dept. of Electr. & Comput. Eng., Marquette Univ., Milwaukee, WI, USA

Volume

37

Issue

5

fYear

1990

Firstpage

475

Lastpage

477

Abstract

The use of a surface-acoustic-wave (SAW) device to measure the flow rate of liquids is described. A delay-line stabilized SAW oscillator heated to a suitable temperature above ambient is cooled by the flowing fluid. This results in a change in the oscillator frequency. The frequency of a 68-MHz oscillator operated at 9 degrees C above ambient is found to vary by more than 40 kHz for variation in water flow rate from 0 to 0.8 ml/min. Attractive features of this device include the ability to measure very low flow rates (less than 0.1 mu l/min) and direct digital output. However, since this is a thermal type of flow sensor, the temperature of the fluid will be slightly elevated during its passage through the flow cell. The device should be useful in applications where low flow rates have to be monitored.<>

Keywords

acoustic delay lines; flow measurement; nonelectric sensing devices; surface acoustic wave devices; 68 MHz; H/sub 2/O; delay-line stabilized SAW oscillator; direct digital output; liquid flow rate; low flow rates; oscillator frequency; surface-acoustic-wave device; thermal type flow sensor; Acoustic propagation; Chemical sensors; Fluid flow; Fluid flow measurement; Frequency; Oscillators; Substrates; Surface acoustic wave devices; Surface acoustic waves; Temperature;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/58.105254

Filename

105254