Flowmeters are widely used in various industrial fields, and the measurement method is divided into two ways, direct measurement and indirect measurement. In general, the sensing principles of common indirect flowmeters are based on magnetic, ultrasonic, vortex, thermal, and so on. However, each of these flowmeters has its own limitations in actual application; especially, most of them cannot perform the immediately plug-in measurement. In the study, we use a strain gauge attached to tube wall and a 630 nm laser incident on the metal wire of strain gauge to evaluate the flow rate of fluid in tube by its scattering light generated from the edge of metal wire. Therein, an optical receiver can be used to sense the intensity difference and its frequency from the scattering light due to the shift of wire edge. In addition, the resistance difference and its fluctuated frequency on strain gauge can be used to correct the evaluation error of flow rate due to the deformation of outer tube. In the experiment, a common strain gauge and a diode laser were used to detect the resistance difference of strain gauge and the light intensity difference scattered from its wire edge, and their fluctuated frequency were also recorded to parameterize the evaluation of flow rate.
[1]
Ultrasonic Blood Flow Measurement in Haemodialysis
,
1970,
British medical journal.
[2]
F. Durst,et al.
Laser Doppler measurements in two-phase flows
,
1976
.
[3]
J. Hansen,et al.
Light scattering in planetary atmospheres
,
1974
.
[4]
M. Reader-Harris,et al.
Discharge coefficients of Venturi tubes with standard and non-standard convergent angles
,
2001
.
[5]
A. Kolin,et al.
An Electromagnetic Flowmeter. Principle of the Method and its Application to Bloodflow Measurements
,
1936
.
[6]
Ben Chic Yen,et al.
Open-Channel Flow Equations Revisited
,
1973
.