Water Level Sensing in a Steel Vessel Using A0 and Quasi-Scholte Waves

Abstract EN

This paper presents a water level sensing method using guided waves of A0 and quasi-Scholte modes.

Theoretical, numerical, and experimental studies are performed to investigate the properties of both the A0 and quasi-Scholte modes.

The comparative study of dispersion curves reveals that the plate with one side in water supports a quasi-Scholte mode besides Lamb modes.

In addition, group velocities of A0 and quasi-Scholte modes are different.

It is also found that the low-frequency A0 mode propagating in a free plate can convert to the quasi-Scholte mode when the plate has one side in water.

Based on the velocity difference and mode conversion, a water level sensing method is developed.

For the proof of concept, a laboratory experiment using a pitch-catch configuration with two piezoelectric transducers is designed for sensing water level in a steel vessel.

The experimental results show that the travelling time between the two transducers linearly increases with the increase of water level and agree well with the theoretical predictions.