Phase Shift Based Level Sensing using two guided Wave Mode T (0, 1) and F(1,1) on a thin Waveguide

Abstract

This paper reports a novel ultrasonic guided wave-based waveguide sensor for liquid level measurement which is critical for process controls in industries. A thin stainless wire with a varying cross-section (cylinder and rectangular end) is selected as the waveguide sensor in which all three fundamental wavemode L (0,1), T (0,1), and F (1,1) are excited and received by a single shear transducer. We validated the suitability of this waveguide for continuous level measurement experiments in the laboratory conditions. Level measurement experiments were carried out in inviscid fluid (water) and the fluid level is monitored/extracted by tracking the change in time of flight ((δTOF) of the excited torsional wavemode T(0,1) and flexural wavemode F(1,1) in the waveguide that is directly related to the fluid level in the probed media. The presented technique is suitable for enhanced level measurement using two wavemodes simultaneously. The versatility of this technique enables its application for remote measurements in a wide range of applications Keywords: Guided wave, Waveguide, Sensor, Level Measurement