Phase Shift Based Level Sensing using two guided Wave Mode T (0, 1) and F(1,1) on a thin Waveguide
25 Oct 2020-
TL;DR: In this paper, a novel ultrasonic guided wave-based waveguide sensor for liquid level measurement is presented, which is suitable for enhanced level measurement using two wavemodes simultaneously.
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
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01 Nov 2021
TL;DR: In this article, the authors study the propagation of shear horizontal (SH) guided wave in a strip waveguide and its interaction with the notch in the waveguide through simulation studies.
Abstract:
Surface temperature mapping is crucial for the monitoring and control of an object of interest, such as furnace, reactor pipes carrying hot fluids, or a component under a temperature-dependent process. While the use of waveguides for temperature measurement is well documented in literature, the attachment of the waveguide to a metallic component poses challenges. These include the relationship between the local waveguide temperature and that of the metal component, and wave leakage into the component. In this paper, the authors study the propagation of shear horizontal (SH) guided wave in a strip waveguide and its interaction with the notch embodiments in the waveguide. The effects of the type of notch and its depth on the SH mode characteristics are investigated through simulation studies. The mode of attachment of the waveguide to the metal component is by means a slot made in the component. The area of contact between the waveguide and metal component is optimized such that there is minimum wave leakage into the bulk material. Based on the simulation results, a waveguide strip is fabricated and used to monitor the local surface temperature of a test metal component. The waveguide is calibrated by correlating the time of flight (ToF) shift in the waveforms against reference temperature values. Thereafter, the instantaneous temperature of the metal component is determined from the calibration equations. A set of experimental trials are performed to check for repeatability. The experiments are conducted in near steady-state conditions for better accuracy in the measurements.
3 citations
TL;DR: In this article , an ultrasonic waveguide technique using U-shaped configurations to measure the fluid level was reported. But the level measurement experiments were performed based on the drop in amplitude and change in time of flight of the received sensor signals.
Abstract: This paper reports an ultrasonic waveguide technique using U-shaped configurations to measure the fluid level. The longitudinal L(0,1) wave mode was propagated in the waveguide using through-transmission (TT) and pulse-echo (PE) techniques simultaneously using a single shear transducer. Initially, we used the Finite Element Method (FEM) to study the waveguide's wave propagation behavior while immersed in various fluids. Develop the level sensor using the waveguide’s first and second pass signals, corresponding to TT and PE. We have performed the level measurement experiments based on the drop in amplitude and change in time of flight of the received sensor signals. Studied the sensor’s sensitivity using TT1, PE1, TT2, and PE2 signals (1 and 2 represent first and second pass signals, respectively) with different fluid levels (petrol, water, castor oil, and glycerin). A comparison study was performed between straight waveguides using PE and U-shaped waveguides using TT techniques to find the limitations of waveguide sensors. During level-sensing experiments, the average error for U-shaped and straight waveguides was identified as 3.5% and 5.6%, respectively. We studied signal attenuation from straight and U-shaped waveguide sensors based on the sensor surface and dead-end region. In the designed U-shape waveguide, only the wave leakage effect was considered, avoiding the dead-end reflection during the immersion of the sensor in liquid and allowing for more fluid depth measurements. In addition, the U-shaped waveguide was further used for fluid-level sensing using three wave modes [L(0,1), T(0,1), and F(1,1)] simultaneously. This sensor can monitor fluid levels in hostile environments and inaccessible regions of power plants, oil, and petrochemical industries.
TL;DR: In this paper , an ultrasonic waveguide technique using U-shaped configurations to measure the fluid level was reported. But the level measurement experiments were performed based on the drop in amplitude and change in time of flight of the received sensor signals.
Abstract: This paper reports an ultrasonic waveguide technique using U-shaped configurations to measure the fluid level. The longitudinal L(0,1) wave mode was propagated in the waveguide using through-transmission (TT) and pulse-echo (PE) techniques simultaneously using a single shear transducer. Initially, we used the Finite Element Method (FEM) to study the waveguide's wave propagation behavior while immersed in various fluids. Develop the level sensor using the waveguide’s first and second pass signals, corresponding to TT and PE. We have performed the level measurement experiments based on the drop in amplitude and change in time of flight of the received sensor signals. Studied the sensor’s sensitivity using TT1, PE1, TT2, and PE2 signals (1 and 2 represent first and second pass signals, respectively) with different fluid levels (petrol, water, castor oil, and glycerin). A comparison study was performed between straight waveguides using PE and U-shaped waveguides using TT techniques to find the limitations of waveguide sensors. During level-sensing experiments, the average error for U-shaped and straight waveguides was identified as 3.5% and 5.6%, respectively. We studied signal attenuation from straight and U-shaped waveguide sensors based on the sensor surface and dead-end region. In the designed U-shape waveguide, only the wave leakage effect was considered, avoiding the dead-end reflection during the immersion of the sensor in liquid and allowing for more fluid depth measurements. In addition, the U-shaped waveguide was further used for fluid-level sensing using three wave modes [L(0,1), T(0,1), and F(1,1)] simultaneously. This sensor can monitor fluid levels in hostile environments and inaccessible regions of power plants, oil, and petrochemical industries.
References
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Book•
01 Sep 2004
TL;DR: In this article, the theory of elasticity was introduced and basic formulas and concepts in complex variables in the theory and application of wave propagation were discussed. But the authors did not consider the effects of wave scattering on the wave propagation experiments.
Abstract: Preface 1. Introduction 2. Dispersion principles 3. Unbounded isotropic and anisotropic media 4. Reflection and refraction 5. Oblique incidence 6. Wave scattering 7. Surface and subsurface waves 8. Waves in plates 9. Interface waves 10. Layer on a half space 11. Waves in rods 12. Waves in hollow cylinders 13. Guided waves in multiple layers 14. Source influence 15. Horizontal shear 16. Waves in an anisotropic layer 17. Elastic constant determination 18. Waves in viscoelastic media 19. Stress influence 20. Boundary element methods Bibliography Appendices A. Ultrasonic nondestructive testing principles, analysis and display technology B. Basic formulas and concepts in the theory of elasticity C. Basic formulas in complex variables D. Schlieren imaging and dynamic photoelasticity E. Key wave propagation experiments Index.
2,570 citations
"Phase Shift Based Level Sensing usi..." refers background in this paper
...In a cylindrical waveguide, three families of modes exist , longitudinal (L), torsional (T) and flexural (F) that propagate in the axial direction (z) of cylindrical coordinate system (r, and z) [24]....
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Book•
19 Jul 2013
TL;DR: This chapter discusses applications of Interface Measurement, Proximity Sensing, and Gaging Applications, and Theory and Measurement Techniques, as well as special Topics, including Elastic Moduli Applications.
Abstract: Introduction. Scope of Applications. Theory and Measurement Techniques. Flow Applications. Temperature Applications. Density Applications. Interface Measurement, Proximity Sensing, and Gaging Applications. Elastic Moduli Applications. Other Parameters--Special Topics. Historical Notes and Anecdotes. References. Index.
167 citations
"Phase Shift Based Level Sensing usi..." refers background in this paper
...Level measurement is critical in many process industries [1,2]....
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...From the literature it was observed that the Time of flight based (TOF) based level sensing will provide accurate level sensing of the surrounding medium when compared to the attenuation-based sensing [2,5]....
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...Specifically, ultrasonic guided wave-technique sensor [2, 11, 12] has an added advantage in contrast to the conventional ultrasonic level sensors which uses electromagnetic waves eg: guided wave radar [4]....
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TL;DR: In this paper, the state of the art of ultrasonic sensors and their advantages and disadvantages are discussed and commercial examples of applications in the food, chemical and pharmaceutical industries are described.
Abstract: Continuous process monitoring in gaseous, liquid or molten media is a fundamental requirement for process control. Besides temperature and pressure other process parameters such as level, flow, concentration and conversion are of special interest. More qualified information obtained from new or better sensors can significantly enhance the process quality and thereby product properties. Ultrasonic sensors or sensor systems can contribute to this development. The state of the art of ultrasonic sensors and their advantages and disadvantages will be discussed. Commercial examples will be presented. Among others, applications in the food, chemical and pharmaceutical industries are described. Possibilities and limitations of ultrasonic process sensors are discussed.
166 citations
TL;DR: The possibility of using ultrasonic guided waves for monitoring the cure process of epoxy resins is investigated and the numerical methods to relate these to the material properties of the curing resin are presented.
Abstract: The possibility of using ultrasonic guided waves for monitoring the cure process of epoxy resins is investigated. The two techniques presented use a wire waveguide which is partly embedded in the resin. The first technique is based on the measurement of attenuation due to leakage of bulk waves into the resin surrounding the waveguide. The second technique measures the reflection of the guided wave that occurs at the point where the waveguide enters the resin. Both the attenuation and the reflection coefficient change significantly during cure, and the numerical methods to relate these to the material properties of the curing resin are presented in this paper. The results from the modeling are experimentally verified and show good agreement. The applicability of each testing method is discussed, and typical cure-monitoring curves are presented.
41 citations
TL;DR: In this paper, the main parameters involved in the magnetostrictive delay line (MDL) operation are illustrated and the physical effects which can be utilized for the development of sensing devices are analyzed.
Abstract: The main parameters involved in the magnetostrictive delay line (MDL) operation are illustrated in this paper. Accordingly, the physical effects which can be utilized for the development of sensing devices are analyzed. Such physical effects, namely being modification of the pulsed and biasing magnetic fields as well as modification of the mechanical characteristics of the MDLs, have been used in order to develop various kinds of sensors. These sensors correspond to the measurement of length, linear and angular displacement, vibration, velocity, acceleration, force, stress, pressure, torque and magnetic field. All the above mentioned sensors can be formed in arrays by using MDLs as transducing means and analog multiplexers, with an array resolution and mapping area of the order of 1 mm and 1 m respectively. Thus, the gap between miniaturized array sensors and fiber optic array sensors, which have the ability of array resolution and mapping area of the order of 1 μm 1 mm and 1 m l Km respectively, is covered. Two and three dimensional cordless digitizers, as well as two dimensional force digitizers, have been developed due to these properties.
35 citations