Reduction of systematic measurement deviation in acoustic absorption measurement systems
01 Jan 2020-
TL;DR: In this paper, the authors describe several measures to reduce systematic measurement deviation by decreasing or compensating the effects of dissipative effects in the fluid, such as diffraction and unwanted transmission at acoustic reflectors or waveguide boundaries.
Abstract: Motivation One major issue in the realization of acoustic absorption measurement systems is the fact that the absorption caused by dissipative effects in the fluid, such as viscosity, is superimposed by other losses resulting from the sound propagation in the respective measurement system. Examples for these effects are the spreading of the acoustic signal caused by diffraction and unwanted transmission at acoustic reflectors or waveguide boundaries. Unwanted reflected signals from planar surfaces included in the measurement system for constructive reasons may also interfere with the measurement. In this contribution, we describe several measures, which aim to reduce systematic measurement deviation by decreasing or compensating the aforementioned effects.
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01 Jan 2004
TL;DR: The quartz crystal is introduced as a microgravimetric sensor to present the reader an application of the piezoelectric phenomenon, which will be dealt with along the following chapters.
Abstract: The topic of the following chapter is relatively difficult and includes different areas of knowledge. The piezoelectric phenomenon is a complex one and covers concepts of electronics as well as most of the areas of classical physics such as: mechanics, elasticity and strength of materials, thermodynamics, acoustics, wave’s propagation, optics, electrostatics, fluids dynamics, circuit theory, crystallography etc. Probably, only a few disciplines of engineering and science need to be so familiar to so many fields of physics. Current bibliography on this subject is vast though dispersed in research publications, and few of the books on this topic are usually compilations of the authors’ research works. Therefore, they are not thought for didactic purposes and are difficult to understand, even for postgraduates. The objective of this chapter is to help understand the studies and research on piezoelectric sensors and transducers, and their applications. Considering the multidisciplinary nature, this tutorial’s readers can belong to very different disciplines. They can even lack the necessary basic knowledge to understand the concepts of this chapter. This is why the chapter starts providing an overview of the piezoelectric phenomenon, doing consciously initial simplifications, so that the main concepts, which will be progressively introduced, prevail over the accessories. The issues covered in this chapter must be understood without the help of additional texts, which are typically included as references and are necessary to study in depth specific topics. Finally, the quartz crystal is introduced as a microgravimetric sensor to present the reader an application of the piezoelectric phenomenon, which will be dealt with along the following chapters.
251 citations
"Reduction of systematic measurement..." refers background in this paper
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...Field simulations [5] show that increasing the aperture of the cone-shaped mount to 60◦ significantly decreases the occurrence of additional signals....
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TL;DR: An apparatus for the measurement of the speed of sound based on the pulse-echo technique is presented andspeed of sound data are presented with an uncertainty between 0.02% and 0.1%.
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17 citations
"Reduction of systematic measurement..." refers background or methods in this paper
...measurement set-up [1] with two reflectors and the propagation...
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16 citations