Diseño de un tubo de impedancia para ensayos de absorción acústica de materiales

Abstract

Commercial impedance tubes are very expensive and hinder the development of research into new materials, especially those derived from plant fibers. Therefore, the objective is to design a low-cost impedance tube following standards such as ISO 10534-2 and ASTM E 1050-98. The importance of this work lies in providing users with an economical and high-quality option. The design of two impedance tubes was established, one for low-frequency testing and the other for high frequencies. Following the methodology, the overall system was divided into mechanical, electronic, and software design. Once the three designs were finalized, construction drawings for the tube and electronics were established. Subsequently, the designs were implemented to perform the acoustic characterization of coconut fiber samples. It was found that the absorption capacity of this fiber increases with increasing frequency, consistent with other studies. Furthermore, an economic analysis was performed, showing an implementation cost of $3494.11. Finally, it is concluded that by following the standards, an instrument with a good price-quality ratio can be designed, and that its implementation is viable and reproducible. Keywords: acoustic impedance, sound-absorbing materials; acoustic characterization; ISO 10534-2, ASTM E 1050-98