Construção de um tubo de impedâncias e teste através do método de função de transferência

Abstract

When designing an environment or an equipment it is often necessary to consider its acoustic conditions, such as the amount of sound that transmitted to nearby environments, as there is often a need for sound insulation, such as in industries, theaters, houses, apartments, cars, airplanes, etc. However, to do the acoustic dimensioning some physical quantities must know, such as acoustic impedance, acoustic absorption and sound transmission. The objective of this work was the development of an impedance tube, which will have the function of acoustic impedance measurement of different materials also the coefficient of acoustic absorption. The equipment’s development aims to supply a deficit of equipment of acoustics and vibrations for the course of mechanical engineering of the Universidade Tecnológica Federal do Paraná. The impedance tube is available for use in UTFPR. To confirm the efficiency of this impedance tube, samples of different materials with acoustic impedance values and acoustic absorption coefficient already known have used for comparison purposes. For the measurement of these physical quantities, the technique chosen was the "Transfer Function Method" using the multi-microphone technique, which provides the results in a shorter time than the traditional stationary wave (SWR) technique.