Qualification of the acoustic insulation laboratory of the Federal University of Santa Maria according to the international standard ISO 140

Abstract

The article discusses the qualification of the Acoustic Isolation Laboratory at the Federal University of Santa Maria according to the International Standard ISO 140. The laboratory conducted 40 tests on a single wall to determine the repeatability of acoustic isolation measurements. The methodology involved varying the positions of the acoustic source and microphones, as well as the temperature and humidity. The statistical treatment of the data followed the recommendations of ISO 140 II, and the repeatability was calculated for a confidence level of 95%. The laboratory's chambers for emitting and receiving sound were made of reinforced concrete and had volumes of 60 and 67 m3, respectively. The chambers were supported by neoprene isolators and had double doors with acoustic seals. The laboratory's equipment was capable of measuring acoustic pressure and reverberation times in accordance with ISO R 354. The article concludes that the laboratory's facilities and measurement procedures are precise and operational, and that further studies should be conducted on the influence of reverberation time on acoustic isolation measurements.