ISO INTERNATIONAL STANDARD 15186-3 First edition 2002-11-01 Acoustics Measurement of sound insulation in buildings and of building elements using sound intensity Part 3: Laboratory measurements at low frequencies Acoustique - Mesurage par intensite de lisolation acoustique des immeubles etdes élementsdeconstruction- Partie 3: Mesurages en laboratoire a de basses frequences Reference number ISO 15186-3:2002(E) ISO IS0 15186-3:2002 Contents Page 1 Scope 1.1General 1.2 Precision 2Normative references Terms and definitions 2 4 Instrumentation 4 4.1 General 4 4.2 Calibration 5 5 Test arrangement . 5 5.1 Rooms 5.2 Test specimen. 5 5.3Mounting conditions 6 6Testprocedure 6 6.1 General .... 6 6.2 Generation of sound field .... 6 in the source room ......... 6 6.4Measurement of the average sound intensity level on the receiving side ..... 7 6.5Background noise... 9 6.6Frequencyrangeofmeasurements 10 7 Expression of results 10 8 Test report 10 Annexes 11 AQualification B Estimated precision of the method. 13 Bibliography.. 14 ili IS015186-3:2002 Foreword ISo(the International OrganizationforStandardization)is aworldwidefederationof nationalstandardsbodies(iso committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas liaison with isO, also take part in the work. isO collaborates closely with the International Electrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75%of the memberbodies casting a vote Attention is drawn to the possibility that some of the elements of this part of isO 15186 may be the subject of patent International Standard ISO15186-3 was prepared by Technical Committee ISO/TC 43,Acoustics, Subcommittee SC 2, Building acoustics. Iso 15186 consists of the following parts, under the general title Acoustics —Measurement of sound insulation in buildings and of building elements using sound intensity: Part1:Laboratory measurements — Part 2: In-situ conditions Part3:Laboratorymeasurementsatlowfrequencies iv IS015186-3:2002 Acoustics Measurement of sound insulation in buildings and of building elements using sound intensity Part 3: Laboratory measurements at low frequencies 1 Scope 1.1 General This part of IsO 15186 specifies a sound intensity method to determine the sound reduction index and the element normalized level difference of building elements at low frequencies. This method has significantly better reproducibility in a typical test facility than those of ISO 140-3, ISO 140-10 and ISO 15186-1. The results are more mainly intended for the frequency range 50 Hz to 80 Hz. NOTE For elements faced with thick, porous absorbers, the recommended frequency range is 50 Hz to 80 Hz. The main differences between the methods of ISO 15186-1 and ISO 15186-3 are that in ISO 15186-3 The results found by the method of ISO 15186-3 can be combined with those of ISO 140-3 and ISO 15186-1 to produce data in the frequency range 50 Hz to 5 000 Hz. 1.2 Precision with the method of ISO 140-3 at 100 Hz. Some comparisons of data obtained with the methods of this part of ISO 15186 and ISO 140-3 are given in annex B. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of isO 15186. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply.However, parties to agreements based on this part of isO 15186 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of cur