AS 1045-1988

1 - AS 1045-1988 ACOUSTICS - MEASUREMENT OF SOUND ABSORPTION IN A REVERBERATION ROOM
4 - PREFACE
5 - CONTENTS
6 - FOREWORD
7 - SECTION 1. SCOPE AND GENERAL
7 - 1.1 SCOPE.
7 - 1.2 APPLICATION.
7 - 1.3 PRINCIPLE OF THE METHOD.
7 - 1.4 STANDARD DEVIATION OF MEASUREMENTS.
7 - 1.5 REFERENCED DOCUMENTS.
7 - 1.6 DEFINITIONS.
7 - 1.6.1 Reverberation time
7 - 1.6.2 Equivalent sound absorption area of a room
7 - 1.6.3 Equivalent sound absorption area of a test specimen
7 - 1.6.4 Sound absorption coefficient
7 - 1.6.5 Repeatability standard deviation (s)
7 - 1.6.6 Reproducibility standard deviation
9 - SECTION 2. INSTRUMENTATION
9 - 2.1 SIGNAL GENERATION.
9 - 2.2 SOURCE FILTER OR SPECTRUM SHAPER.
9 - 2.3 LOUDSPEAKERS.
9 - 2.4 MICROPHONES.
9 - 2.5 MEASURING FILTER.
9 - 2.6 RECORDING EQUIPMENT.
10 - SECTION 3. TEST ARRANGEMENT
10 - 3.1 REVERBERATION ROOM AND DIFFUSION OF SOUND FIELD.
10 - 3.1.1 Volume of reverberation room.
10 - 3.1.2 Shape of reverberation room.
10 - 3.1.3 Diffusion of sound field.
10 - 3.1.4 Sound absorption area.
10 - 3.2 TEST SPECIMEN.
10 - 3.2.1 Planar absorbers.
10 - 3.2.2 Discrete sound absorbers.
11 - 3.2.3 Curtains.
11 - 3.3 TEMPERATURE AND RELATIVE HUMIDITY.
12 - SECTION 4. TEST PROCEDURE
12 - 4.1 GENERATION OF SOUND FIELD.
12 - 4.1.1 General.
12 - 4.1.2 Signal spectrum.
12 - 4.2 MEASUREMENT OF REVERBERATION TIME.
12 - 4.2.1 Receiving equipment.
12 - 4.2.2 Evaluation of decay curves.
12 - 4.3 FREQUENCY RANGES FOR MEASUREMENTS.
12 - 4.4 NUMBER OF MEASUREMENTS.
14 - SECTION 5. EXPRESSION OF RESULTS AND TEST REPORT
14 - 5.1 METHODS OF CALCULATION.
15 - 5.2 STATEMENT OF RESULTS.
15 - 5.3 TEST REPORT.
16 - APPENDIX A - DIFFUSIVITY OF THE SOUND FIELD IN THE REVERBERATION ROOM
16 - A1 DIFFUSERS.
16 - A2 CHECK OF DIFFUSIVITY.
17 - APPENDIX B - EXPECTED REPEATABILITY AND REPRODUCIBILITY STANDARD DEVIATIONS FOR ........
17 - B1 REPEATABILITY STANDARD DEVIATION (sR)
17 - B1.1 Theoretical prediction.
18 - B1.2 Calculated example.
19 - B2 REPRODUCIBILITY STANDARD DEVIATION (sR).
19 - B3 REFERENCES.
20 - APPENDIX C - CALCULATION OF AIR ATTENUATION COEFFICIENT

Sets out a method of measuring the sound of absorption coefficient of acoustical materials used as wall or ceiling treatments, of the equivalent sound absorption area of objects such as furniture, persons, or space absorbers, in a reverberation room. It is not intended for measuring the absorption characteristics of weakly damped resonators.

This Standard sets out a method of measuring the sound absorption coefficient of acoustical materials used as wall or ceiling treatments, or the equivalent sound absorption area of objects such as furniture, persons, or space absorbers, in a reverberation room. It is not intended for measuring the absorption characteristics of weakly damped resonators.The results obtained, using the method outlined in this Standard, can be used for comparison purposes and for design calculation with respect to room acoustics and the reduction of the reverberant component of the sound field.